Neuropsychological profiles of people receiving cognitive behaviour therapy for co-occurring depression and alcohol misuse

Research Doctorate - Doctor of Philosophy (PhD)The co-occurrence of depression and alcohol misuse happens at rates greater than chance and results in a clinical presentation that is more difficult, time consuming, and costly to treat than when either condition occurs in isolation. Traditionally, depression and alcohol use disorders have been treated separately by specialist services which focus on mental health or substance abuse problems. It is increasingly clear however, that the co-occurrence of depression and alcohol misuse requires specific treatment strategies designed to address both problem areas. The broad aim of this thesis was to investigate psychological treatment options for people with co-occurring alcohol misuse and depression. Specifically an integrated approach which assists the client to draw connections between their two problem areas was compared to single-focused interventions in the short- and long-term in Paper 1 and Paper 2 respectively. The relevance of individual factors, such as cognitive functioning, to treatment response in people with co-occurring alcohol misuse and depression was also explored. People with either one of these conditions have been shown to experience cognitive impairments, particularly in the domains of memory and executive functioning, yet little is known about the cognitive impact of their co-occurrence. Paper 4 presents a systematic review of the published cross-sectional descriptions of neuropsychological test performance of this group. The review aimed to describe the cognitive profile of people with this comorbidity and identify any gaps in the literature. Paper 3 and Paper 5 describe the neuropsychological test performance of people with co-occurring alcohol misuse and depression, and identified the cognitive functions which might predict early and post-treatment change in depressive symptoms and alcohol misuse. Paper 6 describes the long-term neuropsychological follow-up of the sample described in Paper 3 and Paper 5. The study aimed to describe the pattern of cognitive recovery in the context of reduction in depressive symptoms and alcohol use, and also to identify any predictors of cognitive improvement. The final chapter of this thesis synthesises the main findings of the preceding six chapters and draws together the clinical implications to formulate psychological assessment and treatment recommendations for people with co-occurring alcohol misuse and depression. The findings of this thesis suggest that people with these co-occurring conditions can and do benefit from evidence based psychological interventions such as motivational interviewing and cognitive behaviour therapy. Furthermore, despite their hazardous use of alcohol and depressive symptoms, they appeared to be functioning in the average range cognitively. Indeed any impairment was not sufficient to preclude use of psychological treatment strategies. Taken together, the results of this research add to the accumulated body of knowledge in this area and support the use of psychological interventions to address both depression and alcohol misuse in people with these highly prevalent and damaging problems