Biopsychobehavioral correlates of insomnia, part 1: Role of sleep apnea and nocturnal myoclonus

In the first such comparative study, the prevalence of sleep apnea, sleep apneic activity, nocturnal myoclonus, and nocturnal myoclonic activity proved quite similar in 200 insomniac patients and 100 normal controls. None of the 300 subjects manifested the clinical condition of sleep apnea, while similar percentages (5% to 6%) of insomniacs and normal controls displayed nocturnal myoclonus. Thus, the claim that these conditions are common causes of insomnia is not substantiated by this controlled study. However, the presence of psychopathology clearly differentiated between the insomniacs and the controls. The authors conclude that the psychiatrist can thoroughly evaluate the insomniac patient by combining psychiatric assessment with a complete sleep history.