BACKGROUND: Suicide is a major cause of death throughout the world. Approximately 60% of all suicides have a history of depression. Previous studies of structural brain imaging have shown that suicide is often associated with abnormal fronto-limbic networks. However, the mechanism underlying suicide in depression remains poorly understood.
METHOD: Twenty sex- and age-matched suicidal unipolar patients were compared with 18 non-suicidal unipolar patients and 28 healthy controls. High-resolution T1-weighted 3T magnetic resonance imaging (MRI) scans were acquired. Hamilton Depressive Rating Scale (HAMD) and Self-Rating Depression scale (SDS) were evaluated. The criterion for suicidality was one or more documented lifetime suicide attempts. A whole-brain optimized voxel-based morphometry (VBM) approach was applied. The Dysfunctional Attitude Scale (DAS) was used to measure cognitive scheme in depressive patients.
RESULTS: Compared with controls, patients without suicide history showed significant decreased gray matter volume in the left insula lobe [-35 18 9], whereas patients with suicide history showed significantly decreased gray matter volume in the right middle temporal gyrus [60 -53 -8] and increased gray matter volume in the right parietal lobe [39 -39 60]. Compared with the non-suicidal depressed patient group, the suicidal group showed significant decreased gray matter volume in left limbic cingulated gyrus [-2 -21 28]. Moreover, the gray matter volume values in this significantly different brain region were negatively correlated with dysfunctional attitude scores in suicidal depressed patients. LIMITATIONS: This study needs replication and further clarification in a larger patient population.
CONCLUSIONS: Suicide attempts in young depressed patients may be related to abnormal gray matter volumes in temporal-parietal-limbic networks. Specifically, small left limbic cingulate gyrus volumes may be a candidate for the prediction of suicide in young depressed patients.