[Prevalence, expression and impact of depressive disorders in primary care]

To determine the prevalence and forms of clinical expression of depressive disorders in primary care patients. To analyse the under-detection of depression by primary care doctors.

Descriptive and transversal study, with two-stage sampling. Setting. Primary care consultations in the Camp de Tarragona area.

1000 consecutive patients visiting their doctor for any reason will make up the first-stage sample. Of these 350 go on to the second stage (all the positive results in the screening for depression test plus a random one-seventh of the negative results).

The first stage will consist of the screening of the sample for depressive disorders with Zung's Self-Rating Depression Scale. In the sub-sample that will go on to the second stage, the Structured Clinical Interview for DSM-IV Disorders will be used to establish diagnoses of depressive disorders and other co-morbid psychiatric disorders. There will also be a range of specific questionnaires to find reasons for consultation and the form of presentation of an eventual depressive disorder, medical co-morbidity, medication taken, use of health services, the functional and vital repercussions of depression. A questionnaire for the patient's G.P. will assess and detect depression.

The study will enable us to check the validity for our patients of pre-suppositions on depression in primary care obtained from studies in other countries with different health structures and social and cultural conditioners, and to find diverse information extrapolated from specialist studies.