The genetics of psychotic bipolar disorder

Abstract

Psychotic features, defined as delusions or hallucinations, commonly occur in bipolar disorder (BP) and may be indicative of a more homogeneous form of the illness, with possible etiologic ties to schizophrenia. Several studies have shown that psychotic features aggregate in bipolar families, and increased interest in the molecular genetics of psychotic BP is emerging. Although preliminary, linkage studies of psychotic BP show replicated evidence for suggestive genome-wide linkage to chromosomes 8p and 13q, which have been implicated in prior linkage studies of schizophrenia and BP. Association studies of psychotic BP and subtypes such as mood-incongruent psychotic BP have uncovered modest positive results for several candidate schizophrenia susceptibility genes, including dysbindin, DAOA/G30, Disrupted-in-Schizophrenia-1, and neuregulin 1. These tentative results are consistent with the hypothesis that the subphenotype of psychotic BP may represent a clinical manifestation of "overlap" genes between schizophrenia and mood disorder syndromes.

Glia and immune cell signaling in bipolar disorder: insights from neuropharmacology and molecular imaging to clinical application

“…74 Several studies utilizing the Global Assessment of Functioning Scale, which captures both social-occupational and interpersonal functioning, identified unemployment and functional impairment as the most highly familial features of BD among 40 variables tested. 67,75 The association of PPARD gene with poor functioning is consistent with a potential role for Wnt dysfunction in moderate to severe BD. Taken together, these findings suggest that Wnt polymorphisms may confer vulnerability for developing BD, and may act through inflammatory cascades to regulate trophic support to brain structures.…”

New Ways to Classify Bipolar Disorders: Going from Categorical Groups to Symptom Clusters or Dimensions

“…Atypical antipsychotics may be intuitively more appropriate. From a research point of view, psychotic symptoms could shed some light on common genetic and/or environmental factors between bipolar disorders and schizophrenia [17,18].…”

Corpus callosum area in patients with bipolar disorder with and without psychotic features: an international multicentre study

“…[18][19][20] In a recent study, we reported that BD with psychosis was associated with greater microstructural CC impairments than BD without a history of psychosis. 3 However, to our knowledge only 2 studies have directly compared callosal areas between these 2 subgroups, yielding negative results.…”