A pilot study of subjective daytime alertness and mood in primary insomnia participants using ecological momentary assessment.

This pilot study compared daytime symptom ratings in primary insomniacs (n = 7) and age-matched controls (n = 8). Participants completed sleep diaries and rated their daytime symptoms using a Daytime Symptom Diary (DSD) 4 times per day for 1 week. DSD responses were collapsed into 4 domains: mood, subjective alertness, energy, and concentration. The level and variability of DSD domains, and correlations between the domains and sleep diary characteristics, were examined. Significant Group x Time of Day interactions were observed in values for each DSD domain, with the most consistent group differences occurring in the morning. Coefficients of variation for DSD domains were greater in the insomnia group. Frequent measures of daytime symptoms may be useful outcomes in insomnia studies.