The authors placed 84 patients who complained of insomnia into 10
diagnostic categories on the basis of medical, psychiatric, and
polysomnographic evaluations. Only half the patients had objectively
defined difficulty inducing or maintaining sleep when compared with 20
normal control subjects. However, all but 16 patients showed
polysomnographic evidence of some sleep disorder. Diagnostic categories
within the insomnia groups could be distinguished from one another by
polysomnography. Patients in only 3 of the 10 diagnostic categories showed
evidence of psychological distress on the MMPI; patients in the other 7
categories displayed few psychological symptoms. These results have
implications for the treatment of insomnia.Abstract Teaser