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

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 wi th nonorganic insomnia (F 51.0) related to panic disorder (F 41.0) as compa red with 11 age- and sex-matched normal controls aged 30-58 (mean: 44+/-9) years, utilising polysomnography (PSG) and psychometry. PSG demonstrated de creased sleep efficiency (primary target variable), total sleep time (TST) and S2 as well as increased middle and late insomnia, SI, 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 activit y in the morning, while concentration increased. Blood pressure in the even ing and morning and pulse rate in the evening were elevated. These differen ces as compared with normals were distinct from those observed in other sle ep disorders. In a subsequent acute, placebo-controlled cross-over design s tudy, patients received alprazolam 0.5 mg (Xanor*) 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 sl eep period, S3 + S4 and the oxygen desaturation and PLM indices, and improv ed subjective sleep quality, somatic complaints, drive, affectivity and dro wsiness in the morning. There were no changes in REM variables. Thus, alpra zolam induced changes that were opposite to the differences observed betwee n patients and controls before treatment, thereby normalizing sleep and awa kening quality. As observed in insomnia related to GAD and subsequent benzo diazepine therapy, the present study also points to a key-lock principle in the treatment of insomnia caused by anxiety disorders and neurophysiologic ally visualizes processes at the receptor level (e.g. benzodiazepine agonis ts versus inverse agonists). Copyright (C) 2000 John Wiley & Sons, Ltd.