The prevalence rates of depression and generalised anxiety disorders (GAD) have consistently been found to be higher in women than men. The question is whether this is a true difference or an artefact of definition.

In the Zurich study, a young adult sample representative of a geographic area was investigated by six interviews from age 20/21 to 40/41. Major depressive episodes (MDE) were diagnosed by DSM-III-R and GAD by DSM-III criteria. 27 symptoms of depression and 21 symptoms of anxiety were assessed; in addition eight self-assessments were carried out with the Symptom-Checklist 90-R including the depression sub-scale (13 items) and the anxiety scale (10 items).

192 subjects suffered from MDE (72 males, 120 females) and 105 from GAD (43 males, 62 females). Up to the age of 40/41 the cumulative incidence rates for MDE were 22.8% (16.9% males, 28.6% females) and for GAD 14% (12.2% males, 15.6% females).

In both diagnostic groups women suffered more often than men from work impairment, social impairment and distress; they also reported more symptoms than men in the interviews and self-assessments. The greatest gender differences were found in the following symptoms of depression: worse in the morning, fearful, fear of bad luck, lack of sexual desire, low self-esteem, guilt, hopelessness, crying easily, muscle tension, tiredness, increased appetite, weight gain and loss, and symptoms of anxiety: easily startled, dizziness and frequent urination,.

Compared to men, women suffer more often and more severely from both major depression and generalised anxiety disorder.