Anxiety and depression in paradoxical insomnia: a case–control study

PURPOSE: To compare anxiety and depression among patients with paradoxical insomnia (Para-I), patients with psychophysiological insomnia (Psy-I), and normal sleepers (NS). PATIENTS AND METHODS: A cross-sectional case–control study was conducted in patients with Para-I (n=63), patients with Psy-I (n=63), and NS (n=63) from southwest China. The three groups were matched for age (mean age: 42.0±10.30 years), gender (per group: male =22; female =41), educational level, and nature of occupation. Anxiety and depression were evaluated using the Self-Rating Anxiety Scale and Self-Rating Depression Scale and compared among the groups. RESULTS: Concerning anxiety, patients with Para-I had a significantly higher mean Self-Rating Anxiety Scale score (P<0.05) and significantly higher incidence of anxiety compared to NS (P<0.0167). There were no significant differences between the two insomnia groups on anxiety measures. Concerning depression, patients with Para-I had a significantly higher mean Self-Rating Depression Scale score than patients with Psy-I and NS (both, P<0.05), as well as a significantly higher incidence of moderate to severe depression than in the Psy-I group and NS (both, P<0.0167). CONCLUSION: Both Psy-I and Para-I patients had significantly higher anxiety and depression than NS. Compared to Psy-I, Para-I patients had slightly (but not significantly) lower anxiety and significantly higher depression.