Neurotransmitter and neuromodulator genes associated with a history of depressive symptoms in individuals with alcohol dependence.
BACKGROUND
Depressive symptoms are common among individuals with alcohol use disorders and impact treatment outcome. Substantial overlap exists among the neurobiological systems proposed in the pathophysiology of depressive and alcohol use disorders; however, specific genetic effects contributing to risk for depressive comorbidity remain poorly understood.


METHODS
This study examines the association of depressive symptom scores for lifetime depression (the sum of DSM-IV major depression co-endorsed criteria for lifetime depression) with markers in 120 candidate genes in 554 alcohol-dependent individuals. The candidate genes code for molecules involved in dopamine, serotonin, glutamate, gamma-aminobutyric acid (GABA), and opioid neurotransmission, cell signaling, pharmacokinetics, stress biology, and behavioral control. Analyses were conducted at the single marker level with experimentwise permutation to control for multiple testing.


RESULTS
Results revealed nominal associations for markers in 20 genes. Following experimentwise permutation, markers in the corticotropin-releasing hormone-binding protein (CRHBP) the μ-opioid receptor (OPRM1) and the β1 subunit of GABA A (GABA(A)) receptors (GABRB1) met or exceeded the significance threshold. None of the markers associated with depressive symptom scores were significantly associated with alcohol dependence symptom scores.


CONCLUSION
These findings suggest potential risk genes for depressive symptoms in alcohol-dependent individuals.