Recognition of dynamic facial affect in substitute maintained opiate users

This thesis investigates the capacity to identify Emotional Facial Expressions (EFE) in people who have a history of using illicit substances. Part one is a systematic literature review that critically appraises the available research in this area. The studies reviewed investigate the acute, sub-acute and/or chronic effects of different levels of use of opiates, cannabis, MDMA, cocaine, methamphetamine, and multiple substances. Methodological constraints in this area of research make synthesis and interpretation of findings problematic. Despite this, the review highlights evidence of deficits in EFE recognition associated with substance use. These appear more marked for negative emotions, particularly fear and disgust. Part two is an empirical study that aims to investigate EFE recognition in opiate users. Substitute prescribed opiate users are compared with controls on performance on a dynamic EFE recognition task. The findings of this study suggest that there is a general deficit in sensitivity to EFEs in opiate uses and specific deficits in the recognition of neutral disgust and fear expressions. Part three is a critical appraisal focusing on the process of carrying out research with clinical populations and within substance use in particular. This considers the difficulties and benefits of integrating clinical practice and empirical research in the role of clinical psychologists.