Bipolar Affective Disorder: The Striatal Morphological Correlates

Abstract

Background: Strong evidence is emerging that implicates corticobasal ganglia circuit abnormalities in the expression of affective illnesses, such as bipolar affective disorder (BAD). The striatum (comprising caudate, putamen and nucleus accumbens) has been shown to be reduced in size in younger patients with BAD, and we wish to explore this in an older cohort. Objectives: We aim to refine our understanding of the relationship between striatal morphology and the progression and features of BAD in older persons. Methods: We are conducting a case–control study in an older population (>45 years) utilising brain magnetic resonance imaging (MRI) scans and clinical data in patients with BAD (N = 18) and healthy controls (N = 21). Using the ANALYZE (Analyze Direct Inc.) software system and spherical harmonic (SPHARM) software, we will measure the volume and shape of the caudate and the putamen. We will analyse striatal morphology and bipolar status both between groups and within groups for clinical features of neuropsychiatric dysfunction. Findings: We expect that striatal volume will be reduced in patients with BAD compared to controls and that within groups volume will be correlated with the severity of neuropsychological dysfunction. Conclusions: This project will elucidate brain structural– functional correlations of BAD