Increased DNA methylation in the suicide brain.

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• Childhood adversity and adult stress increase risks for major depression and suicide.
• Genetic and epigenetic factors are implicated in predispositions to major depression and suicide.

Purpose of the Study:

• To investigate DNA methylation signatures in the brains of individuals who died by suicide with a diagnosis of major depressive disorder.
• To compare DNA methylation levels between suicides and non-psychiatric controls.

Main Methods:

• Postmortem brain tissue (ventral prefrontal cortex) from 53 suicides and non-psychiatric controls (aged 16-89 years) was analyzed.
• DNA methylation levels were determined at single C-phosphate-G (CpG) resolution sites.

Main Results:

• DNA methylation levels increase throughout the lifespan.
• Suicides exhibited an 8-fold greater number of methylated CpG sites compared to controls.
• These methylation changes in suicides exceeded those observed in normal aging.

Conclusions:

• Increased DNA methylation in the brain is associated with suicide in the context of major depressive disorder.
• Elevated DNA methylation may contribute to the neuropathology and psychopathology underlying suicide risk in depression.