Disturbed sleep and circadian dysfunction, represented by rest-activity pattern abnormalities, may be a key predictor of symptom severity in patients with borderline personality disorder (BPD), according to study results published in Acta Psychiatrica Scandinavica.

Niall McGowan, PhD, from the department of psychiatry, University of Oxford, Warneford Hospital, United Kingdom, and colleagues abstracted data from a longitudinal cohort study conducted between March 2014 and February. Patients with bipolar disorder and BPD were recruited from outpatient services in Oxfordshire, England, and healthy volunteers were recruited from the community. For 28 consecutive days, participants wore GENEActiv Original actigraphs, which contained triaxial accelerometers to record movement and rest-activity patterns, including interdaily stability, intradaily variability, and relative amplitude (RA). Participants completed the Barratt Impulsiveness Scale at baseline and filled out a smartphone-based daily mood variability questionnaire for at least 3 months, with the option to continue for 12 months or longer.

Exploratory classification analyses were performed to assess the ability of actigraphy to distinguish between BPD, bipolar disorder, and healthy status. The area under the receiver operating characteristic curve (AUC) was used to assess the classification accuracy of each variable, including interdaily stability, intradaily variability, RA, and onset of the least active consecutive 5- and 10-hour periods (L5 and M10 onset, respectively).

The study involved 87 participants with valid actigraphy recordings: 31 with bipolar disorder (67.7% women; mean age, 39.2±12.2 years), 21 with BPD (90.5% women; mean age, 34.1±10.5 years), and 35 healthy controls (68.6% women; mean age, 39.5±12.5 years). Overall, among patients with BPD, greater symptom severity was associated with less stability and lower RA. Impulsivity and mood instability were each negatively correlated with interdaily stability (r, −0.663 [P =.012] and r, −0.773 [P =.001]) and RA (r, −0.616 [P =.020] and r, −0.694 [P =.006]), respectively. The same trends were not observed for healthy controls or patients with bipolar disorder.

Mood instability in BPD also predicted elevated intradaily variability in rest-activity patterns (r, 0.662; P =.006), later onset of daily activity (M10 onset; r, 0.553; P =.028), and more nocturnal arousal (L5 activity; r, 0.560; P =.028). Among actigraphic summary variables, L5 onset could reliably distinguish between BPD and healthy controls (AUC, 0.83) and between BPD and bipolar disorder (AUC, 0.79). Other actigraphic variables had relatively poor classification accuracy.

These data highlight the significance of rest-activity patterns in the symptoms of BPD. As study limitations, the investigators noted that the small cohort size prevented stratification by medication and comorbidities.

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“The associations described here indicate several translational opportunities for BPD treatment,” the investigators concluded. “Stabilisation and consolidation of rest-activity rhythms might be considered a primary target for adjunctive treatment if indeed symptoms are in part driven by sleep and circadian rhythm disturbances.”

Disclosure: One study author declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures

Reference

McGowan NM, Goodwin GM, Bilderbeck AC, Saunders KEA. Actigraphic patterns, impulsivity and mood instability in bipolar disorder, borderline personality disorder, and healthy controls [published online January 8, 2020]. Acta Psychiatr Scand. doi:10.1111/acps.13148