Background: Few studies have assessed adherence to the Mediterranean diet in relation to psychological health, in particular in the Middle East.

Objective: To examine the association between adherence to Mediterranean dietary pattern and prevalence of psychological disorders among a large population of Iranian adults.

Design: In this cross-sectional study on 3172 Iranian adults aged 18–55 years, we used a validated food frequency questionnaire for the assessment of dietary intakes. Adherence to the Mediterranean dietary pattern was examined using the Trichopoulou et al. method. To assess psychological health, the Iranian validated version of the Hospital Anxiety and Depression Scale (HADS) was used. Psychological distress was assessed through the use of General Health Questionnaire (GHQ).

Results: Mean age of study participants was 36.54 � 4.97 years. After controlling for potential confounders, participants with the greatest adherence to the Mediterranean diet had lower odds for depression (OR: 0.60, 95% CI: 0.46–0.78), anxiety (OR: 0.61, 95% CI: 0.42–0.86) and psychological distress (OR: 0.60, 95% CI: 0.45–0.79) compared with those with the lowest adherence. When the association with components of Mediterranean diet was examined, we found that high intake of fruits and vegetables was associated with a lower odds of depression, anxiety and psychological distress. In contrast, high intake of grains was positively associated with depression, anxiety and psychological distress.

Conclusion: We found evidence indicating an inverse association between adherence to Mediterranean dietary pattern and odds of psychological disorders including depression, anxiety and psychological distress.