(HealthDay News) — Variants of the stress-inducible neuropeptide and cotransmitter in serotonin and norepinephrine neurons, galanin, and its receptors confers increased risk of depression and anxiety among highly stressed individuals, according to a study published online March 24 in the Proceedings of the National Academy of Sciences.

Gabriella Juhasz, MD, PhD, from Semmelweis University in Budapest, Hungary, and colleagues examined the potential role of galanin in stress-related disorders in a cohort of 2,361 European, white adults from the United Kingdom and Hungary. Participants had experienced childhood adversity or recent negative life events.

The researchers found that, despite having disparate genomic loci, variants in genes for galanin and its receptors conferred increased risk of depression and anxiety in the study cohort. Galanin system genes had greater relevance in highly stressed individuals versus those with moderate or low life stress. Galanin system genes had a stronger effect than the well-studied 5-HTTLPR polymorphism in the serotonin transporter gene (SLC6A4). The galanin gene-life stressors interaction explained more of the variance (1.7%; P=0.005) compared with the life stress-only model in conventional multivariate analysis. This effect was replicated in subpopulations from the United Kingdom and Hungary and in males and females.

“The results suggest that the galanin pathway plays an important role in the pathogenesis of depression in humans by increasing the vulnerability to early and recent psychosocial stress,” the authors write. “Correcting abnormal galanin function in depression could prove to be a novel target for drug development.”

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