Studies have revealed that the prevalence of insomnia in patients with chronic schizophrenia is higher and related to cognitive impairment

Insomnia is an important public health problem that often occurs in people with schizophrenia and troubles the treatment and prognosis
of patients.
Studies have found a strong relationship between sleep and cognition in healthy people, and schizophrenia often presents with symptoms of insomnia and cognitive deficits
.
Therefore, the researchers speculate that the prevalence of insomnia in Chinese schizophrenia patients is higher and there is a correlation with cognition
.

Zhang Xiangyang's research group, Key Laboratory of Mental Health, Chinese Academy of Sciences, recruited 957 hospitalized schizophrenic patients (630 males and 327 females) for the study
.
Demographic, clinical, and insomnia data were collected using self-reported questionnaires, while psychopathological symptoms were assessed using a combined positive and negative scale (PANSS) and cognitive performance
assessed using a set of neuropsychological status rating scales (RBANS).

The results showed that 20.
2% of patients with chronic schizophrenia reported insomnia symptoms (193/957).

The total score of PANSS, positive symptoms, negative symptoms, and general symptoms in patients with schizophrenia and insomnia were significantly higher than those in non-insomnia patients, and the total score of RBANS, language, attention, and delayed memory were significantly lower than those in non-insomnia patients
.
Regression analysis showed that women, high overall PANSS scores, and insomnia drug use were independently associated
with insomnia.

Figure 1.
Cognitive comparison of patients with insomnia and non-insomnia schizophrenia

The findings suggest that patients with chronic schizophrenia have a higher prevalence of insomnia compared to healthy people, and patients with insomnia have worse
cognitive performance than those without insomnia.
The results of the study have clinical significance
for the identification and treatment of insomnia in patients with clinically stable schizophrenia.

The research was supported
by the Major Project of Chinese Brain Science and Brain-like Research (2021ZD0202102), the National Natural Science Foundation of China (31300848), and the International Cooperation Research Program of the Chinese Academy of Sciences (153111KYSB20190004).
The findings have been published online in Sleep and Breathing
.