Subjective-Objective Sleep Discrepancy in Schizophrenia.

OBJECTIVE/BACKGROUND

Subjective methods are often employed for sleep assessment due to their ease of use, but the results may not concur with objective findings. This discrepancy may be present in schizophrenia; however, limited data are available. We performed a secondary analysis to evaluate the agreement between 1-week actigraphy and sleep diary-derived parameters and factors that contribute to subjective-objective sleep discrepancy.

PARTICIPANTS

66 outpatients with schizophrenia (mean age = 44.08 years; 45.45% males).

METHODS

Agreement between subjective-objective parameters was assessed using two-way repeated measures ANOVA, Pearson's correlation, and Bland-Altman plot. The magnitude of discrepancy was quantified using Cohen's

RESULTS

On average, sleep diaries overestimated sleep onset latency by 20.45 min, total sleep time by 37.63 min, and sleep efficiency by 4.29%, but underestimated wake after sleep onset by 33.28 min. Cohen's

CONCLUSIONS

Our findings show that differences between subjective and objective measurements of sleep are present in schizophrenia. Although actigraphy is not a standard procedure for sleep disturbance in schizophrenia, clinical judgment should be used if patients are suspected to have overestimated their sleep difficulties. Further studies should examine whether feedback based on actigraphy can benefit patients with schizophrenia and comorbid sleep disturbances.