High Frequency and Intensity of Drinking may Attenuate Increased Inflammatory Cytokine Levels of Major Depression in Alcohol-use Disorders

Aims: As major depression (MD) is often comorbid with alcohol-use disorders (AUD) and alcohol itself modulates the immune system, we examined serum levels of interleukin (IL)-6, IL-10, tumor necrosis factor (TNF), and interferon (IFN)-gamma in AUD patients with and without MD. Putative interactions between alcohol variables and MD on cytokine levels were also assessed. Methods: A consecutive sample of inpatients with AUD (N = 176) from eight alcohol treatment centers in Kathmandu, Nepal, was assessed for alcohol use and depression by administering fully structured psychiatric interviews. Serum cytokine levels were determined using multiplex technology. Results: Alcohol-use disorders patients with a positive history of MD had higher levels of the inflammatory cytokines IL-6 (P = 0.019), TNF (P = 0.020), and IFN-gamma (P = 0.001), but not of IL-10 (P = 0.853). AUD patients with MD had higher concentrations of cytokines compared with those without, regardless of the severity of the alcohol problem, but the difference was greater among those drinking in lower frequency and intensity. Conclusion: These findings provide evidence for altered functioning of the immune system in AUD patients with comorbid MD. However, frequent and intense drinking may attenuate the difference in the cytokine profiles between AUD patients with and without MD.