Explanatory style and depression : the role of activity : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology at Massey University, Albany, New Zealand

Abstract

Learned helplessness theory and its subsequent reformulation propose that a pessimistic explanatory style renders an individual vulnerable to depression. A large body of literature has supported this association within various samples and utilising a range of methodologies. No prior study has explored explanatory style and depression among a New Zealand sample of clinically depressed adults. Furthermore, no prior research has examined the role of activity level or activity type in relation to these variables. Given the importance of behavioural activation in recovery from depression, Study 1 aimed to bridge this gap. The sample consisted of 29 adult clients diagnosed with Major Depressive Disorder (MDD) and receiving a 20 session protocol of Cognitive Behaviour Therapy (CBT) as part of The Depression Study; a treatment outcome study conducted at Massey University, Albany, Auckland, New Zealand. Data were derived from intake assessment scores for explanatory style and depression severity, as measured via the Attributional Style Questionnaire (ASQ) and Beck Depression Inventory–Second Edition (BDI-II) respectively. Data were also derived from several activity level and activity type indices formulated for Study 1 by the use of information contained within activity charts; a tool used for a between-session task (homework) conducted early in CBT. Study 1 supported an association between a pessimistic explanatory style and depression severity and provisional support was found for the proposed model of the current project, implicating the role of activity among interactions between explanatory style and depression. In collecting data for Study 1 it became apparent that an adaptation to the activity chart may yield greater information particularly with regard to activity type, such as the extent to which social interaction occurred. Study 2 of the current research project aimed to compare the original activity chart with the adapted chart, by grouping The Depression Study clients according to whether they completed the original (n = 15) or the adapted (n = 8) activity chart, and comparing the data obtained. Mann-Whitney U tests confirmed that the adapted chart was more successful in collecting information regarding social interaction and ratings for mastery and pleasure. It is suggested that the adapted chart could be more beneficial in contrast to the chart typically used in CBT to date; this advantage could extend across both research and clinical settings for the examination of client activity.