Emotional processing and bipolar disorder

Thesis

The aetiology of bipolar disorder remains unclear and investigation to date has focussed largely on bipolar patients. Whilst ultimately of huge value, such studies may also be confounded by current mood or experience of repeated illness episodes or current or past medication; using at-risk samples may bypass some of these problems. The current research therefore assessed the efficacy of the Mood Disorder Questionnaire (MDQ) as a screening tool for vulnerability to bipolar disorder. The MDQ was used with two sets of criteria to identify two sub-groups of medication-naïve young bipolar phenotype subjects who were at risk for bipolar disorder by virtue of experience of mood elevation. Analysis of data from the Student Stress Survey was carried out to characterise the bipolar phenotype. Compared to a control group with no experience of mood elevation, the two bipolar phenotype sub-groups showed a gradient of prevalence of bipolar diagnosis and associated co-morbidity. Behavioural and functional magnetic resonance imaging (fMRI) techniques were employed to investigate emotional processing, decision-making, and sleep and circadian rhythmicity in bipolar phenotype students. Analyses revealed that positive emotional processing biases, disrupted decision-making, and increased activity during sleep were associated with the bipolar phenotype and, therefore, may represent vulnerability markers for bipolar disorder. Finally, a psychopharmacological investigation of quetiapine, which stabilises mood, was carried out in healthy volunteers. One-week quetiapine administration resulted in biases away from both positive and negative emotional stimuli (i.e. a mood-stabilising effect), reduced discrimination between different magnitudes of gains and losses during risky decision-making (consistent with an antidepressant effect), and increased sleep duration. In sum, this research has developed our understanding of vulnerability markers associated with the bipolar phenotype and provided a first step towards uncovering the psychological mechanisms through which quetiapine’s clinical effects may be mediated.

Authors: Rock, P

• Publication date: 2010
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: Oxford University, UK
• Language: English
• Keywords: bipolar disorder; quetiapine; mood disorder questionnaire; circadian rhythm; emotion processing; bipolar spectrum; sleep
• Subjects: Bipolar disorder; Psychiatry; Neuroscience