Nonorganic insomnia in panic Disorder: comparative sleep laboratory studies with normal controls and placebo-controlled trials with alprazolam

Abstract

Objective and subjective sleep and awakening quality was investigated in 11 drug-free patients (4 females, 7 males) aged 30-55 (mean: 44+/-9) years with nonorganic insomnia (F 51.0) related to panic disorder (F 41.0) as compared with 11 age- and sex-matched normal controls aged 30-58 (mean: 44+/-9) years, utilising polysomnography (PSG) and psychometry. PSG demonstrated decreased sleep efficiency (primary target variable), total sleep time (TST) and S2 as well as increased middle and late insomnia, S1, S3+S4, snoring and PLM in patients. There were no intergroup differences in REM variables. Subjective sleep quality deteriorated, as did drive and fine motor activity in the morning, while concentration increased. Blood pressure in the evening and morning and pulse rate in the evening were elevated. These differences as compared with normals were distinct from those observed in other sleep disorders. In a subsequent acute, placebo-controlled cross-over design study, patients received alprazolam 0.5 mg (Xanor((R));) and placebo. As compared with placebo, alprazolam induced an increase in sleep efficiency (primary target variable), TST and S2, a decrease in wakefulness during the total sleep period, S3+S4 and the oxygen desaturation and PLM indices, and improved subjective sleep quality, somatic complaints, drive, affectivity and drowsiness in the morning. There were no changes in REM variables. Thus, alprazolam induced changes that were opposite to the differences observed between patients and controls before treatment, thereby normalizing sleep and awakening quality. As observed in insomnia related to GAD and subsequent benzodiazepine therapy, the present study also points to a key-lock principle in the treatment of insomnia caused by anxiety disorders and neurophysiologically visualizes processes at the receptor level (e.g. benzodiazepine agonists versus inverse agonists). Copyright 2000 John Wiley & Sons, Ltd.