Manganese accentuates adverse mental health effects associated with alcohol use disorders

Background: A population-based study on early neurotoxic effects of environmental exposure to manganese (Mn) enabled us to investigate the relation between blood Mn levels (MnB), alcohol consumption, and risk for alcohol use disorders (AUD) on mental health. Methods: Participants were selected using a random stratified sampling procedure. Self-administered questionnaires provided data on alcohol consumption, sociodemographics, medical history, and lifestyle. Mood states were assessed with the Brief Symptom Inventory (BSI), and risk for AUD was surveyed using a behavioral screening questionnaire and categorized into no, low, and high risk. Of 297 participants, 253 current drinkers who had responded to all questions on alcohol use were retained. Results: Psychologic distress increased with risk for AUD and alcohol consumption ≥ 420 g/week. Higher MnB levels (≥7.5 μg/L) intensified the relation between risk for AUD and BSI scale scores. The Prevalence odd ratios for positive cases of psychologic distress with risk for AUD, 1.98 [1.13–3.46], differed when divided by MnB strata: lower MnB: 1.34 [0.64–2.85]; higher MnB: 4.22 [1.65–10.77]. Conclusions: These findings suggest that higher levels of blood manganese significantly increase neuropsychiatric symptoms associated with risk for alcohol use disorders.