Sleep/wake regularity and cognition in college students using antidepressants

The current project examined sleep, sleep/wake regularity, and cognition in college students diagnosed with depression and using serotonergic antidepressants and in those without a depression diagnosis. Forty participants either using antidepressants (n = 20, 24.75 ± 6.82 years) or without a depression diagnosis (n = 20, 21.70 ± 2.74 years) wore actigraphs for two consecutive weeks (14 days). Cognitive tasks were completed on day 1 (along with demographic surveys) and day 14. Effect sizes indicated that compared to non-clinically depressed peers, participants using antidepressants exhibited slightly greater wake after sleep onset (d = 0.36) and lower sleep efficiency (d = 0.40); however, these differences were likely not noticed by the sleeper. No sleep regularity or cognitive differences were present between groups. Within the antidepressant group, higher dosage predicted greater time in bed (R² = 0.77), but less total sleep time (R² = 0.86). The time of day that participants took their antidepressant exhibited differential effects on certain cognitive parameters, such as procedural reaction time and spatial processing, and interactions with years of antidepressant use were found. Self-reported wake episodes also predicted better reaction time and inhibition in the antidepressant group. This study is the first to demonstrate that sleep/wake regularity is comparable between people using antidepressants and non-clinically depressed human samples. For individuals using antidepressants, years of use, dosage, and time of day of use have predictive qualities for reaction times, spatial processing, and inhibition.