This article summarizes the main discussions at a meeting on the biological, social and clinical bases of drug addiction focused on contemporary topics in drug dependence. Four main domains are surveyed, reflecting the structure of the meeting: psychological and pharmacological factors; neurobiological substrates; risk factors (including a consideration of vulnerability from an environmental and genetic perspective); and clinical treatment. Among the topics discussed were tolerance, sensitization, withdrawal, craving and relapse; mechanisms of reinforcing actions of drugs at the behavioural, cognitive and neural levels; the role of subjective factors in drug dependence; approaches to the behavioural and molecular genetics of drug dependence; the use of functional neuroimaging; pharmaceutical and psychosocial strategies for treatment; epidemiological and sociological aspects of drug dependence. The survey takes into account the considerable disagreements and controversies arising from the discussions, but also reaches a degree of consensus in certain areas.

The clinical effectiveness of cue exposure (CE) treatment in alcohol dependence was evaluated in a controlled trial. Thirty-five men who were detoxified and severely alcohol dependent received either CE or relaxation control (RC) treatment. CE Ss had 400 min exposure to the sight and smell of preferred drinks over 10 days in a laboratory setting. RC Ss spent identical time in the laboratory but had relaxation therapy and only 20 min exposure to alcohol cues. During 6-month follow-up, personal interview was achieved with 91% of Ss. CE Ss had a more favorable outcome than the RC Ss in terms of latency (length of time) to relapse of heavy drinking (p < .01) and total alcohol consumption (p < .05). Significant predictors of latency to heavy drinking and dependence included skin conductance level (p < .001) and experimental condition (p < .01). Results point to the potential importance of cue exposure as a treatment for addictive behavior.

Participants saw a series of situations in which a cue (a light appearing at a certain position) could be followed by an outcome (a drawing of a tank that exploded) and were afterwards asked to rate the likelihood of the outcome in the presence of the cue. In Experiments 1 and 2, the compound cues AT and KL were always followed by the outcome (AT+, KL+). During an elemental phase that either preceded or followed the compound phase, Cue A was also paired with the outcome (A+). Cue T elicited a lower rating than Cues K and L when cues were described as being weapons but not when the cues were said to be indicators. The magnitude of this blocking effect was also influenced by whether the outcome occurred to a maximal or submaximal extent. Experiment 3 replicated the effect of cue instructions on blocking (A+, AT+) but showed that cue instructions had no impact on reduced overshadowing (B-, BT+). The results shed new light on previous findings and support probabilistic contrast models of human contingency judgements.

A review of the literature pertinent to cue exposure treatment in alcohol dependence is presented. Psychological models of relapse, based on conditioning and social learning theories, are critically evaluated. In particular, attention is drawn to the potential implications for cue exposure research and treatment of an interaction between Pavlovian and operant conditioning, problems with the application of the concepts of arousal and craving and the importance of a systems model to understand physiological responses. It is concluded that no study has so far demonstrated a link between conditioned responses to alcohol-related cues and relapse, an assumption on which cue exposure treatment is based. Further, the evidence for the effectiveness of cue exposure as a treatment is lacking. Promising research directions are identified.

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