CHILDREN OF PARENTS DIAGNOSED WITH BIPOLAR DISORDER: AN INVESTIGATION OF THE BEHAVIOURAL, STRUCTURAL AND FUNCTIONAL CORRELATES OF RISK

Abstract

Emotion processing and regulatory deficits have been well established in individuals diagnosed with bipolar disorder (BD). Both structural and functional neural deficits have been associated with the presence of psychiatric symptoms in BD. In Chapter 2, we reviewed cortical thickness deficits found in patients with BD. It is unclear however, how early these deficits appear; whether they contribute to risk, or whether these deficits develop as a consequence of the onset of symptoms.

To address this, many researchers have turned to high-risk offspring populations. These high-risk offspring are at much greater risk of developing BD by virtue of having a parent diagnosed with BD. Moreover, the presence of anxiety, depression or ADHD related symptoms in this population suggest these children are at even greater risk to develop BD. By comparing high-risk offspring with and without the symptoms can help to elicudate neural correlates associated with risk and resilience for BD. It was the aim of this thesis research to investigate the behavioural, structural and functional correlates of risk. Specifically, presented in this thesis, we compared the gray matter integrity, through volume (Chapter 3) and cortical thickness (Chapter 4) techniques, in symptomatic and asymptomatic high-risk offspring to healthy children of healthy parents. We also compared the ability of these offspring to perform an emotion-labelling task (Chapter 5) and engage in emotional conflict monitoring and conflict adaptation during an fMRI scan (Chapter 6).

Altogether, our results provide evidence for the presence of gray matter volume, emotion labelling, and conflict monitoring and conflict adaptation functional deficits in high-risk offspring compared to healthy children of healthy parents. With the exception of cortical thickness, we found that the deficits between symptomatic and asymptomatic high-risk offspring were comparable. This suggests that behavioural, structural and functional deficits may reflect neural correlates of risk and are not associated with the presence of symptoms.