Relationship between dietary patterns and depressive symptoms: difference by gender, and unipolar and bipolar...

Although several studies have reported associations of depressive state with specific nutrients and foods, few have examined the associations with dietary patterns in adults. We investigated the association between major dietary patterns and depressive symptoms in Japanese patients with depression. Subjects were 166 Japanese patients (104 men and 62 women), aged 22-74 y, who were treated at a hospital psychiatry clinic in Tokyo. Depressive symptoms were assessed using the Himorogi Self-rating Depression Scale (H-SDS) and Himorogi Self-rating Anxiety Scale (H-SAS). We categorized depressive symptoms into 3 types: physical, psychiatric, and anxiety symptoms. Dietary patterns were derived using principal component analysis of the consumption of 59 food and beverage items, which was assessed by a validated brief diet history questionnaire. Three dietary patterns were identified: 1) "plant foods and fish products," 2) "fish," and 3) "Western/meat." We calculated the correlation coefficients for the relationship between each dietary pattern score and depressive symptom score in unipolar depression vs. bipolar depression and in men vs. women. In bipolar depression, the plant foods and fish products pattern showed an inverse relationship with physical and psychiatric symptoms, and in men, this pattern showed an inverse relationship with psychiatric symptoms. The fish pattern and Western/meat pattern were not significantly associated with the 3 types of depressive symptoms. In conclusion, we identified 3 dietary patterns and found that associations between these patterns and depressive symptoms were observed only in bipolar depression and only in men.