Altered Volumes of the Amygdala and Hippocampus in the Brain of Suicidal Patients with First Episode Schizophrenia.

Abstract

Suicide remains a significant cause of premature death in schizophrenia patients. Structural alterations in the brain and neurobiological mechanisms behind suicidal behavior (SB) in first-episode schizophrenia (FES) have received increasing attention. The amygdala and hippocampus regulate behaviors such as risk-taking, impulsivity, and emotional processing. Abnormalities in these regions have been linked with suicidal ideation, behavior, and psychotic symptoms. However, the association remains unclear. The study included 20 FES patients with current SB, 51 FES patients without SB, and 42 healthy controls. All patients were subjected to clinical evaluations to assess psychotic symptoms and suicidal ideation and behavior, both current and lifetime. T1-weighted magnetic resonance imaging scans were processed through two web-based automatic analysis tools, MRICloud, and volBrain. Bilateral amygdala volumes were found to be significantly lower in the patient groups, while schizophrenia and suicidal ideation had opposite effects on amygdala volumes. Hippocampal subfields such as the right Cornu Amnonis (CA) fields varied according to the clinical status of the patients, including the severity of suicidal ideation and behavior. These findings support not only the involvement of the amygdala and hippocampus in SB and schizophrenia but also their roles in the discrimination of SB in patients with schizophrenia.