Extinction learning is slower, weaker and less context specific after alcohol.

Alcohol is frequently involved in psychological trauma and often used by individuals to reduce fear and anxiety. We examined the effects of alcohol on fear acquisition and extinction within a virtual environment. Healthy volunteers were administered alcohol (0.4g/kg) or placebo and underwent acquisition and extinction from different viewpoints of a virtual courtyard, in which the conditioned stimulus, paired with a mild electric shock, was centrally located. Participants returned the following day to test fear recall from both viewpoints of the courtyard. Skin conductance responses were recorded as an index of conditioned fear. Successful fear acquisition under alcohol contrasted with impaired extinction learning evidenced by persistent conditioned responses (Experiment 1). Participants' impairments in extinction under alcohol correlated with impairments in remembering object-locations in the courtyard seen from one viewpoint when tested from the other viewpoint. Alcohol-induced extinction impairments were overcome by increasing the number of extinction trials (Experiment 2). However, a test of fear recall the next day showed persistent fear in the alcohol group across both viewpoints. Thus, alcohol impaired extinction rather than acquisition of fear, suggesting that extinction is more dependent than acquisition on alcohol-sensitive representations of spatial context. Overall, extinction learning under alcohol was slower, weaker and less context-specific, resulting in persistent fear at test that generalized to the extinction viewpoint. The selective effect on extinction suggests an effect of alcohol on prefrontal involvement, while the reduced context-specificity implicates the hippocampus. These findings have important implications for the use of alcohol by individuals with clinical anxiety disorders.

Investigating the interaction between schizotypy, divergent thinking and cannabis use.

Cannabis acutely increases schizotypy and chronic use is associated with elevated rates of psychosis. Creative individuals have higher levels of schizotypy, however links between cannabis use, schizotypy and creativity have not been investigated. We investigated the effects of cannabis smoked naturalistically on schizotypy and divergent thinking, a measure of creativity. One hundred and sixty cannabis users were tested on 1 day when sober and another day when intoxicated with cannabis. State and trait measures of both schizotypy and creativity were administered. Quartile splits compared those lowest (n=47) and highest (n=43) in trait creativity. Cannabis increased verbal fluency in low creatives to the same level as that of high creatives. Cannabis increased state psychosis-like symptoms in both groups and the high creativity group were significantly higher in trait schizotypy, but this does not appear to be linked to the verbal fluency change. Acute cannabis use increases divergent thinking as indexed by verbal fluency in low creatives.

Do AKT1, COMT and FAAH influence reports of acute cannabis intoxication experiences in patients with first episode psychosis, controls and young adult cannabis users?

Epidemiological and biological evidence support the association between heavy cannabis use and psychosis. However, it is unclear which cannabis users are susceptible to its psychotogenic effect. Therefore, understanding genetic factors contributing to this relationship might prove an important strategy to identify the mechanisms underlying cannabis-associated psychotic experiences. We aimed to determine how variation in AKT1, COMT and FAAH genotypes, and their interaction with three different groups (first episode psychosis (FEP) patients (n = 143), controls (n = 92) and young adult (YA) cannabis users n = 485)) influenced cannabis experiences, in those who had used cannabis at least once. We investigated the role of AKT1 (rs2494732), COMT Val158Met (rs4680) and FAAH (rs324420) on cannabis experiences by combining data from a large case-control study of FEP patients, with a naturalistic study of YA cannabis users (n = 720). Outcome measures were cannabis-induced psychotic-like experiences (cPLEs) and euphoric experiences (cEEs). We used linear mixed effects models to assess the effects of each genotype and their interaction with group, adjusting for age, sex, ethnicity, age of first cannabis use, years of use and frequency. cPLEs were more frequent in FEP patients than controls and YA cannabis users. cEEs were more prevalent in YA cannabis users than FEP patients or controls. Variation in AKT1, COMT or FAAH was not associated with cPLEs/cEEs. There was no interaction between genotype and group (FEP cases, controls and YA cannabis users) on cPLEs/cEEs. In conclusion, AKT1, COMT or FAAH did not modulate specific psychotomimetic response to cannabis and did not interact with group, contrary to previous research.

Treatment of generalised anxiety disorder with a short course of psychological therapy, combined with buspirone or placebo.

BACKGROUND: Very few studies have examined the combination of drug and psychological treatment in generalised anxiety disorder (GAD). Theoretically, buspirone should be a useful drug to combine with a learning-based therapy. METHODS: Sixty patients with GAD were randomly assigned to treatment with buspirone or placebo, combined with anxiety management training or non-directive therapy for a period of 8 weeks. RESULTS: Forty-four patients with a mean Hamilton Anxiety Scale score of 28 completed treatment. There were no significant differences between treatment groups. All groups showed significant improvement after 8 weeks compared to baseline. There were no baseline differences between those who completed the trial and those who did not but patients given buspirone were more likely to drop out. CONCLUSIONS: A short course of psychological therapy, whether or not accompanied by active medication, was an effective treatment for patients diagnosed as having quite severe symptoms of GAD. CLINICAL IMPLICATIONS AND LIMITATIONS: Dropouts led to a sample size which may have been too small to detect group differences. Cognitive therapy may have been more effective.

Acute effects of alcohol on the development of intrusive memories.

RATIONALE: Post-traumatic stress disorder is characterised by repeated intrusive imagery of the traumatic event. Despite alcohol's impairing effect on memory and frequent involvement in real-life trauma, virtually nothing is known of the interaction between alcohol and trauma memory. OBJECTIVE: We aimed to investigate the acute alcohol effects on spontaneous memories following a trauma film as well as explicit memory for the film. METHODS: Utilising an independent-group double-blind design, 48 healthy volunteers were randomly allocated to receive alcohol of 0.4 or 0.8 g/kg or a matched placebo drink. A stressful film was viewed post-drink. Skin conductance was monitored throughout and mood and dissociative symptoms were indexed. Volunteers recorded their spontaneous memories of the film daily in an online diary over the following week. Their explicit memory for both gist and details of the film was tested on day 7. RESULTS: Intriguingly, an inverted 'U' alcohol dose-response was observed on intrusive memories with a low dose of alcohol increasing memory intrusions while a high dose decreased intrusions. In contrast, explicit memory performance after 7 days showed a linear dose-response effect of alcohol with both recall and recognition decreasing as dose increased. CONCLUSIONS: These findings highlight a striking differential pattern of alcohol's effects on spontaneous memories as compared with explicit memories. Alcohol's effect on spontaneous memories may reflect a dose-dependent impairment of two separate memory systems integral to the processing of different aspects of a traumatic event.