Screening for somatization and depression in Saudi Arabia: a validation study of the PHQ in primary care

Somatization, the tendency to seek treatment for medically unexplained physical symptoms, is an important issue in primary care practice. This study examines the somatoform, depression, and anxiety modules of the Patient Health Questionnaire (PHQ), a screening instrument for the identification of somatoform and other mental disorders. We also utilized the PHQ to measure the prevalence of somatization and co-morbid depression in Saudi Arabian primary care patients.

This is a cross sectional study of 431 male and female Saudi Arabian primary care patients with a two stage design for purposes of validation of the somatoform, depression and anxiety modules of the PHQ. The self administered Patient Health Questionnaire was given to 431 primary care patients and, of this group, the first, consecutive 173 patients (40 percent) were interviewed by mental health professionals using the Structured Clinical Interview (SCID-R) as the criterion standard for validation of the PHQ in the Saudi population. The PHQ was then used to measure the prevalence of somatization and depression in the remaining 258 patients.

The somatoform and depression modules of the PHQ were found to be valid in a Saudi population using the criterion standard of SCID based psychiatric interviews. Agreement between the PHQ and psychiatric interviews was (kappa = .65) for both somatoform disorders and depression but the anxiety module was weak in terms of sensitivity (.37) and agreement with the criterion standard (k = .37). Clinically significant rates of somatization (19.3 percent) and depression (20 percent) were identified in this population.

The prevalence of somatization and co-morbid depression in a primary care population in Saudi Arabia is similar to published rates in the U.S. and worldwide. It is possible to screen primary care patients for mental disorders in international settings and the PHQ is valid instrument for that purpose.