Abstract
Sleep and circadian problems are intertwined with serious mental illness (SMI). Thus, optimizing treatments that target comorbid sleep and circadian problems and SMI is critical. Among adults with sleep and circadian problems and SMI, the present study conducted a secondary data analysis of the Transdiagnostic Intervention for Sleep and Circadian Dysfunction (TranS-C). TranS-C targets a range of sleep and circadian problems and SMI with 15 modules, seven of which are optional. In a 'real world' sample recruited from a community setting (N=121, 52.07% female, 42.97% African American or Black), we aimed to (1) elucidate patterns of sleep and circadian problems that met criteria for full diagnoses and subdiagnostic symptoms across (a) the full sample and (b) SMI diagnoses, and (2) determine whether TranS-C optional modules were delivered as intended based on participants' sleep and circadian problems. Results indicated that most participants (> 85.0%) had full diagnoses or subdiagnostic symptoms of two or more sleep and circadian problems. Further, participants exhibited heterogenous comorbidities between sleep and circadian problems and SMI diagnoses. Specifically, participants with a schizophrenia spectrum disorder (n=50), bipolar disorder (n=35), and major depressive disorder (n=26) exhibited 25, 24, and 21 patterns of sleep and circadian comorbidity, respectively. Notably, most participants with insomnia, hypersomnia, and an advanced or delayed circadian rhythm phase disorder did not receive the intended TranS-C optional modules designed to target these problems. Results underscore sleep and circadian and SMI diagnostic complexity in the community. Additionally, findings reveal discrepancies between intended and 'real-world' use of treatment modules. Future research investigating clinician decision-making-particularly when treating patients with comorbidities or using modularized treatments-is needed.