Psychomotor Activity in Unipolar and Bipolar Depressive Patients

Abstract

Findings on the psychomotor activity of unipolar versus bipolar depressive patients and on the relationship between psychomotor activity and sleep are divergent. In this study, the psychomotor activity of 37 depressive patients (25 unipolar, 12 bipolar) was examined by means of continuous actometric monitoring (48 h). The mean activity level of the unipolar depressives is higher (though not at a significant level) than that of the bipolar group. There is a weak but significant negative correlation between psychomotor activity and self-rated sleep time. Elderly and female patients display greater psychomotor activity than younger depressives and male patients. After matching for age and gender, the psychomotor activity of unipolar and bipolar patients is virtually identical; a significant correlation between psychomotor activity and sleep time cannot be established any more.

Motor Activity and Daily Variation of Symptom Intensity in Depressed Patients

“…Circadian rest-activity cycles [8,12] and ultradian activity patterns [9,11,13] can be monitored and ana lyzed by actigraphy. Differences in methodology (sensi tivity, epoch length, placement, kind of instrument) may alter data registration and results.…”

“…A sensitivity threshold for acceleration of 0.1 g omits possibly slower and less abrupt movements. However, complete registration of even slightest movements will probably not improve assess ment of overall spontaneous psychomotor and locomotor activity [9], The threshold of 0.1 g has been used in most studies [12] and may better provide a means for compar ing results among investigations. In order to measure vari ation over time, the sensitivity of the instrument used has to fit the extent of intraindividual time-dependent changes, which may depend on psychopathological symp toms.…”

“…Because no group compari sons were needed to test our hypothesis, the extent of intersubject reliability of actigraphic measurements was not relevant. An epoch length of 2 min has been used in similar studies [9], Epochs of 1-900 s have been described in the literature [12]. No data were found dealing with a possible effect of epoch lengths on results of actigraphic measures.…”

“…The instrument was worn by patients in a form similar to a wristwatch on the nondominant wrist. This method has been described before [9]. In brief, the instrument counts [he number of movements within a measuring intervall of 2 min.…”

“…However, relevance and prognostic value of these variations have been discussed controversely in the literature [6,7], Previous studies have investigated motor activity in depression. Bipolar depressive patients seem to be less active than unipolar subjects [2] and display less motor activity compared to healthy controls group [8] with marked hyperactivity in elderly unipolar female patients [9] and increased levels of locomotor activity in geriatric patients with unipolar depression [10], Actigraphic deter mination of immobility may distinguish endogenous from nonendogenous depression [11], Changes in motor activity seem to be related to regulation of circadian rhythms. Chronobiological patterns of motor activity were phase-advanced in bipolar depressed patients [8] and altered in patients with seasonal affective disorder and pediatric affective disorders [12], Basic activity levels correlated with clinical improvement of depression [ 13], depression rating scores were negatively correlated with total 24-hour activity counts [14], Morning versus eve ning motor activity has not yet been studied in unipolar depressed patients with melancholic features.…”