Alcoholics as secret overachievers!

A recent article suggests that  some people may have a genetic predisposition to alcoholism. Dr Alexander Niculescu  and his team, identified 11 “risk” genes (1) that can predict which people are more at prone to becoming alcoholic. For those with a family history of alcoholism, the danger is even greater. All of this can be detected with a simple genetic test.

“Having a family history already suggests that there is a genetic risk that’s being transmitted. Those people should not expose themselves to temptation and drink even small amounts, as they are more prone to go down a slippery slope of higher amounts of alcohol and full-blown alcoholism,” Dr Niculescu said.

Dr Niculescu said these gene variants also have a lot to do with drive and compulsions, which can be used for positive things like professional achievement. “What we are discovering at the biological level is that there is this physiological robustness and drive that goes hand in hand with predisposition or compulsion to alcoholism and if you manage to avoid getting sucked into alcoholism and just use your biological endowments and drive for other things, you might be an overachiever in other areas.”

In the conclusion to the article it states that  it is likely at its core a disease of an exogenous agent (alcohol) modulating different mind domains/dimensions (anxiety, mood and cognition) precipitated by environmental stress on a background of genetic vulnerability (2).

In simple language, this is what we have been suggesting in this blog. Alcohol acts on underlying mechanisms  relating to anxiety, mood, cognition, which we view under the umbrella term of emotional regulation and processing deficits.

It also shows how genetic vulnerability may overlap with other psychiatric disorders, overlap does not mean the same as.

 

 

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The oft cited co-morbidities which supposedly co-occur alongside alcoholism are in fact not co-morbidity in our view  but intrinsic to the condition. Although this argument and article at least acknowledges there is a growing debate about what constitutes co-morbidity and pathology in alcoholism.

For us alcoholism is these so-called “co-morbidities” mixed with the deleterious effects of chronic alcohol on these deficits and which are commonly exacerbated pre-morbidity or before the actual start of alcohol use by traumatising or distressing early childhood experiences which have been known to result in both stress and emotional dysregulation which in turns leads to a heightening of the rewarding effect of alcohol (or drugs) as stress chemicals increase dopamine in reward networks such as the nucleus accumbens. Alcoholics find a “solution” to their emotional difficulties in the the heightened, calming effects of alcohol and eventually find in the course of time and chronic use that they cannot do without it.

For us genetically, this research is showing what manifestly, in terms of emotional and behavioural problems, is being shown by cognitve, affective and clinical neuroscience.

It also explains why so many recovering alcoholics surprise us and themselves, especially those underachievers at school of which I am one, with their vigour, intelligence and achievements in recovery once they have climbed out of their own personal hell of active alcoholism.

It also explains how they physically survived ordeals which would have killed most. 

References

Levey, D. F., Le-Niculescu, H., Frank, J., Ayalew, M., Jain, N., Kirlin, B., … & Niculescu, A. B. (2014). Genetic risk prediction and neurobiological understanding of alcoholism. Translational psychiatry4(5), e391.

Niculescu AB 3rd, Schork NJ, Salomon DR. Mindscape: a convergent perspective on life, mind, consciousness and happiness. J Affect Disord2010; 123: 1–8. |

Don’t fight your thoughts!

The idea that abstinence will automatically also decrease alcohol-related intrusive thoughts has been dismissed by research and vast anecdotal evidence.

Practically all therapies for alcoholism e.g  AA, SMART and so on suggest that urges create automatic thoughts about drinking. This has been demonstrated in research that distress automatically gives rise to intrusive thoughts about alcohol. (1) This reflects emotional dysregulation as these intrusive thoughts are correlated to emotional dysregulation (2).

These thoughts to the recovering/abstinent individual can be seen as egodystonic which is a psychological term referring to behaviors, values, feelings that are in harmony with or acceptable to the needs and goals of the ego, or consistent with one’s self image.  Other conditions, such as OCD, have these egodystonic thoughts creating the distress that drives a compulsive need to act on them, rather than letting them pass. In other words, these thoughts are seen as distressing and threatening and compel one to act to reduce this escalating sense of distress. A similar process can happen to those in early recovery. Thoughts about drinking or using when you now wish to remain in recovery are egodystonic, they are contrary to the view of oneself as a person in recovery.  The main problem occurs when we think we can control these thoughts are that these thoughts mean we want to drink or are going to relapse!

Early recovery is a period marked by heightened emotional dysregulation and the proliferation of intrusive thoughts about alcohol .

In fact, empirical research demonstrates that alcohol-related thoughts can resemble obsessive-compulsive thinking (3,4).

In fact, one way to measure “craving” in alcoholics is by scale called the Obsessive Compulsive Drinking Scale (5) , thus highlighting certain similarities in pathomechanisms between alcohol and OCD.

This finding is also supported by clinical observation and leads to the expectation that among abstinent alcohol abusers, alcohol-related thoughts and intrusions are the rule rather than the exception (6)

Relatively little is known about how alcohol abusers appraise their alcohol-related thoughts. Are they aware that alcohol-related thoughts occur naturally and are highly likely during abstinence? Or do they interpret these thoughts in a negative way, for example, as unexpected, shameful, and bothersome? Answers to these questions obviously inform with implications for relapse prevention, because misinterpretations of naturally occurring thoughts may be detrimental for abstinence (7).

 

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A number of conceptual papers and empirical studies have shown that individuals’ appraisal of their intrusive thoughts as detrimental and potentially out of their control may lead them to dysfunctional and counterproductive efforts to control their thinking. Alcohol-related thoughts cause an individual to experience strong emotional reactions; however, alcohol abusers will increase their efforts to control their thinking only when they have negative beliefs about these thoughts. For instance, spontaneous positive memories about alcohol (‘‘It was so nice to hang out at parties and to drink with my buddies’’) may be appraised—and misinterpreted—as ‘‘the first steps toward a relapse’’.

Such an appraisal of one’s thoughts about alcohol as problematic may instigate thought suppression and other efforts to control the thoughts. Because these efforts must be assumed to be counterproductive (Fehm & Hoyer, 2004), they will increase rather than prevent negative feelings and thoughts, and they may even demoralize alcohol abusers who are trying to remain abstinent

If positive alcohol-related thoughts are not appraised as problematic but as a normal part of abstinence, the awareness of these thoughts might even lead to the selection of more adaptive coping responses, which could help to reduce the risk of relapse.

In the context of mental health, metacognition can be loosely defined as the process that “reinforces one’s subjective sense of being a self and allows for becoming aware that some of one’s thoughts and feelings are symptoms of an illness.”

The assumption that metacognition mediates reactions to alcohol-related cues may help to explain why “craving” does not inevitably lead to relapse.

In one reported study (8), participants who reported on their thoughts about alcohol in the previous 24 hours, 92% reported experiencing at least some thoughts about drinking that ‘‘just pop in and vanish’’ without an attempt to eliminate them. This suggests that if both suppression and elaboration can be avoided, many intrusive thoughts will be relatively transient.

An “accept and move on’’ strategy provides an opportunity for the intrusion to remain a fleeting thought.

 

References

1. Zack, M., Toneatto, T., & MacLeod, C. M. (1999). Implicit activation of alcohol concepts by negative affective cues distinguishes between problem drinkers with high and low psychiatric distress. Journal of Abnormal Psychology108(3), 518.

2. Ingjaldsson, J. T., Laberg, J. C., & Thayer, J. F. (2003). Reduced heart rate variability in chronic alcohol abuse: relationship with negative mood, chronic thought suppression, and compulsive drinking. Biological Psychiatry54(12), 1427-1436.

3. Caetano, R. (1985). Alcohol dependence and the need to drink: A compulsion? Psychological Medicine, 15(3), 463–469

4. Modell, J. G., Glaser, F. B., Mountz, J. M., Schmaltz, S., & Cyr, L. (1992). Obsessive and compulsive characteristics of alcohol abuse and dependence: Quantification by a newly developed questionnaire. Alcoholism: Clinical and Experimental Research, 16(2), 266–271.

5. Anton, R. F., Moak, D. H., & Latham, P. (1995). The Obsessive Compulsive Drinking Scale: A self-rated
instrument for the quantification of thoughts about alcohol and drinking behavior. Alcoholism:
Clinical and Experimental Research, 19, 92–99.

6. Hoyer, J., Hacker, J., & Lindenmeyer, J. (2007). Metacognition in alcohol abusers: How are alcohol-related intrusions appraised?. Cognitive Therapy and Research31(6), 817-831.

7. Marlatt, G. A., & Gordon, J. R. (Eds.). (1985). Relapse prevention: Maintenance strategies in the
treatment of addictive behaviors. New York: Guilford Press

8. Kavanagh, D. J., Andrade, J., & May, J. (2005). Imaginary relish and exquisite torture: the elaborated intrusion theory of desire. Psychological review112(2), 446.

 

Do I still have an “Alcoholic Mind”!?

When I first came into recovery I used to get frightened by other abstinent  alcoholics proclaim that they were so glad they did not get the “wet tongue” when they saw alcohol or people drinking alcohol.  I used to feel ashamed as I did have an instantaneous “wet tongue” or mild salivation (Pavlovian response) and still do  years later when I see people drinking alcohol. Is this a “craving” for alcohol, do I still want to drink? Do I still have an “alcoholic mind?“. Did I do my steps properly?

It used to churn me up, these so-called alcoholics who had no physiological response to alcohol-related “cues”.

Part me also thought it was linked to addiction severity, how bad or chronic one’s alcoholism become, how far down the line or how low your rock bottom was? There may some validity in that observation.

It was partly because of mixed messages from alcoholics and from various medical doctors that I decided to take matters into my own hands and do some research into my alcoholic brain.

What I have discovered is that I have an “alcoholic brain” and not a “alcoholic mind” and there is a huge difference. So if there are people out there relatively new to recovery, listen up. For chronic alcoholics there is an automatic physiological response when we see cues such as other people drinking. Mild salivation, quickening heart rate etc. These are automatic, habitual, it happens to us rather than us wanting or willing it to happen. It happens unconsciously without our say so!

If you get a “wet tongue” i.e. you mildly salivate, then this is what happens when you have crossed the line into chronic alcoholism. Loads of studies have shown there is this automatic response and have also shown there is also an attentional bias to alcohol cues. We notice alcohol cues in the environment before anything else. They have a heightened “noticeableness”.

Have ever been in a new town and counted the number of drinking establishments automatically or had a heightened awareness of half drunken bottles of alcohol lying in the street? This is an attentional bias, we notice alcohol related stuff before anything else.

Some researchers in science call this a craving. I disagree. I call this an physiological urge, distinct from craving. I think a craving is more akin to a “mental obsession” about alcohol. Alcohol has only had ‘luring’ effect on me while very emotional distressed or in the early days of recovery I was very scared that  I would drink but, looking back, I never had any desire to.

It is hugely important for recovering persons that we distinguish between urges and craving, in a clear manner that science seems to have been unable to do! Lives can depend on this. We are so vulnerable in early recover that we need sound direction on what is happening to us automatically and what we are encouraging to happen, consciously.

An urge for me is a physiological response to cues, external and internal (e.g. stress). A craving is different but interlinked.

Let me explain. If I have an urge and it becomes accompanied by automatic intrusive thoughts such as a drink would be nice, and maybe a suggestion on where to get this drink, this does not mean I want a drink. It is simply automatically prompted intrusive thoughts, the type of thought I used to get all the time and so became habitual, stored away in an automatized addiction schema or addiction action plan.

If I realize this and simply let these thoughts go, i.e. do not react to them, then they lessen and dissipate altogether.

This is not a craving. I have not consciously and emotionally engaged with these intrusive thoughts (although we often do in early recovery when they scare the life out of us!).

If I consciously engage, emotionally react, to these thoughts either because I want a drink (elaboration of these thoughts as in embellishing a desire state) or the thought scares the life out of me (averse reaction) I can end up in a mental obsession. If in recovery, we try to suppress these thoughts then they will come back stronger than before which will raise  already high stress levels and recruit a whole host of memories of why I should drink, with who, where, and how much I will enjoy it. They will also activate an Alcoholic Self Schema (different to the recovery self schema still being formed in early recovery).  Then I have a memory Hydra effect where attempting to suppress this terrible flowering of desire based memories or to cut off the heads of these thoughts and memories leads to them increasing and increasing.

 

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Then there are lots of these memories driving you crazy and scaring the life out of you.  And this is in someone who does not want to drink but wants to remain in recovery!!? The other guy who is embellishing these thoughts is kinda thinking about drinking or toying with the possibility, so but again he is reacting cognitively and consciously to these intrusive thoughts. He is elaborating on them. He is using a different more cognitive part of the brain and a different memory system to those activated when he was simply having unconscious, habitual, automatic intrusive thoughts. He is now involved in this process rather than it simply happening to him.

So what I am saying is that there is no simple urge state that automatically leads to drink. We have to cognitively and emotionally react to it.

In my time in recovery, I have rarely heard of or witnessed  someone lured siren-like by a cue to a drink and when I have it is because he wanted to drink really, was testing their alcoholism, or e was in huge emotional distress and went “to hell with it!”

As we will see in later blogs, stress and cues certainly do not mix but again there is still a cognitive-emotional reaction which mediates between an urge and a relapse!

What is craving – do neurobiological accounts explain relapse in recovering alcoholics? Pt 2

If you want to drink, you will. It you do not, and depending on your regulation of emotions and stress, you may still relapse, even if one never intended to drink again.

In our previous blog we looked at automatic physiological response to cues that alcoholics appear to experience. These habitual responses are well explained by reinforcement, conditioning or neurobiological models of addiction.

However, do these neurobiological models predict relapse in abstinent alcoholics and addicts? In other words, do recovering alcoholics act and react to cues and have the same attentional bias, i.e. are they lured siren-like to alcohol or drug cues like lemmings to a drink or a drug or are there more  cognitive-affective processes at work in the craving than these models suggest!?

Does the mind play a role in transmuting these physiological urges into “craving”.

When I have seen a new comer to recovery craving they do not seem to walk around like a robot, salivating and rubbing their sweaty hands together. I have seen that when I was in active drinking and was like that innumerable times myself while under the spell of this “fleshy hunger” called having a pathological urge for a drink.

I am not downplaying this urge state, it is quite horrendous, it is like craving a glass of water after days in the desert. It feels like your very life depends on it, in other words. It can be a life or death feeling.

 

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In recovery, this urge state becomes more complicated and various other brain regions may become involved in this “craving” and there may be a interplay between regions rather than regions simply acting in concert – we will explore this more in series 3 of this theme of “craving”.

For now we examine how well do neurobiological accounts (i.e. accounts which focus primarily on impairments in neurotransmitter and stress systems and brain function in areas which create a cascade of ‘knock on’ impairment and dysfunction in areas of the prefrontal cortex which deals with cognitive control of behaviour with resultant dysfunction in areas which deal with reward, motivation stress and emotional response and more motoric, habitualized action) predict behaviour in abstinent, treatment seeking individuals?

Here we simply consider how well aspects of these theories, such as the ideas relating to craving (urge) via cue reactivity (an attentional bias towards alcohol and drug associated cues in the environment)  and positive memory associations for previous alcohol or drug use, relate to, or are relevent to the experiential reality of everyday recovering alcoholics and addicts.

In simple terms, it is the duty of science to attempt to predict behaviour, so how well do these models, especially the positive reinforcement model, predict the behaviour of treatment seeking abstinent alcoholics and addicts. 

Factors in relapse

Cues, external especially, which is a central part of positive reinforcement models, seem to be only one of various factors in relapse. They are present in a relatively small minority of studies or interact with other variables such as stress and negative affect (NA). So how well does this then validate this theory of addiction, when it is only present in a minor way in relapse and usually alongside stress and NA. Does this mean it plays a role when interacting with these variables of stress/NA. Does it play a role on it’s own?

I forward this question because the looking at an alcohol cue by an alcoholic even in recovery/abstinence invokes stress reactions such as anxiety or negative emotions such as anger, sadness ( ). Can we say there is a non-stress influenced cue-reactivity? Is there a purely dopaminergic cue reactivity? It doesn’t appear so.

In fact moving on from noting this intrinsic stress response in cue reactivity, various studies show that the highest high-risk relapse situations are negative emotions, testing personal control, social pressure, and urge and temptations  (1), that 62 –73% of relapse episodes were due to negative emotion and social pressure. Heroin addicts relapse primarily because of NE and lack of social supports. Mood state, along with social isolation and family factors, was more likely to be related to relapse incidences with a positive correlation between NE and alcohol-seeking behaviour. Thus the most commonly cited reason for relapse was negative mood states, consistent with previous studies of relapse factors (2).  Also reasons for relapse did not differ in relation to the primary drug of dependence (alcohol, methamphetamine, heroin), reflecting the commonality of relapse processes across diverse types of substances.

Marlatt (3,4) , views relapse as an unfolding process in which resumption of substance use is the last event in a long sequence of maladaptive responses to internal or extemal stressors such as negative emotional states, interpersonal conflicts, and social pressures. In fact negative emotional states ….coping, self-efficacy and stressful life events appeared to be of greater import in determining relapse than ‘cues’.

It would appear that cue associated stimuli plays a minor role in relapse, with stress and NA appearing to be a more important determinant of relapse. So conditioning models do not appear to give a comprehensive account of relapse and this may be particularly the case in abstinent, treatment seeking alcoholics.

How does conditioning methodology adequately explain this group?

Attentional Bias

Do treatment seeking alcoholic have the same attentional bias as non treatment seeking active alcoholics?

In fact, studies seem to show a negative attentional bias in alcohol-dependent patients that may be interpreted as an avoidance of alcohol-related stimuli.

Townshend and Duka (2007) propose that treatment seeking individuals have established active avoiding strategies and  are able to disengage their attention from alcohol cues (5). In fact is suggested that a positive attentional bias towards alcohol cues occurs when stimuli were presented shortly (50 ms), followed by a disengagement from alcohol cues in the 500 ms interval of cue presentation. This corresponds with a cognitive model of craving of Tiffany (6) where the 50ms may represent automatic approach before this automatic bias is interfered with by cognitive control, perhaps resulting in ‘craving’.

Does this visual approach–disengagement pattern reflect an  attentional bias which is appetitive or threat based? If there is avoidance are cues similar as  seen as in those with trait anxiety who have attentional bias for threat-related cues (7). A large body of evidence indicates that aversive emotional states are associated with biases in cognitive processing and, specifically, with increased attentional processing of threat-related cues.Is this also how treatment seeking addicted individuals are responding to substance-related cues? It may that stress heightens the salience of attractiveness of the cues so that abstinent individual relapse because of stress based response which makes relapse via internal and external cues a solution to their chronic stress/emotional distress?

Or it may be that relapse is based on difficulties coping with the manifestation of chronic stress, emotional distress and that  relapse  is a more complicated process than simply being lured, siren-like, to relapse via cues.

In most of the relapses we have encountered it has been a ongoing build up to relapse. There has been a period of emotional dyregulation whereby individuals get more and more distressed, often in inter-personal relationships, and have a “to hell with it!” relapse to relieve escalating emotional distress and the distorted thinking that goes with it. It is not due to automatic or motoric proceses, it is mediated via affective-cognitive mechanisms and this is why the information processing model, with some modifications, appears to explain craving and relapse more satisfactorily.

If you want to drink, you will, it you do not, and depending on your regulation of emotions and stress, you may still relapse, even if one never intended to drink again, due to the torturous intrusive thoughts which accompany this cognitive and emotionally based “craving”, more akin to the “mental obsession ” of AA’s Big Book than purely physiological urges.

References

1. El, S., Salah El, G., & Bashir, T. Z. (2004). High-risk relapse situations and self-efficacy: Comparison between alcoholics and heroin addicts. Addictive behaviors29(4), 753-758.

2.  Hammerbacher, M., & Lyvers, M. (2006). Factors associated with relapse among clients in Australian substance disorder treatment facilities. Journal of substance use11(6), 387-394.

3. Marlatt, G.A. (1978) Craving for alcohol, loss of control and relapse: Cognitive behavioural analysis. In: Nathan, P.E., Marlatt, G.A., and Loberg, T. eds. Alcoholism: new directions in behavioural research and treatment. Plenum Press, New York, 271-314.

4. Marlatt, G.A., and Gordon, J.R. (1985). Relapse prevention: maintenance strategies in the treatment of addictive behaviors. Guilford  Press, New York.

5. Townshend JMDuka Attentional bias associated with alcohol cues: differences between heavy and occasional social drinkersPsychopharmacology (Berl)2001;157:6774.

6. Tiffany, S. T. (1990). A cognitive model of drug urges and drug-use behavior: role of automatic and nonautomatic processes. Psychological review97(2), 147.

7.  Bar-Haim, Y., Lamy, D., Pergamin, L., Bakermans-Kranenburg, M. J., & van IJzendoorn, M. H. (2007). Threat-related attentional bias in anxious and nonanxious individuals: a meta-analytic study. Psychological bulletin133(1), 1.

8.  McCusker CG  Cognitive biases and addiction: an evolution in theory and methodAddiction 2001;96:4756.

What is craving?

When I first came into recovery I used to get frightened by other abstinent  alcoholics proclaim that they were so glad they did not get the “wet tongue” when they saw alcohol or people drinking alcohol.  I used to feel ashamed as I did have an instantaneous “wet tongue” and still do  years later when I see people drinking alcohol. Is this a “craving” for alcohol, do I still want to drink? Do I still have an “alcoholic mind?“.

It used to churn me up, these so-called alcoholics who had no a  physiological response to alcohol-related “cues”.

What I have discovered is that I have an “alcoholic brain” and not a “alcoholic mind” and there is a huge difference. So if there are people out there relatively new to recovery, listen up. For chronic alcoholics there is an automatic physiological response when we see cues such as other people drinking. Automatic, habitual, it happens to us rather than us wanting or willing it to happen. It happens unconsciously without our say so!

Some researchers in science call this a craving. I disagree. I call this an physiological urge, distinct from craving. I think a craving is more akin to a “mental obsession” about alcohol.

It is hugely important for recovering persons that we distinguish between urges and craving, in a clear manner that science seems to have been unable to do! Lives can depend on this. We are so vulnerable in early recover that we need so sound direction on what is happening to us automatically and what we are encouraging to happen, consciously.

An urge for me is a physiological response to cues, external and internal (e.g. stress). A craving is different but interlinked.

If I have an urge and it becomes accompanied by automatic intrusive thoughts such as a drink would be nice, and maybe a suggestion on where to get this drink, this does not mean I want a drink. It is simply automatically prompted intrusive thoughts, the type of thought I used to get all the time and so became habitual, became stored away in an automatized addiction schema or addiction action plan.

If I realize this and simply  these thoughts go, i.e. do not react to them, then they lessen and dissipate altogether.

This is not a craving. I have not consciously and emotionally engaged with these intrusive thoughts.

So what I am saying is that there is no simple urge state that automatically leads to drink. We have to cognitively and emotionally react to it.

In my time in recovery, I have rarely heard of or witnessed  someone lured siren-like by a cue to a drink and when I have it is because he wanted to drink really, were testing their alcoholism, or that he was in huge emotional distress and went to “hell with it!”. As we will see below, stress and cues certainly do not mix but again there is still a cognitive-emotional reaction which mediates between an urge and a relapse!

In the first of a four part series of blogs we discuss “what is craving?” and consider whether the emotional dysregulation we consider to be at the heart of alcoholism and addiction also plays a role in both craving and relapse.

We start this series by considering the neurobiological accounts of craving and will then consider how well these accounts explain craving and relapse in abstinent, treatment seeking, or recovering alcoholics and addicts.

Part 1

What is craving?

Craving persists years into abstinence (1).

Precise definitions of craving have remained elusive (2-5). Two general categories are based on conditioning and cognitive mechanisms (6) but are not mutually exclusive.

A Neuroadaptive Model of Craving – Scientists believe that a gradual and, perhaps, permanent adaptation of brain function (i.e., neuroadaptation) to the presence of alcohol is a central feature in the development of alcohol dependence (7,8).

Conditioning Models – The “conditioning” models posit that cues elicit the same physiological and psychological response as drug consumption itself  with these ‘respondent’ conditioning theories predicting that responses to drug-related cues either reflect aversive abstinence symptoms or mimic drug effects  have dominated explanatory models in cue reactivity studies (9).

The definition of addiction by the American Society of Addiction Medicine (ASAM) includes the terms craving and persistent risk, and emphasises risk of relapse after periods of abstinence triggered by exposure to substance-related cues and emotional stressors (10).

This conceptualisation points to the role of substance-related cues, e.g., environmental stimuli that are strongly associated with the effects of the administration of substances and acquire incentive salience through Pavlovian conditioning, as well as stress (an internal cue), as major determinants of relapse.

The Incentive Sensitisation (IS) Model (11), addiction is the result of neural sensitisation of reward circuits (centred in the ventral striatum (VS)) by the neurotransmitter dopamine. Positive reinforcement mechanisms lead to a non-associative learning process, referred to as sensitization, in which repeated confrontation with a substance-related cue (which acts as a reinforcer) results in the progressive amplification of a response (substance seeking).

This ‘sensitisation’ or hypersensitivity may be independent of negative withdrawal symptoms or an individual’s general negative emotional state and leads to compulsive substance-seeking and substance-taking. These mechanisms of positive reinforcement leave addicts vulnerable to relapse when confronted with substance-related cues that trigger a pathological “wanting”. In short, IS produces a bias of attentional processing towards substance-associated stimuli and a pathological wanting of alcohol or substances. Sensitisation and attentional bias have been demonstrated in various studies (12,13).

Negative reinforcement model of addiction Basic negative reinforcement models pose that addictive behaviour is the consequence of persistent negative affect (NA). This NA is associated with maladaptive changes in the brain’s stress and reward circuits, which leave addicts vulnerable to cue-associated stimuli prompting a desire to relieve their negative emotional states (14).

One prominent stress-based negative reinforcement model, the Hedonic Dysregulation (HD) Model, mainly associated with Koob and le Moal (14), In sum, the HD model posits that, in substance dependent individuals,  an overactive stress  axis creates a progressive allostasis in the brain reward systems which underlies transition from substance use to addiction and creates a persistent state of NA (altered and excessive stress) and emotional reaction to “cues”. These changes continue to persist even when an addicted individual experiences a state of protracted abstinence.

Persistent NA increases their incentive salience and desire to use substances in an attempt to relieve this NA.

Evidence for the involvement of both the reward and the stress system of the brain  comes from imaging studies of addicted individuals during withdrawal or protracted abstinence, which have shown decreases in dopamine D2 receptor density (hypothesized to reflect hypodopaminergic function) (15) as well as alteration in brain stress systems, such as increase in CRF and glucocorticoids (16).

These models to me appear to be describing urges based on cues and the effect of cues with stress/emotional distress. This last one can impact on recovery and relapse mentioned in another blog.

The question remains however whether these neurobiological models predict relapse in abstinent alcoholics and addicts?

 

References 

1.  Anton, R. F. (1999). What is craving. Alcohol Research and Health23(3), 165-173.

2. LUDWIG, A.M., AND STARK, L.H. Alcohol craving: Subjective and situational aspects. Quarterly Journal of Studies on Alcohol 35:899–905, 1974.

3. KOZLOWSKI, L.T., AND WILKINSON, D.A. Use and misuse of the concept of craving by alcohol, tobacco, and drug researchers. British Journal of Medicine 82:31–45, 1987.

4.  KOZLOWSKI, L.T.; MANN, R.E.; WILKINSON, D.A.; AND POULOS, C.X. “Cravings” are ambiguous: Ask about urges and desires. Addictive Behaviors 14:443–445, 1989

5.  SITHARTHAN, T.; MCGRATH, D.; SITHARTHAN, G.; AND SAUNDERS, J.B. Meaning of craving in research on addiction. Psychological Reports 71:823–826, 1992.

6. SINGLETON, E.G., AND GORELICK, D.A. Mechanisms of alcohol craving and their clinical implications. In: Galanter, M., ed. Recent Developments in Alcoholism: Volume 14. The Consequences of Alcoholism. New
York: Plenum Press, 1998. pp. 177–195.

7. Robinson, T.E., & Berridge, K.C. (1993). The neural basis of drug craving: An incentive-sensitization theory of addiction. Brain Research, 18, 247-291

8. Koob GF, Le Moal M. Drug abuse: hedonic homeostatic dysregulation. Science. 1997;278:52–58

9.  Ingjaldsson, J. T., Laberg, J. C., & Thayer, J. F. (2003). Reduced heart rate variability in chronic alcohol abuse: relationship with negative mood, chronic thought suppression, and compulsive drinking. Biological Psychiatry54(12), 1427-1436.

10.  Morse RM, Flavin DK (1992). “The definition of alcoholism. The Joint Committee of the National Council on Alcoholism and Drug Dependence and the American Society of Addiction Medicine to Study the Definition and Criteria for the Diagnosis of Alcoholism“. JAMA 268 (8): 1012–4

11. Robinson, T. E., & Berridge, K. C. (2008). The incentive sensitization theory of addiction: some current issues. Philosophical Transactions of the Royal Society B: Biological Sciences, 363(1507), 3137-3146

12. Leyton M. Conditioned and sensitized responses to stimulant drugs in humans. Prog. Neuropsychopharmacol. Biol. Psychiatry. 2007;31:1601–1613.

13. Franken, I. H. (2003). Drug craving and addiction: integrating psychological and neuropsychopharmacological approaches. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 27(4), 563-579

14. Koob, G. F., & LeMoal, M. (2001). Drug addiction, dysregulation of reward, and allostasis. Neuropsychopharmacology, 24, 97–129.

15. Volkow ND, Wang GJ, Fowler JS, et al. Decreased striatal dopaminergic responsiveness in detoxified cocaine-dependent subjects. Nature. 1997;386:830–3.

16.. Koob GF, Le Moal M. Addiction and the brain antireward system. Annu Rev Psychol. 2008;59:29–53

How meditation helps with “emotional sobriety”!

In this blog we have considered two main and fundamental areas:-

1. that alcoholism appears to be an emotional regulation and processing disorder which implicates impaired functioning of brain regions and neural networks involved in regulation and processing emotion such as the insular cortex, anterior cingulate cortex and dorsolateral prefrontal cortex.

2. that in early and later recovery there appears to be increased functioning in these areas especially the dorsolateral prefrontal cortex (dlPFC) and anterior cingulate cortex (ACC) which is important not only in regulating emotions but also in abstinence success.

Our third point is that mediation, of various types, appears to strengthen the very areas implicated in emotional regulation and processing, which ultimately helps with “emotional sobriety” and long term recovery.

Various studies have shown that mindfulness mediation training in expert meditators, as well as novices,  influenced areas of the brain involved in attention, awareness and emotion (1,2).

 

Meditation-in-Brain-660

 

A key feature of mindfulness meditators may be the ability to recognise and accurately label emotions (3). Brain FMRI studies have shown more mindful people having increased ability to control emotional reactions in various areas associated with emotional regulation such as the amgydala, dlPFC, and ACC (4).

In a study (5) on the the effects of long term meditation on physical structure of the above brain regions, practitioners of mindful meditation who meditated 30-40 minutes a day, had increased thickness due to neuroplasticity of meditation in brain regions associated with attention and interoception (sensitivity to somatic or internal bodily stimuli) than the matched controls used in this study. Again the regions observed to have greater thickness via increased neural activity (neuroplasticity) were the PFC, right insula (interoception and this increased appreciation of bodily sensations and emotions) as well as the ACC in attention (and possible self awareness as ACC is also linked to consciousness) .

A structural MRI study (6) showed that experienced mindfulness meditators also had increased grey matter the right interior insula and PFC as well as, in unpublished data, in the hippocampus, which is implicated in memory but also in stress regulation. Thus mindfulness meditation and the fMRI and MRI studies show it is possible to train the mind to change brain morphology and functionality through the neuroplastic behaviour of meditating.

Brain regions consistently strengthen or which grow additonal “neural muscles” are those associated with emotional regulation and processing such as the dlPFC, ACC, insula and amgydala.   Thus if we want, as recovering individuals,  to shore up our early recovery, by strengthening the brain regions implicated in recovery success we meditate on a regular basis, daily, so that we can also improve those underlying difficulties in emotional regulation and processing.

By relieving emotional distress we greatly lessen the grip our condition has on us on a daily basis, We recover these functions.  We will discuss the role of meditation on reducing emotional distress in later blogs.

 

Image

 

References

1. Cahn, B. R., & Polich, J. (2006). Meditation states and traits: EEG, ERP, and neuroimaging studies. Psychological bulletin132(2), 180.

2,  Lutz, A., Slagter, H. A., Dunne, J. D., & Davidson, R. J. (2008). Attention regulation and monitoring in meditation. Trends in cognitive sciences12(4), 163-169.

3.  Analayo. (2003). Satipatthana: The Direct Path to Awakening. Birmingham, UK: Windhorse Publications.

4.  Creswell, J. D., Way, B. M., Eisenberger, N. I., & Lieberman, M. D. (2007). Neural correlates of dispositional mindfulness during affect labeling.Psychosomatic Medicine69(6), 560-565.

5.  Lazar, S. W., Kerr, C. E., Wasserman, R. H., Gray, J. R., Greve, D. N., Treadway, M. T., … & Fischl, B. (2005). Meditation experience is associated with increased cortical thickness. Neuroreport16(17), 1893.

6. Hölzel, B. K., Ott, U., Hempel, H., Hackl, A., Wolf, K., Stark, R., & Vaitl, D. (2007). Differential engagement of anterior cingulate and adjacent medial frontal cortex in adept meditators and non-meditators. Neuroscience letters421(1), 16-21.

 

see also  Hijacking the Brain

Do people recover without treatment?

I want to comment on an article I read recently which stated some FACTS 1. about  3/4 of individuals in recovery did not use formal treatment or mutual help groups to achieve full, sustained remission. 2.  About 20% of all people with alcohol use disorders recover naturally, without formal treatment or mutual help. Individuals with less severe substance use problems, fewer psychiatric comorbidities and more recovery capital (e.g. social support) have a greater chance of recovering without formal treatment. 4. Self-efficacy, or one’s level of belief in the chances of success is an important predictor of natural recovery success.

http://www.recoveryanswers.org/recovery/natural-recovery/

First of all, it is never a good way to start an article by stating you have FACTS, not good practice. Given this article appeared in a website which I think is great and does good work and has good contributors I was surprised by the claims of this article, which I believe are dangerously misleading to those who actually suffer from alcoholism and are being directed to go it alone. Which of the hundreds of alcoholics I have known over many years, including myself, has not once tried that approach!

This article may be confusing abuse with addiction, they are transitory phases in the addiction cycle, one less severe than the other, so it may be easier to get off the train earlier than later with addiction, if you have no underlying conditions.  

Equally the sample population for studies of this kind often contains people are not actually alcoholic but simply drink too much. Alcholism is more than alcohol. Alcoholism is an underlying psychiatric condition maladaptively treated by alcohol. 

Alcoholism is on a spectrum of severity, with various underlying psychiatric complications. 

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This article is misleading as it then states in it’s “facts” that “individuals who did not utilize formal help or treatment in their recovery process were more likely to have non-abstinent recoveries compared to individuals who did engage in formal substance use help and/or treatment” These so-called non-abstinent recoveries are not recoveries then!

One study (1) examined the rates and predictors of 3-year remission, and subsequent 16-year relapse, among initially untreated individuals with alcohol use disorders who did not obtain help or who participated in treatment and/or Alcoholics Anonymous in the first year after recognizing their need for help. A sample of individuals (n = 461) who initiated help-seeking was surveyed at baseline and 1 year, 3 years, 8 years and 16 years later.

Compared to individuals who obtained help, those who did not were less likely to achieve 3-year remission and subsequently were more likely to relapse.  Among individuals who were remitted (relapsed) at 3 years, those who consumed more alcohol but were less likely to see their drinking as a significant problem, had less self-efficacy, and relied more on avoidance coping, were more likely to relapse by 16 years.

Conclusion – Natural remission may be followed by a high likelihood of relapse; thus, preventive interventions may be indicated to forestall future alcohol problems among individuals who stop or  cut down on their own.

Wont admit Cartoon crop gif

Chronic alcoholism is a condition of severely limited self will or cognitive control over addictive behaviours, as a result we, as recovering alcoholics, need the help of others to act as our external prefrontal cortex, our external cognitive control over subcortical addictive behaviour and our evident emotional dysregulation, until we can do it ourselves more effectively.

I do not remember having a choice in getting off my train earlier, it never occurred to me even as my illness kept the truth about what I had from me. Like many alcoholics I was the last to know.
AA came into being to help those who cannot recover by themselves – like me and countless others who tried but failed. Read The Natural History of Alcoholism by George Vaillant who, over many decades, showed clearly the progression of this disease/disorder, many of his extensive sample also thought they could go it alone, only to find they ultimately needed help or died from their alcoholism. Alcoholism is a fatal condition if left untreated. Sometimes I wish academics who write about it, would consider this when they write about it too.

http://www.amazon.com/The-Natural-History-Alcoholism-Revisited/dp/0674603788

 

References

1. Moos, R. H., & Moos, B. S. (2006). Rates and predictors of relapse after natural and treated remission from alcohol use disorders. Addiction101(2), 212-222.

 

Getting “out of self” through prayer and meditation?

When I first came into recovery I constantly heard the refrain about “getting out of self” – in fact steps 10-12 help one do so. Step 12, by helping others in recovery and step 11 which encourages prayer and mediation. Can we get out of “self” by prayer and mediation? I will be dedicating a number of blogs to mediation so will just briefly consider prayer here. In one study Franciscan nuns had their brains imaged via SPECT which looked at blood-flow in their brains while they were engaged in a type of mystic union called  ‘centring prayer’ which involves opening themselves to being in  the presence of God (and not in “self”). In centring prayer the nuns had a “loss of usual forms of space  During prayer there was demonstrated increase in blood flow in the PFC inferior parietal and inferior frontal lobes  and a decreased flow in the superior parietal lobe, which is related to feelings of “self”.

Centering-prayer

I mention this type of meditation, also because it is a meditation/prayer that I do myself. Click here for more information on this wonderful prayer technique and how it is used by Fr Frank Keating and 12 step groups  – I alternate with this and vispassana meditation which also makes one feel like they are no longer in “self”, that the self is an ephemeral reality, always changing so not static, fixed – the self is thus an illusion in a sense as it is constantly changing. Regardless, of their different origins, both when practiced can transport one to a place seemingly beyond feelings of being in self. The self seems to blend into a widen sense of consciousness without parameters or boundaries such as limited by self. In this state of being, one can view the fleeting images  of the self dispassionately, not being moved by them or reacting to them. Images of the self dissolve like into snow flakes in snow. As we we will see in other blogs, meditation also reduces stress, improves neurotransmission in neurostransmitters effected by chronic addiction, e.g. GABA and strengthens neural regions of the brain that are very important to recovery. The findings of these and other studies of prayer bear some similarity to studies in meditators such as on Tibetan Buddhist meditators (1) so I would not get hung up on the apparent religiosity  or non-religiosity of these ways of meditating. to me they achieve something very similar. It they work they Work! The meditative and spiritual experiences are partly mediated through deactivation of the superior parietal lobe which normally helps to generate the normal sense of “self” (2)

Christianity_Jesus_meditating_golden_light

A  beautiful and enriching respite from self regulation and a profound sense of wholeness, and connection with something beyond self whatever that being beyond self is.  Therapeutically we have to somehow move beyond a reactionary self to a mindful one. From an emotional distressed one to a serene one. The brain is healthier after mediation than before.   As mentioned in other blogs, without emotional distress this condition can be quite dormant.   References 1.  Newberg, A. B., & Iversen, J. (2003). The neural basis of the complex mental task of meditation: neurotransmitter and neurochemical considerations. Medical hypotheses61(2), 282-291. 2. d’Aquili, E. G., & Newberg, A. B. (2000). The neuropsychology of aesthetic, spiritual, and mystical states. Zygon®35(1), 39-51. From Hijacking the Brain

What recovers in Recovery? – Cognitive Control over emotions?

A core aspect of alcohol dependence is poor regulation of behavior and emotion.

Alcohol dependent individuals show an inability to manage the appropriate experience and expression of emotion (e.g., extremes in emotional responsiveness to social situations, negative affect, mood swings) (1,2). Dysfunctional emotion regulation has been considered a primary trigger for relapse (1,3) and has been associated with prefrontal dysfunction.

While current alcohol dependence is associated with exaggerated bottom-up (sub-cortical) and compromised top-down (prefrontal cortex) neural network functioning, there is evidence suggesting that abstinent individuals may have overcome these dysfunctional patterns of network functioning (4) .

Neuro-imaging studies showing chronic alcohol abuse to be associated with stress neuroadaptations in the medial prefrontal and anterior cingulate regions of the brain (5 ), which are strongly implicated in the self-regulation of emotion and behavioral self-control (6).

One study (2) looking at how emotional dysregulation related to relapse, showed compared with social drinkers, alcohol-dependent patients reported significant differences in emotional awareness and impulse control during week 1 of treatment. Significant improvements in awareness and clarity of emotion were observed following 5 weeks of protracted abstinence.

Another study (7) which did not look specifically at emotional regulation but rather on the recovering of prefrontal areas of the brain known to be involved also in the inhibition of  impulsive behaviour and emotional regulation showed that differences between the short- and long-abstinence groups in the patterns of functional recruitment suggest different cognitive control demands at different stages in abstinence.

The long-term abstinent group (n=9) had not consumed cocaine for on average 69 weeks, the short-term abstinent (SA) group (n=9) had an average 0f 2.4 weeks.

Relative to controls, abstinent cocaine abusers have been shown to have reduced metabolism in left anterior cingulate cortex (ACC) and right dorsolateral prefrontal cortex (DLPFC), and greater activation in right ACC.

In this study  the abstinent groups of cocaine addicts showed more elevated activity in the DLPFC ; a finding that has also been observed in abstinent marijuana users (8).

The elevation of frontal activity also appears to undergo a shift from the left to right hemisphere over the course of abstinence.  Furthermore, the left inferior frontal gyrus (IFG) has recently been shown to be important for response inhibition (9) and in a task similar to that described here, older adults have been shown to rely more on left PFC (10). Activity observed in these regions is therefore likely to be response inhibition related.

The reliance of the SA group on this region suggests that early in abstinence users may adopt an alternative cognitive strategy in that they may recruit the LIFG in a manner akin to children and older adults to achieve behavioral results similar to the other groups.

In longer,  prolonged abstinence a pattern topographically typical of normal, healthy controls may emerge.
In short-term abstinence there was an increased inhibition-related dorsolateral and inferior frontal activity indicative of the need for increased inhibitory control over behaviour,  while long-term abstinence showed increased error-related ACC activity indicative of heightened behavioral monitoring.
The results suggest that the improvements in prefrontal systems that underlie cognitive control functions may be an important characteristic of successful long-term abstinence.

Another study (11) noted the loss of grey matter in alcoholism that last from 6–9 months to more than a year or, in some reports, up to at least 6 years following abstinence (12 -14).

It has been suggested cocaine abuse blunts responses in regions important to emotional regulation (15)

Given that emotional reactivity has been implicated as a factor in vulnerability to drug abuse (16)  this may be a preexisting factor that  increased the likelihood of the development and prolonging of drug abuse

If addiction can be characterized as a loss of self-directed volitional control (17),  then abstinence (recovery) and its maintenance may be characterized by a reassertion of these aspects of executive function (18)  as cocaine use has been shown to reduce grey matter in brain regions critical to executive function, such as the anterior cingulate, lateral prefrontal, orbitofrontal and insular cortices (19-24) .

The group of abstinent cocaine addicts (11) reported here show elevations in  (increased) grey matter in abstinence exceeded those of the healthy control in this study after 36 weeks, on average, of abstinence .

One possible explanation for this is that abstinence may require reassertion of cognitive control and behavior monitoring that is diminished during current cocaine dependence.

Reassertion of behavioral control may produce a expansion (25)  in grey matter  in regions such as the anterior insula, anterior cingulate, cerebellum, and dorsolateral prefrontal cortex .

All brain regions implicated in the processing and regulating of emotion. 

 

References

 

 

1. Berking M, Margraf M, Ebert D, Wupperman P, Hofmann SG, Junghanns K. Deficits in emotion-regulation skills predict alcohol use during and after cognitive-behavioral therapy for alcohol dependence. J Consult Clin Psychol. 2011;79:307–318.

2.  Fox HC, Hong KA, Sinha R. Difficulties in emotion regulation and impulse control in recently abstinent alcoholics compared with social drinkers. Alcohol Clin Exp Res. 2008;33:388–394.

3..Cooper ML, Frone MR, Russell M, Mudar P. Drinking to regulate positive and negative emotions: A motivational model of alcohol use. J Pers Soc Psychol. 1995;69:990

4. Camchong, J., Stenger, A., & Fein, G. (2013). Resting‐State Synchrony in Long‐Term Abstinent Alcoholics. Alcoholism: Clinical and Experimental Research37(1), 75-85.

5. Sinha, R., & Li, C. S. (2007). Imaging stress- and cue-induced drug and alcohol craving: Association with relapse and clinical
implications. Drug and Alcohol Review, 26(1), 25−31.

6. Beauregard, M., Lévesque, J., & Bourgouin, P. (2001). Neural correlates of conscious self-regulation of emotion. Journal of
Neuroscience, 21(18), RC165

7. Connolly, C. G., Foxe, J. J., Nierenberg, J., Shpaner, M., & Garavan, H. (2012). The neurobiology of cognitive control in successful cocaine abstinence. Drug and alcohol dependence121(1), 45-53.

8.  Tapert SF, Schweinsburg AD, Drummond SP, Paulus MP, Brown SA, Yang TT, Frank LR. Functional MRI of inhibitory processing in abstinent adolescent marijuana users.Psychopharmacology (Berl.) 2007;194:173–183.[PMC free article]

9. Swick D, Ashley V, Turken AU. Left inferior frontal gyrus is critical for response inhibition. BMC Neurosci. 2008;9:102.[PMC free article]

10. Garavan H, Hester R, Murphy K, Fassbender C, Kelly C. Individual differences in the functional neuroanatomy of inhibitory control. Brain Res. 2006;1105:130–142

11. Connolly, C. G., Bell, R. P., Foxe, J. J., & Garavan, H. (2013). Dissociated grey matter changes with prolonged addiction and extended abstinence in cocaine users. PloS one8(3), e59645.

12. Chanraud S, Pitel A-L, Rohlfing T, Pfefferbaum A, Sullivan EV (2010) Dual Tasking and Working Memory in Alcoholism: Relation to Frontocerebellar Circuitry. Neuropsychopharmacol 35: 1868–1878 doi:10.1038/npp.2010.56.

13.  Wobrock T, Falkai P, Schneider-Axmann T, Frommann N, Woelwer W, et al. (2009) Effects of abstinence on brain morphology in alcoholism. Eur Arch Psy Clin N 259: 143–150 doi:10.1007/s00406-008-0846-3.

14.  Makris N, Oscar-Berman M, Jaffin SK, Hodge SM, Kennedy DN, et al. (2008) Decreased volume of the brain reward system in alcoholism. Biol Psychiatry 64: 192–202 doi:10.1016/j.biopsych.2008.01.018.

15, Bolla K, Ernst M, Kiehl K, Mouratidis M, Eldreth D, et al. (2004) Prefrontal cortical dysfunction in abstinent cocaine abusers. J Neuropsychiatry Clin Neurosci 16: 456–464 doi:10.1176/appi.neuropsych.16.4.456.

16.  Piazza PV, Maccari S, Deminière JM, Le Moal M, Mormède P, et al. (1991) Corticosterone levels determine individual vulnerability to amphetamine self-administration. Proc Natl Acad Sci USA 88: 2088–2092. doi: 10.1073/pnas.88.6.2088

17.  Goldstein RZ, Volkow ND (2002) Drug addiction and its underlying neurobiological basis: neuroimaging evidence for the involvement of the frontal cortex. Am J Psychiatry 159: 1642–1652. doi: 10.1176/appi.ajp.159.10.1642

18. Connolly CG, Foxe JJ, Nierenberg J, Shpaner M, Garavan H (2012) The neurobiology of cognitive control in successful cocaine abstinence. Drug Alcohol Depend 121: 45–53 doi:10.1016/j.drugalcdep.2011.08.007.

19.  Liu X, Matochik JA, Cadet JL, London ED (1998) Smaller volume of prefrontal lobe in polysubstance abusers: a magnetic resonance imaging study. Neuropsychopharmacol 18: 243–252 doi:10.1016/S0893-133X(97)00143-7.

20.  Bartzokis G, Beckson M, Lu P, Nuechterlein K, Edwards N, et al. (2001) Age-related changes in frontal and temporal lobe volumes in men – A magnetic resonance imaging study. Arch Gen Psychiatry 58: 461–465. doi: 10.1001/archpsyc.58.5.461

21. Franklin TR, Acton PD, Maldjian JA, Gray JD, Croft JR, et al. (2002) Decreased gray matter concentration in the insular, orbitofrontal, cingulate, and temporal cortices of cocaine patients. Biol Psychiatry 51: 134–142. doi: 10.1016/s0006-3223(01)01269-0

22.  Matochik JA, London ED, Eldreth DA, Cadet J-L, Bolla KI (2003) Frontal cortical tissue composition in abstinent cocaine abusers: a magnetic resonance imaging study. NeuroImage 19: 1095–1102. doi: 10.1016/s1053-8119(03)00244-1

23.  Lim KO, Wozniak JR, Mueller BA, Franc DT, Specker SM, et al. (2008) Brain macrostructural and microstructural abnormalities in cocaine dependence. Drug Alcohol Depend 92: 164–172 doi:10.1016/j.drugalcdep.2007.07.019.

24.  Ersche KD, Barnes A, Jones PS, Morein-Zamir S, Robbins TW, et al. (2011) Abnormal structure of frontostriatal brain systems is associated with aspects of impulsivity and compulsivity in cocaine dependence. Brain 134: 2013–2024 doi:10.1093/brain/awr138.

25.  Ilg R, Wohlschlaeger AM, Gaser C, Liebau Y, Dauner R, et al. (2008) Gray matter increase induced by practice correlates with task-specific activation: A combined functional and morphometric magnetic resonance Imaging study. J Neurosci 28: 4210–4215 doi:10.1523/JNEUROSCI.5722-07.2008.