BDNF promoter methylation and suicidal behavior in depressive patients

Introduction: Suicide is a major health problem, and depression is a major psychiatric cause of suicide. Suicide is influenced by the multifactorial interaction of many risk factors. Therefore, epigenetic research may lead to understandings that are applicable to suicide. This study investigated whether epigenetic changes are associated with suicidal behavior and evaluated the treatment outcome of suicidal ideation in depressive patients.

Methods: In 108 patients with major depression, the promoter methylation of the gene encoding brain-derived neurotrophic factor (BDNF) was measured. Sociodemographic and clinical characteristics including a history of previous depressive episodes, age at onset, duration of illnesses, family history of depression, and number of stressful life events as well as subjective perception of stress and assessment scales for depression (HAMD), anxiety (HAMA), function (SOFAS), disability (WHODAS-12), and quality of life (WHOQOL-BREF) were evaluated at baseline. Suicidal behavior was ascertained using a semistructured clinical interview with questions about severity and intent. Beck Scale for Suicide Ideation (BSS) was administered during 12 weeks of treatment with antidepressants.

Results: A higher BDNF promoter methylation status was significantly associated with a previous suicidal attempt history, suicidal ideation during treatment, and suicidal ideation at last evaluation as well as with higher BSS scores and poor treatment outcomes for suicidal ideation.

Limitations: Methylation status was investigated with limited area of the BDNF gene and sample size was relatively small.

Conclusions: BDNF methylation status could be a proxy marker for previous suicidal attempts and a clinical biomarker for poor treatment outcomes of suicidal ideation in depression.