Major depression is underdiagnosed by general practitioners, but the r
easons for this are not clear. This study aimed to establish the preva
lence of major depression and coexisting generalised anxiety disorder
in a rural general practice in the Orange Free State. It also assessed
the predictive value of a screening questionnaire for use by general
practitioners. The two practitioners evaluated 858 patients over a 4-w
eek period, Those who met the screening criteria, together with a rand
om sample of 60 patients who did not, were re-evaluated by a registrar
in psychiatry who was unaware of the findings of his colleagues. Of t
he patients studied, 134 (15,6%) had major depression; 59 of these (44
,0%) also had coexisting generalised anxiety disorder. The general pra
ctitioners had correctly diagnosed major depression in 32 patients (3,
7%) before the study started. The screening questionnaire had a 42% ch
ance of correctly identifying a patient with depression and a 97% chan
ce of correctly identifying a patient who did not have major depressio
n. Both practitioners were equally capable at identifying major depres
sion. The study confirmed both the high prevalence of depression in a
rural general practice and its low identification rate. It also showed
the advantage of using a screening questionnaire to alert practitione
rs to the possibility of depression in their patients.