Insomnia Related to Another Mental Disorder

Insomnia related to another mental disorder should be diagnosed when a patient has a predominant complaint of insomnia for at least 1 month that causes daytime symptoms and impaired functioning. The insomnia is judged to be related to a coexistent Axis I or II disorder, but the sleep complaint constitutes a distinct focus of treatment or patient concern. In many cases, patients will present primarily with a complaint of insomnia, and only on further questioning will they reveal symptoms of a mental disorder. This diagnosis should not be used if a patient has a concurrent medical or substance use disorder that might explain the symptoms.

The most common psychiatric disorders that present with prominent insomnia are mood disorders (including major depressive episode, dysthymic disorder, and manic episode), anxiety disorders (including generalized anxiety disorder and panic disorder), and psychotic disorders, predominantly schizophrenia. Patients with Axis II disorders such as borderline personality disorder and histrionic personality disorder often complain of chronic insomnia as well.

Behavioral/psychotherapeutic treatment Several behavioral interventions, either alone or in combination with pharmacotherapy, can benefit psychiatric patients with insomnia. For example, a clinical replication series with 100 outpatient insomniac patients showed that the degree of sleep pattern changes produced by a cognitive-behavioral intervention was similar in patients with psychophysiological, drug-dependent, or psychiatric insomnia (Morin et al. 1994b). Patients whose insomnia was associated with psychiatric disorders (mostly affective and anxiety disorders) had more severe sleep disturbances at baseline and did not achieve the same sleep patterns at posttreatment as either of the other two subgroups. However, there was little difference in the absolute levels of changes obtained on the various outcome measures, suggesting that even those patients with secondary insomnia benefited from the sleep-focused intervention.

In another clinical case series (Dashevsky and Kramer 1998) of 48 patients with comorbid psychiatric disorders (including 28 with depression), a short-term behavioral treatment for insomnia (six sessions over a 2-month period) produced moderate to clinically important improvements in 56% of the patients at the short-term follow-up. Improvements were noted for both sleep parameters and daytime functioning (e.g., fatigue, mood, social discomfort). Additional pilot studies have also examined the effect of behavioral interventions on the sleep of inpatient populations. In a naturalistic study (Edinger et al. 1989b) conducted on three psychiatric wards, elimination of daytime napping and strict enforcement of a regular arising time produced slight but consistent improvements in sleep initiation, continuity, and duration. In another study (Edelstein et al. 1984), reductions of caffeine intake among 10 psychiatric inpatients with sleep maintenance insomnia reduced the number of night wakings and the number of requests for hypnotic medications. Twenty psychiatric patients with secondary insomnia were treated on an inpatient basis with a combination of psychotherapy, behavioral therapy, and pharmacotherapy (Tan et al. 1987). After an average hospitalization of 38 days, 16 of the 20 patients were clinically improved on a subjective index of sleep quality. Finally, an innovative study by Holmes and colleagues (1995) evaluated a sleep management program specifically designed for patients with severe mental illness. First, they defined the content of the sleep management training module based on specific concerns of 23 patients with severe mental illness who also had sleep-related problems (education, sleep environment, sleep behaviors, and medications/drugs). Then, they pilot tested the training module with a second cohort of 18 participants (44% with a diagnosis of schizophrenia, 22% with major depression). The findings showed that patients increased both their knowledge of sleep management skills and their subjective ratings of sleep quality.