Theories of emotion see affective processes as important in guiding behaviour, and social/cognitive theories have implicated cognitive appraisals in a motivational context. The control-value theory combines these approaches, predicting that high levels of expectancy and control lead to associated levels of anticipatory affect in those approaching a goal. This theory, combined with literature on approach motivation in depression, led to the proposed model of the effect of depression on behavioural striving, and subsequent levels of depression. The current study aimed to test this model. Sixty participants completed measures of depression, approach-related affect, cognitive appraisals and striving behaviour in relation to their own personal goals, with follow-up measures of depression and striving behaviour completed two weeks later. They also participated in an experimental manipulation of approach-related cognitive appraisals. The model received mixed support, with strongest evidence for the proposed pathway from depression to anticipatory affect via cognitive appraisals, especially for those who were at least mildly depressed. However contrary to the model, depression was not found to be associated to striving, and no variables other than depression predicted future depression. The study was conducted with a non-clinical population, there was reduced power at follow-up, and the experimental manipulation may have been unsuccessful. This study provided preliminary support for the new model, and although findings were mixed, future research may be more conclusive. Findings suggest that therapy specifically tapping into approach-related cognitive appraisals, as well as approach-related affect, may be therapeutically beneficial in working with depression.

Background: Research into the benefits of exercise for individuals with Bipolar Disorder (BD) is limited and no current guidelines exist around recommending exercise during a hypomanic/manic state. The Behavioural Activation System (BAS) dysregulation theory is a popular model that attempts to explain the link between approach motivation (AM) and the difficulties that individuals with BD experience. It may offer an explanation for the ‘upward spiral’ reported by individuals with a diagnosis of BD in response to certain types and intensities of exercise. This study looked to investigate the impact of different intensities of exercise on the maintenance of AM levels. The presence of hypomanic traits and how these interacted between AM and exercise was also of interest. Method: Participants filled out an online pre-screening questionnaire identifying hypomanic traits. 61 then completed a computer task designed to induce higher levels of AM before taking part in one of three 15 minute activities (sedentary, moderate exercise or vigorous exercise). Various measures linked to hypomanic symptoms were taken during testing. Results The main findings indicated that vigorous exercise significantly increased individuals AM levels in comparison to moderate or no exercise. This relationship was not however found to be moderated by the presence of hypomanic traits. Conclusions: Vigorous exercise seems to have a greater impact on AM levels regardless of an individual’s levels of hypomanic traits. This has implications in terms of the type of exercise should engage in when experiencing hypomania. Any recommendations however within this study should be taken in light of the limitations identified. Further research replicating these results with a larger sample or using a BD population are recommended.

It is well established that methadone maintenance (MM) reduces but does not eliminate the self-administration of other illicit drugs. For those on MM, there is considerable variation in consumption patterns, route of heroin administration, additional non-opioid substances routinely administered and the clinical disorders associated with these patterns of use. While there is a large literature base documenting these phenomena, studies have been almost exclusively descriptive in nature, with little attempt to develop a theoretical model in which to understand such use. In the following thesis, a model proposed by Gray was tested, the Reinforcement Sensitivity Theory (RST). This biopsychosocial model broadly describes two action tendencies; approach (Behavioural Activation System) and avoidance or withdrawal (Flight Fight Freeze System and the Behavioural Inhibition System). The model proposes that a heightened sensitivity to punishment underlies anxiety disorders. Conversely, a heightened sensitivity to rewarding stimuli may predispose some individuals to engage in highly rewarding behaviour and is associated with conduct disorder and antisocial personality disorder. According to the Joint Subsystems Hypothesis, these personality styles are mutually dependent, whereby BIS and BAS interact to influence reward mediated and punishment mediated behaviours. Based on Gray's model, this thesis tests whether opiate dependent individuals with heightened sensitivity to punishment are more likely to use anxiolytic drugs (such as benzodiazepines), and individuals with heightened reward sensitivity will show a preference for substances that have high reward potential (such as stimulants). At time one, the participant sample (N= 120) comprised 71 males (59%) and 49 females who were opioid dependent and recruitment took place over an eight-month period in two city opioid replacement clinics. A range of measures was administered to assess substance use, mood, anxiety and the personality dimensions of reward sensitivity and punishment sensitivity, with substance use again measured at three months. Results of the first study suggested that a large proportion of the variance was accounted for by personality within the models. A total of 98 participants (81%) participated in the 12-week follow-up study. Sensitivity to punishment and reward significantly predicted drug preference. Although psychopathology symptoms were not able to moderate the relationship between personality and drug use, anxiety symptoms negatively mediated the relationship between punishment sensitivity and anxiolytic use, whereby the relationship became non-significant. In contrast, sensitivity to reward remained the strongest predictor of amphetamine use over antisocial characteristics. Individual differences were not able to predict treatment retention nor susceptibility to relapse during a 12-week initiation to a MM programme.