Background: Whilst previous surveys of mental health literacy of general practitioners (GPs) have shown high rates of recognition of common mental disorders, few studies have been carried out into GPs' understanding of presentations in late life. This study aims to determine GPs' recognition of mental disorders in older people, their intentions regarding investigation, specialist referral and treatment, and their beliefs about prognosis.

Methods: Australian GPs who attended an educational seminar were administered questions based on clinical vignettes describing older people with depression, dementia and coronary heart disease.

Results: There was a high rate of recognition of all disorders amongst the 436 respondents. GPs demonstrated a high level of consistency about screening questionnaires, investigations and specialist referral in the dementia vignette. In contrast, less than half of GPs endorsed using a screening questionnaire or neuroimaging, and considered referral to a variety of medical specialties in the depression vignette. For both the depression and dementia vignettes, self-help treatments like walking, dietary advice or alcohol reduction were endorsed more frequently than an antidepressant or cholinesterase inhibitor respectively. Dementia tended to be viewed as having a poor prognosis, and late-life depression a moderate prognosis.

Conclusions: Actual or intended rates of diagnostic recognition, specialist referral and benzodiazepine prescription found in this study may not translate into clinical practice for a number of reasons. Non-specific treatments without a clear evidence base were considered as often as those with a stronger evidence base. There is a need to improve the knowledge of GPs with regard to screening and investigating late life depression and managing dementia.