Preliminary results of an epidemiological study in the general population of a small town near Paris are presented. This study investigates the prevalence of depressive and anxiety states and the risk factors associated with these disorders. The study methodology is reported in detail, especially the instruments chosen (some sections of the DIS/CIDI, questionnaires on social support, life events and self-rating questionnaires). Anxiety and depressive disorders are frequent in this population: life-time prevalence of Panic Disorder in men amounted to 2.3% and in women 3.1%, Generalised Anxiety Disorder in men 5.4% and in women 13.4%, Major Depressive Episode in men 8.5% and in women 21.9%. Panic Disorder is assessed with regard to different definitions and criteria (DSM III, DSM III-R). A wide difference in results is found according to the criteria used. Specifically, when anticipatory anxiety is taken into account, this increases the frequency rate of Panic Disorder. A significant comorbidity is found between anxiety and depressive disorders.