Polysomnographic features of insomnia occurring in major depressive disorder, generalized anxiety disorder and bipolar mania: Comparison with primary insomnia and association with metabolic indicators

Insomnia is very common in psychiatric disorders, but the polysomnographic (PSG) characteristics of insomnia in various psychiatric disorders are still not agreed upon. This study aimed to investigate the characteristics of PSG and its relationship with metabolic indicators in insomnia patients with affective disorders and primary insomnia (PI) patients.A total of 38 patients with PI, 44 major depressive disorder patients with insomnia (DI), 49 generalized anxiety disorder patients with insomnia (GI), and 19 bipolar mania patients with insomnia (BI) were included. PSG was used to detect sleep problems in subjects, and biochemical indicators were also collected.The results of this study found that subjects with BI were lower on REM sleep latency (RL), awakenings number (AN), number of microarousals (NM), and apnea-hypopnea index (AHI) than those with DI and GI, and lower on RL and AN than those with PI. Subjects with PI had lower NM and AHI than those with DI and GI. Patients with DI had a higher RL than those with GI. All results passed Bonferroni correction (p < 0.00078). No differences in biochemical indices were found among the four groups of subjects. Also, AHI was found to be positively correlated with free triiodothyronine (FT3) and fasting blood glucose in subjects.This study suggests that various psychiatric disorders may have their characteristics in terms of PSG parameters, which prompted us to focus on the PSG characteristics of these disorders when assessing them, as well as to focus on their biochemical indicators.