Symptom reports in severe chronic insomnia

STUDY OBJECTIVES: To describe patterns and severities of the daytime and nighttime symptoms of chronic insomnia patients. DESIGN: Exploratory chart review from clinicians' evaluation summaries, a self-report screening instrument, the Pittsburgh Sleep Quality Index, the Beck Depression Inventory, the Epworth Sleepiness Scale, and the Hopkins Symptom Checklist-90 (HSCL90). SETTING: A regional sleep disorders referral clinic. PATIENTS OR PARTICIPANTS: 94 patients with chronic insomnia (DSM-IV code 307.42), classified into the subgroups "Primary Insomnia," "Depression-Related," "Anxiety-Related," and "Other". INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Frequent symptoms occurred not only in nocturnal domains (e.g., sleep disturbances, environmental sensitivity), but also in daytime domains (e.g., cognitive difficulties, sleepiness). Compared to primary insomnia patients, those with depression-related insomnia endorsed more severe symptoms. All subgroups endorsed a generally similar symptom profile when single symptoms were considered in isolation. When considered conjointly, severe symptoms typical of depression and generalized social alienation had a high negative predictive value for primary insomnia. The number of severe symptoms on the HSCL90 was related to fewer sleep hours in the nonprimary insomnia subgroup but not in the primary insomnia subgroup. CONCLUSIONS: Patients with chronic insomnia report significant daytime as well as nighttime symptoms. Depression-related and primary insomnias were separable only by some highly characteristic symptoms of depression. Diagnostic subgroups of insomnia patients may vary in how their overall distress relates to diminished self-reported sleep. Nighttime and daytime symptoms need to be assessed together when measuring insomnia severity.