Time estimation and chronopathology in endogenous depression.

In recent empirical research on endogenous depression, time estimation has frequently been discussed in the context of chronopathological reflections, without empirical evidence of the postulated correlations between changes in speed of the "internal clock" and indicators of time estimation. In three single case studies, we looked for potential correlations between rhythmic processes (especially diurnal mood variations) and time estimations by primary depressive patients. Though our studies suggest a correlation between retardation and time estimation in patients with clear changes (trends) in the depressive mood, our results do not support any chronopathological speculations. According to our results, correlations between time estimation and retardation or depressive mood are dependent on distinct trends and not on rhythmic patterns.