Background. Primary care attenders with a common mental disorder (CMD) frequently present with somatic symptoms. This study aimed to examine somatic and psychological models of CMD in primary care attenders in India.

Methods. Cross-sectional survey of attenders at two primary care clinics. Psychiatric caseness was determined on three criteria: standardized psychiatric interview (biomedical criterion), patients' self-assessment of emotional disorder (emic criterion) and health care provider diagnosis. The GHQ-12 and the PPQ, which emphasize psychological and somatic symptoms respectively, were used as screening instruments.

Results. Although somatic symptoms were the presenting complaints for 97% of subjects, 51% of subjects with a biomedically defined CMD had a psychological illness attribution. Patients with psychological attributions were more likely to be women, to have a longer duration of illness, to have higher CISR scores and were more likely to be recognized by the primary health care (PHC) physician. The GHQ-12 was superior to the PPQ in identifying cases of CMD against the biomedical criterion for both psychologizers and somatizers; both instruments performed equally well against the emic and care provider criteria.

Conclusions. Psychological models may be acquired by patients as CMD becomes more chronic or severe, making them more likely to be detected by PHC physicians. Psychological symptoms are superior to somatic symptoms in detecting CMD. Shorter versions of the GHQ have comparable discriminating abilities to the 12-item version and offer the practical advantage of brevity, which may make them more acceptable to PHC physicians as a clinical screening tool.