We studied 70 inpatients affected by Unipolar Depression, treated for three weeks with combined LT and venlafaxine. Two-third of the patients received LT following a predictive algorithm based on MEQ scores; the others received LT at 11:00 a.m. Severity of depression was rated on the Hamilton Depression Rating Scale (HDRS). A subgroup of patients wore activity monitors.
HDRS scores significantly decreased during treatment (Friedman's ANOVA: ¦Ö2 = 186.82, p < 0.00001). LT administered in the early morning showed a better relative efficacy than late morning (F = 4.576; p = 0.012) with the clinical improvement correlating with an advance in rest-activity rhythm acrophase (r = ?#xA0;0.336; p = 0.017). Season of hospitalization interacted with LT timing and time in influencing response to treatment (F = 3.101; p = 0.049) and season of episode recurrence significantly interacted with LT timing, season of hospitalization and time (F = 5.925; p = 0.0035).
The major limitation of the study is the small sample size when considering simultaneously LT schedules, season of treatment and recurrence. Moreover, even if none of the patients fulfilled DSM-IV criteria for seasonal pattern of recurrence, they were not administered any questionnaire about seasonality.
We confirmed the usefulness of LT as a non-pharmacological antidepressant therapy for non-seasonal depression. Season and timing of administration and timing of the rest-activity cycle affected response to treatment.