Objective To investigate effects of N-acetylcysteine (NAC) on changes of the behavior and the monoamine neurotransmitters in prefrontal cortex (PFC), striatum (ST), amygdala (AM) and hippocampus (HIP) in rat model of chronic unpredictable stress (CUS), and to explore the possible mechanisms related to the NAC. Methods Thirty-two male Sprague-Dawle (SD) rats were divided into CUS group, fluoxetine group (FLX), NAC group and control group (n=8 for each group). Rats in CUS group, NAC group and FLX group were all fed alone and received CUS for 6 weeks to establish CUS model. Rats in NAC group and FLX group were given NAC and FLX by daily intragastric administration respectively during the last 3 weeks, while rats in CUS group and control group were given the same volume of solvent. Behavioral assessment including weight measurement, sucrose water consumption test, and opened field test were used for evaluation before and after CUS, and before and after intervention. The concentrations of the monoamine neurotransmitters (NE, DA, 5-HT) in PFC, ST, AM and HIP were measured with Coul array HPLC. Results (1) There were more increases in weight gain, sucrose consumption, and distance of horizontal moving and number of up-right, while the number of feces was less, after intervention in control group, NAC group and FLX group than those of CUS group (P<0.05). (2) Neurotransmitters including NE, DA and 5-HT were significantly decreased in PFC, ST, AM and HIP in CUS group compared with that of control group (P<0.05). The monoamine neurotransmitter (NE, DA and 5-HT) were significantly increased in the brain region (PFC, ST, AM and HIP) in NAC group and FLX group than those of CUS group (P < 0.05). Conclusion NAC and fluoxetine can effectively improve the depressive behavior of the CUS rats, increase the contents of monoamine neurotransmitters including NE, DA and 5-HT in PFC, AM, ST and HIP brain regions.

Objective: Studies on duration of untreated psychosis are common in patients with schizophrenia, but few studies have investigated the relationship between duration of untreated illness (DUI) and suicide, especially in patients with chronic schizophrenia. Therefore, we intended to investigate the relationship between DUI and suicide and clinical correlates in patients with chronic schizophrenia. Methods: A total of 1,555 Chinese patients with chronic schizophrenia were enrolled in this study. DUI was measured in years, reflecting the prolonged untreated periods observed in this population. Clinical correlates were assessed, including symptoms, cognitive functioning, and body mass index. Suicidal ideation and attempts were also examined. Statistical analyses, including multivariate models, were employed to investigate the associations between DUI and clinical correlates while controlling for potential confounders. Results: The study revealed a significant proportion (23.3%) of patients with chronic schizophrenia in China received their first treatment after a 4-year delay, with the longest untreated duration reaching 39 years. Patients with longer DUI exhibited more severe negative symptoms, lower immediate memory scores, a higher likelihood of being overweight, and surprisingly, a reduced likelihood of suicidal ideation and attempts. Each additional year of untreated illness was associated with a 3% decrease in the risk of suicidal ideation and attempts. Conclusion The findings underscore the prevalence of extended untreated periods in Chinese patients with chronic schizophrenia and highlight the impact of DUI on negative symptoms, cognitive function, and body weight. Intriguingly, a longer DUI was associated with a lower risk of suicidal ideation and attempts.