Late-Life Bipolar Disorder Subtypes According to Age Onset

Abstract: This article characterizes the clinical differences between bipolar disorder (BD) subtypes in 44 early-onset (EOBD), 32 late-onset (LOBD), and 30 very-late-onset (VLOBD) disorders. We considered vascular mania in five LOBD and 17 VLOBD, with an association with right-sided lesions for VLOBD. Other nonvascular-related brain injuries preceded the emergence of mania: traumatic brain injury (one LOBD, two VLOBD), epilepsy/brain tumor (one LOBD), multiple sclerosis (one LOBD), and HIV-encephalopathy/cerebral toxoplasmosis (two VLOBD). No secondary mania was identified in 21.4% of the VLOBD and 64% of the LOBDd, corresponding to presumptive idiopathic/primary BD. A transdiagnostic conversion within the affective disorder spectrum occurred in 50% of the VLOBD, 30.8% of the LOBD, and 20.5% of the EOBD across the lifespan. An interplay between genetics and age-specific processes may underlie the neurobiological underpinnings of late-life-onset idiopathic/primary BD.