Actigraphic assessment of motor activity in acutely admitted inpatients with bipolar disorder

摘要

Introduction: Mania is associated with increased activity, whereas psychomotor retardation is often found in bipolardepression. Actigraphy is a promising tool for monitoring phase shifts and changes following treatment in bipolar disorder.The aim of this study was to compare recordings of motor activity in mania, bipolar depression and healthy controls, usinglinear and nonlinear analytical methods.Materials and Methods: Recordings from 18 acutely hospitalized inpatients with mania were compared to 12 recordingsfrom bipolar depression inpatients and 28 healthy controls. 24-hour actigraphy recordings and 64-minute periods ofcontinuous motor activity in the morning and evening were analyzed. Mean activity and several measures of variability andcomplexity were calculated.Results: Patients with depression had a lower mean activity level compared to controls, but higher variability shown byincreased standard deviation (SD) and root mean square successive difference (RMSSD) over 24 hours and in the activemorning period. The patients with mania had lower first lag autocorrelation compared to controls, and Fourier analysisshowed higher variance in the high frequency part of the spectrum corresponding to the period from 2–8 minutes. Bothpatient groups had a higher RMSSD/SD ratio compared to controls. In patients with mania we found an increasedcomplexity of time series in the active morning period, compared to patients with depression. The findings in the patientswith mania are similar to previous findings in patients with schizophrenia and healthy individuals treated with aglutamatergic antagonist.Conclusion: We have found distinctly different activity patterns in hospitalized patients with bipolar disorder in episodes ofmania and depression, assessed by actigraphy and analyzed with linear and nonlinear mathematical methods, as well asclear differences between the patients and healthy comparison subjects.