Distribution of Active and Resting Periods in the Motor Activity of Patients with Depression and Schizophrenia

Abstract

ObjectiveAlterations of activity are prominent features of the major functional psychiatric disorders. Motor activity patterns are characterized by bursts of activity separated by periods with inactivity. The purpose of the present study has been to analyze such active and inactive periods in patients with depression and schizophrenia.MethodsActigraph registrations for 12 days from 24 patients with schizophrenia, 23 with depression and 29 healthy controls.ResultsPatients with schizophrenia and depression have distinctly different profiles with regard to the characterization and distribution of active and inactive periods. The mean duration of active periods is lowest in the depressed patients, and the duration of inactive periods is highest in the patients with schizophrenia. For active periods the cumulative probability distribution, using lengths from 1 to 35 min, follows a straight line on a log-log plot, suggestive of a power law function, and a similar relationship is found for inactive periods, using lengths from 1 to 20 min. For both active and inactive periods the scaling exponent is higher in the depressed compared to the schizophrenic patients.ConclusionThe present findings add to previously published results, with other mathematical methods, suggesting there are important differences in control systems regulating motor behavior in these two major groups of psychiatric disorders.

Motor activity patterns in acute schizophrenia and other psychotic disorders can be differentiated from bipolar mania and unipolar depression

“…Actigraphy studies that consider motor activity patterns in more complex time series analyses do, however, seem to be more promising regarding correlation with specific symptom characteristics. These studies have predominantly come from one group in Switzerland (Walther et al, 2009a;Walther et al, 2009b;Walther et al, 2014;Walther et al, 2015), and our collaborators in Bergen, Norway (Berle et al, 2010;Fasmer et al, 2016;Hauge et al, 2011). This research shows that negative symptoms correlate with reduced activity and inversely, that less rest is common during marked positive syndromes (Walther et al, 2009b).…”

Cytokines in Relation to Motor Activity in an Acute Psychiatric Population

“…Altered motor activity is gaining increased interest within psychiatric research and may be a prominent finding in an acute psychiatric setting (1,2). Traditionally, increased or abnormal activity is seen in ADHD, tic disorders, affective disorders, anxiety, and schizophrenia (3). Motor symptoms may also characterize different subtypes of unipolar depression and predict treatment response (2,4).…”

Patterns of motor activity in spontaneously hypertensive rats compared to Wistar Kyoto rats

“…We have used standard deviation (SD) and root mean square successive differences (RMSSD) to indicate the molar, overall level of variability. These measures have been used in the study of reaction time variability in ADHD patients [31] and also in the study of motor activity of psychiatric patients assessed with actigraphs [32–34]. For analyses of molecular behavioral variability, we included analyses of autocorrelations, which have been used to assess response variability in children with ADHD [2, 3].…”

“…For analyses of molecular behavioral variability, we included analyses of autocorrelations, which have been used to assess response variability in children with ADHD [2, 3]. Additionally, to investigate variability in different frequency domains, we have employed Fourier analyses, which is a well-established method in many different fields, and which have been used together with SD and RMSSD in studies of motor activity [32–34]. To obtain a measure of complexity we have used sample entropy and symbolic dynamics which are two methods that tolerate a reasonable degree of noise (as usually is the case with biological systems).…”

“…To obtain a measure of complexity we have used sample entropy and symbolic dynamics which are two methods that tolerate a reasonable degree of noise (as usually is the case with biological systems). Both methods were used in the actigraph-studies mentioned above [32–34] and also in the study of reaction time variability in ADHD patients where increased variability and reduced complexity were found [31]. …”