Premorbid and postmorbid correlates of global neurocognitive dysfunction in bipolar disorder

The aim of this exploratory study was to evaluate neurodevelopmental abnormalities, clinical course, and functional outcome in patients with bipolar disorder with and without global neurocognitive deficits.

Ninety-four euthymic patients were consecutively enrolled. Based on baseline neurocognitive assessment, they were categorized as having (BD-GD: 30.9%) or not having (BD-CG: 69.1%) global neurocognitive deficits. Neurodevelopmental abnormalities (history of obstetric complications, premorbid IQ, premorbid adjustment, and soft neurological signs) were addressed in both patient groups. After baseline assessment, they were followed prospectively for 24 months to assess clinical course (using the mood chart method) and functional outcome.

Patients with BD-GD had worse premorbid adjustment during childhood and adolescence and more neurological signs than those with BD-CG. Furthermore, there was a trend toward a greater history of obstetric complications and a lower premorbid IQ in the BD-GD group. During the follow-up period, patients with BD-GD experienced longer periods of (hypo)manic symptoms, more mood swings, and worse functional outcome than patients with BD-CG.

The results of this study support the existence of a subgroup of patients with bipolar disorder who may have neurodevelopmental abnormalities, global neurocognitive dysfunction, and a worse clinical course and functional outcome. Neurodevelopmental abnormalities might contribute to understanding the heterogeneity of clinical features and functional outcome among patients with bipolar disorder.