Clinical and EEG Sleep Changes in Primary Dysthymia and Generalized Anxiety: A Comparison with Normal Controls

Abstract

All night EEG sleep recordings and clinical assessments of sleep quality were performed in normal controls, patients with generalized anxiety disorder and primary dysthymia. Patients were selected according to DSM-III R. Changes of sleep architecture, namely a reduction of slow wave sleep, are similar in generalized anxiety and dysthymia. Also the two groups do not exhibit the REM sleep disturbances usually observed in affective illness. Duration and continuity measures are unchanged in dysthymics, but anxious patients show some features of insomnia. The analysis of subjective aspects of sleep showed no relevant differences between the two groups of patients. Using a conventional set of EEG sleep parameters, primary dysthymia seems closer to anxiety disorders than to affective illness. However, the reduction of slow wave sleep in dysthymics and anxious patients may have different pathogenic meanings and the analysis of nonconventional sleep parameters may prove useful in this regard.

Sleep and Anxiety Disorders

“…High comorbidity with major depression has generated interest in comparing biological markers of the disorders. Latency to REM sleep was normal in these studies, in contrast to findings from major depression where REM sleep latency is reduced (11,12,13).…”

“…Studies utilizing objective sleep recordings corroborate the reported associations of GAD and insomnia by demonstrating impaired sleep initiation and maintenance in persons with GAD (11,12,13). High comorbidity with major depression has generated interest in comparing biological markers of the disorders.…”

Sleep Anomalies in the Chronic Fatigue Syndrome

“…Physical deconditioning was demonstrated in some studies in CFS [38]. Elective stage 4 impairment without stage 3 involve ment is not specific for CFS since this was also reported in MD, GAD and dysthymia [39][40][41], Alpha intrusion in NREM sleep rather than SWS duration per se could per haps have physiopathological relevance in FM and CFS. Studies about alpha sleep in CFS showed conflicting results [6.…”

EEG in psychiatric practice: to do or not to do?

“…Interestingly, a small study (Arriaga 1991) reported that EEG sleep recordings of participants with primary dysthymia showed reduced slowwave sleep and absence of REM sleep disturbances. These indicate that biologically, primary dysthymia may be closer to generalised anxiety disorder than to affective disorder.…”