Circadian lighting effect for inpatients with schizophrenia: A prospective cohort study

In schizophrenia, nonspecific lighting likely causes sleep timing disturbances, leading to distress and poorer clinical status. However, the effect of exposure to circadian lighting on psychopathology outcome in schizophrenia remains unknown. Hence, this study aimed to develop such an intervention and investigate its impact on schizophrenia.

Twenty schizophrenia patients at a psychiatric nursing institute were monitored over 10 weeks, with assessments using the Brief Psychiatric Rating Scale (BPRS) and Mini-Mental State Examination (MMSE) conducted at baseline, weeks 3 (T1), 7 (T2), and 10 (T3).

Circadian lighting significantly improved BPRS scores between T1-T2 (p < .05) and T1-T3 (p < .001), with affectivity scores also showing significant enhancements postintervention. Notably, female participants exhibited substantial improvements in BPRS scores from T1 to T3 (p < .01), while male participants demonstrated significant gains in MMSE scores from T1 to T2 (p < .01).

Circadian lighting presents a promising intervention for improving psychiatric outcomes in schizophrenia, with distinct benefits observed across different psychopathological aspects and genders. These findings underscore the potential of lighting chronotherapy in psychiatric clinical practice and warrant further exploration in related research.