Personality, anxiety and mood traits in patients with sleep-related breathing disorders: effect of reduced daytime alertness.

OBJECTIVE The etiology of depression and personality disorders in patients with sleep-disordered breathing (SDB) is not well defined and it is still unclear if they are directly related to the severity of the disease. In this study we test the hypothesis as to whether daytime sleepiness largely contributes to appearance of mood disorders. METHODS Sixty patients diagnosed as having snoring (n=16) or OSA (n=44) were examined. Daytime sleepiness was assessed by the administration of the Epworth Sleepiness Scale (ESS) and by the Maintenance Wakefulness Test (MWT). The Hospital Anxiety (HAD-A) and Depression (HAD-D) Scale and the Temperament and Character Inventory (TCI) questionnaires were used for psychopathological evaluation. RESULTS The mean HAD-A score was 6.9+/-0.45 and the average HAD-D score was 4.6+/-0.48, with no significant difference between snorers and OSA patients. Anxiety was present in 16% of cases and depression in 7%. The HAD-D score was related to the ESS score (R=0.37, P=0.003), the mean sleep latency at the MWT (R=-0.34, P=0.04), and the mean low SaO(2), ESS score alone explaining the 17% of variance in the HAD-D score. Compared to controls, there were no differences in almost all TCI scores, with novelty-seeking temperament score higher in patients. No relationships were found between HAD or TCI scores and apnea density. CONCLUSIONS We conclude that among patients evaluated for SDB, higher depression scores show an association with reduced daytime alertness, which therefore may have important effects on mood.