Development and validation of a questionnaire for anxiety and depression in Pakistan.
BACKGROUND: Currently clinicians and researchers in Pakistan have to use translated western instruments to screen for anxiety and depressive disorders. This study investigated the local idioms of emotional distress in Pakistan to develop a culturally valid and easy-to-use instrument to screen for common mental disorders in general clinical settings. METHODS: A systematic survey was conducted of psychiatric case notes of patients attending clinics in Peshawar and Lahore, diagnosed with anxiety or depressive disorders, to identify the range of common idioms of psychological distress. A pilot version of the questionnaire was refined and validated among a composite sample of 330 patients in inpatient, outpatient and rural community settings. ICD-10 Diagnostic Criteria for Research were used to define cases and patients' relatives acted as normal controls. RESULTS: The pilot version of the questionnaire was reduced to 42 items based on odds ratios between cases and controls. Anxiety symptoms were generally reported by depressed patients, but not vice versa. Finally 30 items were selected, in two sub-scales. This final version achieved sensitivity, specificity, and positive and negative predicted values of over 90% when comparing cases and controls. LIMITATIONS: This questionnaire was based on what patients tell doctors and may not capture the entire repertoire of local idioms of distress. The validation study was conducted only in an Urdu/Punjabi speaking population, in Lahore and surrounding areas. CONCLUSIONS: The Pakistan Anxiety and Depression Questionnaire consists of an anxiety/depression scale and a depression scale, each of 15 items. It demonstrates excellent validity as screening instrument for anxiety and depressive disorders in clinical settings in Pakistan.