Prevalence and Comorbidity of Anxiety and Depressive Disorders in Studies of PRIME-MD and PHQ (Patient Health Questionnaire) in Japan

We examine two studies on the prevalence and comorbidity of anxiety and depressive disorders in Japanese patients in primary care settings. The PRIME-MD study (Primary Care Evaluation of Mental Disorders) in Japan was conducted in seven primary care sites. The sample group included 601 adult patients (249 males, 352 females, mean age = 58.9 years, SD = 16.5). Of the 12.5% of patients diagnosed with mood disorders, 5.0% (n = 29) were major depressive disorder, and 6.7% (n = 40) were minor depressive disorder. The odds ratio for co-occurrence of major depressive disorder with generalized anxiety disorders and major depressive disorder with anxiety disorders (NOS) was 11.5 (95% CI: 2.17–18.45) and 8.00 (95% CI: 3.19–20.07), respectively. The PHQ (Patient Health Questionnaire) study in Japan was conducted in eleven primary care sites. A total of 1409 adult patients (611 males, 797 females; mean age: 56.2 years, SD: ±20.4) completed the PHQ in full. The prevalence of diagnosis of any mood disorder or any anxiety disorder was 25.0%. Of the 15.8% of patients diagnosed with mood disorders, 5.3% were for major depression and 8.4% for other depressive disorders. The odds ratio for co-occurrence of major depressive disorder with other anxiety disorders was 30.4 (95% CI: 13.19–70.28).