Sleep quality in persons with mental disorders: Changes during inpatient treatment across 10 diagnostic groups

Sleep disturbances have been documented across a range of mental disorders, particularly depression. However, studies that have examined sleep quality in large samples of different diagnostic groups and that report how sleep quality changes during inpatient treatment have been scarce. This retrospective, observational study examined changes in sleep quality during inpatient treatment at a psychosomatic hospital in Germany from admission to discharge as a function of 10 diagnostic groups. Data of 11,226 inpatients were analysed who completed the Pittsburgh Sleep Quality Index as part of the routine diagnostic assessment at admission and discharge. All diagnostic groups showed impaired sleep quality (Pittsburgh Sleep Quality Index score > 5). Patients with trauma‐related disorders had the lowest sleep quality and patients with obsessive–compulsive disorder had the highest sleep quality. While sleep quality significantly improved in each diagnostic group, changes differed in size, with patients with trauma‐related disorders showing the smallest improvement and patients with eating disorders showing the largest improvement. The current study documents impaired sleep quality in inpatients with mental disorders and shows that sleep problems are a transdiagnostic feature in this population. Results also resonate with earlier suggestions that sleep disturbances represent a key feature of trauma‐related disorders in particular and the need for trauma‐specific sleep interventions. Although sleep quality significantly improved during disorder‐specific inpatient treatment in all diagnostic groups, average scores were still clinically elevated at discharge. Thus, a future avenue would be to examine whether adding sleep‐specific treatment elements fosters both short‐ and long‐term success in the treatment of mental disorders.


Summary
Sleep disturbances have been documented across a range of mental disorders, particularly depression. However, studies that have examined sleep quality in large samples of different diagnostic groups and that report how sleep quality changes during inpatient treatment have been scarce. This retrospective, observational study examined changes in sleep quality during inpatient treatment at a psychosomatic hospital in Germany from admission to discharge as a function of 10 diagnostic groups. Data of 11,226 inpatients were analysed who completed the Pittsburgh Sleep Quality Index as part of the routine diagnostic assessment at admission and discharge. All diagnostic groups showed impaired sleep quality (Pittsburgh Sleep Quality Index score > 5). Patients with trauma-related disorders had the lowest sleep quality and patients with obsessive-compulsive disorder had the highest sleep quality. While sleep quality significantly improved in each diagnostic group, changes differed in size, with patients with trauma-related disorders showing the smallest improvement and patients with eating disorders showing the largest improvement. The current study documents impaired sleep quality in inpatients with mental disorders and shows that sleep problems are a transdiagnostic feature in this population. Results also resonate with earlier suggestions that sleep disturbances represent a key feature of trauma-related disorders in particular and the need for trauma-specific sleep interventions. Although sleep quality significantly improved during disorder-specific inpatient treatment in all diagnostic groups, average scores were still clinically elevated at discharge. Thus, a future avenue would be to examine whether adding sleep-specific treatment elements fosters both short-and long-term success in the treatment of mental disorders.  (Baglioni et al., 2016;Lijun et al., 2012).
However, studies that have examined sleep quality in large samples of different diagnostic groups and that report how sleep quality changes during psychotherapeutic treatment have been scarce (Schennach, Feige, Riemann, Heuser, & Voderholzer, 2019). Therefore, this report examines = 8.6 (SD  changes in sleep quality during inpatient treatment from admission to discharge as a function of 10 diagnostic groups in more than 11,000 patients with mental disorders. which are converted to seven component scores, internal reliability of which was ω = 0.758 at admission and ω = 0.783 at discharge. Higher total scores represent lower sleep quality. Changes in PSQI total scores from admission to discharge as a function of diagnostic groups (based on ICD-10 categories; Table 1) were examined with analyses of variance and paired t-tests. The data that support the findings of this study are openly available at https://osf.io/82wmp.
F I G U R E 1 Mean sum scores of the Pittsburgh Sleep Quality Index at admission and discharge as a function of diagnostic groups. Error bars indicate the standard error of the mean. Note that higher scores represent lower sleep quality In line with previous findings, the current study documents impaired sleep quality in inpatients with mental disorders (Baglioni et al., 2016;Lijun et al., 2012;Schennach et al., 2019). Specifically, average PSQI scores were above the cut-off score of 5-indicating poor sleep quality (Buysse et al., 1989)-in all diagnostic groups, suggesting that sleep problems are a transdiagnostic feature in this population. Of note, however, is that results are limited to inpatients that are typically treated in psychosomatic hospitals in Germany and, thus, are not representative for the entire population of inpatients with mental disorders (including, e.g., psychiatric inpatients with substance use or psychotic disorders).
In contrast to previous reports, which found the lowest selfreported sleep quality and the most severe alterations in polysomnographic variables in patients with depression (Baglioni et al., 2016;Lijun et al., 2012), patients with trauma-related disorders showed the lowest sleep quality in our sample. However, this result is in line with previous findings from our hospital (Schennach et al., 2019), and with earlier suggestions that sleep disturbances represent a key feature of post-traumatic stress disorder (Germain, 2013). Furthermore, patients with trauma-related disorders showed the smallest improvements in sleep quality from admission to discharge. Thus, the current findings resonate with recent suggestions that highlight the need for traumaspecific sleep interventions in the treatment of trauma-related disorders (Miller, Brownlow, & Gehrman, 2020).
Finally, although disorder-specific inpatient treatment significantly improved sleep quality in all diagnostic groups in the current study, average scores were still clinically elevated at discharge. Thus, a future avenue would be to examine whether low sleep quality at discharge is predictive of poorer long-term treatment outcome, and whether adding sleepspecific treatment elements fosters both short-and long-term success in the treatment of mental disorders. Such transdiagnostic, sleep-specific treatment programs for inpatients with mental disorders are currently under development (Sheaves et al., 2018), and preliminary feasibility trials suggest that they have the potential to improve sleep quality and possibly other health outcomes as well (Schneider et al., 2020).