Structural brain changes in first episode mania with and without psychosis: Data from the Systematic Treatment...

Area of Science:

• Neuroimaging
• Psychiatry
• Neurobiology

Background:

• The neurobiological basis of bipolar I disorder remains unclear, with prior structural neuroimaging studies yielding inconsistent findings.
• Hypothesized that specific clinical subtypes of bipolar I disorder, particularly those with mood-incongruent psychotic features, may exhibit more pronounced structural brain alterations.

Purpose of the Study:

• To investigate structural brain differences in patients experiencing first-episode mania, categorized by the presence and type of psychotic symptoms (mood-congruent vs. mood-incongruent) or absence of psychosis.
• To compare these findings with those of healthy control subjects.

Main Methods:

• Structural magnetic resonance imaging (MRI) was used to assess brain volumes in patients with first-episode mania and healthy controls.
• Patients were subgrouped based on mood-congruent psychosis (n=16), mood-incongruent psychosis (n=32), or no psychosis (n=7).

Main Results:

• Patients with mood-incongruent psychosis exhibited significantly reduced total intracranial volume and increased cerebrospinal fluid (CSF) volume compared to controls.
• Patients with mood-congruent psychosis showed reduced total white matter volume and increased CSF volume.
• Both psychotic groups displayed significant volume reductions in anterior cingulate and medial prefrontal cortices. Mood-incongruent psychosis was specifically associated with reduced volume in the left middle temporal gyrus, right inferior parietal gyrus, right fusiform gyrus, left middle orbitofrontal gyrus, and cerebellum.

Conclusions:

• Preliminary findings suggest that the presence and specific type of psychosis in first-episode mania may serve as phenotypic markers for distinct biological variations within bipolar disorder.
• These structural brain alterations highlight potential neurobiological distinctions between different psychotic presentations of bipolar I disorder.