BackgroundFrance has high rates of psychotropic drug consumption and suicide in the elderly population, but it has not yet been possible to determine whether this is due to exceptionally high morbidity rates.AimsTo describe the first longitudinal population study of psychiatric disorder undertaken in France, and to estimate current and lifetime prevalences and age of onset of psychiatric disorder.MethodA study group of 1873 non-institutionalised persons aged 65 years and over was randomly recruited from the Montpellier district electoral rolls. The Mini International Neuropsychiatric Interview was used to assess current and lifetime symptoms. Cases identified by the application of DSM–IV criteria were reexamined by a clinical panel.ResultsForty-six percent of the study population had experienced a mental disorder in their lifetime, and 3.7% had made a suicide attempt. Lifetime prevalence of major depression was 26.5% and 30% for anxiety disorders. Current prevalence rates were 14.2% for anxiety disorders, 10.7% for phobia, 3% for major depression and 1.7% for psychosis.ConclusionsResults show very high rates of lifetime but not current major depression. Rates of current phobia and suicidal ideation in the very elderly are also high compared with other studies. The rates reported are likely to be underestimates.