Stress, Perseverative Cognition and Health Behaviours

Perseverative cognition (PC) is the repeated activation of stress-related cognitions (including worry and rumination). The Perseverative Cognition Hypothesis (PCH)
posits that, in the same way as stress, PC damages health via its ensuing physiological activation. The central proposal of this thesis is that, like stress, PC may influence health via an indirect, behavioural pathway, termed the Extended PCH (EPCH). The principal aim was therefore to investigate the association between PC and health behaviours (HBs) and to investigate how PC interacts with stress in predicting HBs. Meta-analyses of 19 studies suggested an association between PC and increased health-risk behaviours (Chapter 2), and between PC and poorer sleep across 55 studies (Chapter 3). Associations between stress, PC and HBs were assessed via
survey (Chapter 4). Associations emerged between worry and rumination (brooding and reflection) and some health-risk behaviours, cross-sectionally and prospectively. Brooding predicted more snacking at low-medium stress levels, but there was no relationship during high stress. A diary study (Chapter 5) revealed that components of PC predict both health-risk and health-promoting behaviours and interact with daily hassles to contribute to HBs, including unhealthy snacking, sleep and physical activity. Partial support was found for the EPCH. PC predicts some detrimental HBs but there were some contradictory findings and associations differed across types of PC (worry, brooding, reflection, state vs trait) and HBs and across measurement timeframes for stress and HBs. Therefore, the model may be more complex than
originally conceptualised. There are remaining questions pertaining to the EPCH. Primarily, future research should (1) test causation, (2) assess bi-directional
associations between PC and HBs, (3) improve measurement specificity of PC and, (4) test PC interventions on HBs. This thesis provides a testable theoretical framework in which to assess associations between stress, PC and HBs and contributes to our understanding of these associations.