The investigation of motor activity levels in a community based depressed psychiatric outpatient sample

The relationship between affective illness and activity level as described in the diagnostic criteria of the Diagnostic and Statistical Manual-Third Edition (DSM-III) and DSM-III-R (a revision of DSM-III) was examined in this study. Research participants consisted of 11 women who were receiving treatment at a community mental health center for a Major Depressive Disorder (MDD) and 10 contrast subjects who were continuing education students at a public college in the same community. All subjects were between the ages of 20 and 40. The Beck Depression Inventory was administered to all subjects; its main use was to screen contrast subjects for depression. Each person wore an Actometer on the dominant wrist for 14 consecutive days and nights. Readings were taken twice daily: the first thing in the morning upon awakening and at night when retiring to bed. It was hypothesized that differences between the two groups of subjects would be found such that the depressed group would exhibit less activity during the daytime, more activity during the nighttime, and less overall (24 hour) activity than the contrast group. The length of the nighttime, sleep, interval and the two-week data collection period were also examined. An Analysis of Variance indicated that significant differences existed in daytime activity and 24 hour activity with the depressed subjects exhibiting less activity than the contrast group during those intervals. No significant difference in activity was found during the nighttime interval. However, the depressed group spent a significantly greater period of time in the nighttime interval than did the contrast group. No differences were found either within or between groups when Week 1 of data collection was compared with Week 2. The results indicate that DSM-III diagnostic criteria of psychomotor retardation or agitation for MDD were applicable to the depressed group of subjects for the daytime, but not for the nighttime. The use of psychotropic medications in the depressed group was noted as a potential confound and a limitation of the study. The preferred methodology would entail use of a nonmedicated depressed group. A second limitation was noted in the need for subjects to actively participate in the data collection process. A computerized activity monitor would have facilitated this process