What can alert the general practitioner to people whose common mental health problems are unrecognised?

To assess the characteristics of people with common mental health problems who are recognised by their general practitioner, and those who are not.

Two different case-finding techniques (brief self-report and structured diagnostic interview) were compared with GPs' independent assessments of patients' presentations as psychological and/or medical.

371 patients in general practices in metropolitan Sydney and rural New South Wales, with follow-up telephone interview as soon as possible after the GP visit. The study was conducted from 2001 to 2003.

Overall rates of disorder, measured by the 12-item Somatic and Psychological HEalth REport (SPHERE-12), and anxiety, depression and somatisation diagnostic categories of the Composite International Diagnostic Interview - Auto; rates of disability, assessed by the 12-item Short-Form (SF-12) General Health Survey's mental (MCS) and physical component scales; GP ratings of patients' psychological problems, and intended treatments.

The SPHERE-12 showed the highest rate of case detection and greater agreement with GP assessments of psychological reasons for presentation. Patients who presented with somatic symptoms alone were most likely to be overlooked by GPs: none of the 57 patients identified by SPHERE-12 with a somatic disorder were identified by GPs as psychological presentations. Specificity for the SPHERE-12 psychological scale changed from 72% to 93%, and from 84% to 96% for the combined psychological and somatic scale, when the criterion of an SF-12 MCS score < or = 40 was added.

Low rates of recognition of psychological problems by GPs, and infrequent treatment for those presenting with somatic symptoms, indicate a need for building GPs skills in the assessment and management of somatisation. The SPHERE-12 may be a useful screening tool for primary care if followed by further questioning and other methods to assess diagnosis and severity to target appropriate treatment.