New research highlights the shared and unique characteristics of sleep and rest-activity rhythm measures among patients with schizophrenia.
Patients with schizophrenia spectrum disorder experience longer total sleep time and rest periods and lowered levels of activity than healthy controls, according to new research.1
The new data from a multinational team of investigators also noted greater abnormalities in sleep rhythms among residential patients with schizophrenia than outpatients or healthy controls, which could contribute to more severe symptoms associated with their mental illness. The findings suggest a need to investigate the impact of improved sleep on said schizophrenia symptoms and overall patient quality of life.
Led by Ahmad Mayeli, PhD, a postdoctoral associate at the University of Pittsburgh and Alice D. LaGoy, PhD, a postdoctoral researcher at the Naval Health Research Center, investigators examined patterns in sleep and rest-activity rhythm (RAR) among residential and outpatient patients with schizophrenia, compared to healthy controls and one another. The additionally sought to learn whether symptoms of schizophrenia and their severity differed between patient groups based on sleep and RAR.
“Altered sleep and RAR parameters have been found to be related to the clinical symptoms of (schizophrenia),” investigators wrote. “Among those, negative symptoms, which contribute significantly to reduced social and psychosocial functioning, less working capacity, decreased goal-oriented activities, and ultimately a lower quality of life in schizophrenia have been associated with longer total sleep time and lower motor activity patterns in these patients.”
The team recruited patients aged 18 – 56 years old with a DSM-5 defined schizophrenia spectrum disorder diagnosis, currently receiving treatment at 1 of 10 residential or outpatient facilities in Italy’s Department of Mental Health (DMH), and with good knowledge of the Italian language.
Psychiatrist or psychologists collected individual information on current patient diagnosis, illness duration and lifetime duration of psychiatric hospitalizations. Psychopathology severity was assessed via the 24 item Brief Psychiatric Rating Scale (BPRS), while psychosocial functioning was measured by the 43-item Specific Levels of Functioning Scale (SLOF).
Negative symptom severity was assessed via the 13-item Brief Negative Symptom Scale (BNSS), while RARs and sleep health were gauged by metrics determined by a 7-day assessment via actigraphy watch.
The final assessment included 230 patients, including 122 with schizophrenia and 108 health controls. Among patients with schizophrenia, 68 (55.7%) were residential and 54 (44.3%) were outpatient.
Total sleep time (TST) per actigraphy were greater in both schizophrenia groups compared to healthy control (P <.001); both patient groups additionally showed greater lengths of rest per RAR and most active 10 hours (M10).
Residential patients with schizophrenia reported higher intra-daily variability (IV), indicating daily rhythm fragmentation, than healthy controls.
Among the 2 schizophrenia patient groups, residential patients reported lower M10 than outpatients, whereas the opposite was true for IV (P <.001).
Regarding negative symptom severity, residential patients reported higher scores than outpatients. Inter-daily stability (IS) was significantly associated with residential schizophrenia patient status for negative symptom severity, but not with outpatient status.
There were no significant correlations between sleep and RAR variables, BPRS total score and positive symptoms.
In a press release accompanying the data, study senior author Fabio Ferrarelli, MD, PhD, associate professor of psychiatry at University of Pittsburgh, noted the findings highlighted how residential patients with schizophrenia have more stable daily routines than outpatients.2
“We tend to think of stable routines as a good thing, but when these routines become too rigid, they can present a problem,” he said. “In our study, this rigidity in daily rhythms was strongly correlated to the severity of negative mental health symptoms in residential patients with schizophrenia.”
In general, the findings support strategies to improve mental health including variation of daily routines and more daily movement.
“Especially as people get older, we tend to get deep into our routines,” Ferrarelli said. “Routines provide a sense of control to our lives and can be very beneficial. But if a routine is too rigid, it can backfire.”
The investigators concluded their study demonstrated the shared and unique characteristics of sleep and RAR measures among patients with schizophrenia in the residential and outpatient care setting.
“Building on these findings, future work will help establish whether improving some of these measures may ameliorate the quality of life and clinical symptoms of schizophrenia spectrum disorder patients,” they wrote.