Brain-derived neurotrophic factor (BDNF) is implicated in the etiology of schizophrenia, and peripheral BDNF levels are affected by the short-term antipsychotic treatment. However, the data on their long-term effects on BDNF levels are scarce, and there is no information whether BDNF levels change during sustained remission in relation to values in healthy individuals. The aim of the present study was to compare serum BDNF levels in patients in long-term remission and healthy controls. This study is an extension of our previous research on the effects of olanzapine and risperidone on serum BDNF in acute-episode patients with schizophrenia. Patients who remained in remission for at least 3 years on the same antipsychotic regimen (40 % of the initial cohort) were included. Symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS). Serum BDNF levels were measured by ELISA in patients in remission (N = 20), evaluated at baseline, after 6 weeks of treatment and after 3 years of treatment, and in healthy individuals (N = 40). At baseline (p = 0.046) and after 6 weeks of treatment (p = 0.028), patients had significantly lower BDNF levels than controls. However, after 3 years of continuous antipsychotic maintenance treatment, serum BDNF levels were increased compared to baseline and values after 6 weeks of treatment in remitted patients, and were also significantly higher in patients than in healthy controls (p = 0.002). Antipsychotic medications appear to have distinct effects on serum BDNF levels in short-and long-term treatment. It remains to be determined if such finding may be related to potential neuroprotective effects of antipsychotic maintenance treatment.

Emerging studies indicate that oxidative stress may contribute to deficit syndrome (DS) in patients with schizophrenia. Homocysteine (Hcy) is a well-known marker and mediator of oxidative stress that exhibits tight associations with schizophrenia. However, no previous studies have assessed the relationship of DS with Hcy. This study evaluated the prevalence, clinical characteristics, and association of DS with Hcy in 491 patients with schizophrenia. Plasma levels of Hcy and other metabolic parameters were measured. Positive and Negative Syndrome Scale and the proxy scale for deficit syndrome were employed to assess psychiatric symptoms and DS. The logistic regression model was conducted to assess independent factors associated with DS, and the Area Under the Curve (AUC) was used to assess the performance of our model. There was a high incidence of hyperhomocysteinemia (58.8%) and DS (24.4%). Plasma Hcy levels were significantly higher in patients with DS. Age, Hcy levels, and psychiatric symptoms were independently associated with DS. The combination of these variables perfectly differentiated DS and non-DS patients with an AUC value of 0.89. Our study suggests that elevated Hcy levels may be related to DS. Routine monitoring of Hcy is essential and may facilitate early detection of DS in patients with schizophrenia.

Schizophrenia patients show increased disabilities and lower quality of life (DisQoL). Nevertheless, there are no data on whether the activation of the interleukin (IL)-6, IL-23, T helper (Th)-17 axis, and lower magnesium and calcium levels impact DisQoL scores. This study recruited 90 patients with schizophrenia (including 40 with deficit schizophrenia) and 40 healthy controls and assessed the World Health Association QoL instrument-Abbreviated version and Sheehan Disability scale, Brief Assessment of Cognition in Schizophrenia (BACS), IL-6, IL-23, IL-17, IL-21, IL-22, tumor necrosis factor (TNF)-α, magnesium and calcium. Regression analyses showed that a large part of the first factor extracted from the physical, psychological, social and environmental HR-QoL and interference with school/work, social life, and home responsibilities was predicted by a generalized cognitive deterioration (G-CoDe) index (a latent vector extracted from BACs scores), and the first vector extracted from various symptom domains ("symptomatome"), whereas the biomarkers had no effects. Partial Least Squares analysis showed that the IL6IL23Th17 axis and magnesium/calcium had highly significant total (indirect + direct) effects on HR-QoL/disabilities, which were mediated by G-CoDe and the symptomatome (a first factor extracted from negative and positive symptoms). The IL6IL23Th17 axis explained 63.1% of the variance in the behavioral-cognitive-psycho-social (BCPS) worsening index a single latent trait extracted from G-CoDe, symptomatome, HR-QoL and disability data. In summary, the BCPS worsening index is partly caused by the neuroimmunotoxic effects of the IL6IL23Th17 axis in subjects with lowered antioxidant defenses (magnesium and calcium), thereby probably damaging the neuronal circuits that may underpin deficit schizophrenia.

The prevalence of glucolipid metabolic disorders (GLMDs) in children and adolescents has a recognized association with cardiovascular diseases and type 2 diabetes mellitus in adulthood. Therefore, it is important to enhance our under-standing of the risk factors for GLMD in childhood and adolescence.

To explore the relationship between quality of life (QoL) and adolescent GLMD.

This study included 1956 samples in 2019 from a cohort study established in 2014. The QoL scale and glycolipid indexes were collected during follow-up; other covariates of perinatal factors, physical measures, and socioeconomic indicators were collected and adjusted. A generalized linear regression model and logistic regression model were used to analyse the correlation between QoL and GLMD.

Higher scores of QoL activity opportunity, learning ability and attitude, attitude towards doing homework, and living convenience domains correlated negatively with insulin and homeostasis model assessment insulin resistance (IR) levels. Psychosocial factors, QoL satisfaction factors, and total QoL scores had significant protective effects on insulin and IR levels. Activity opportunity, learning ability and attitude, attitude towards doing homework domains of QoL, psychosocial factor, and total score of QoL correlated positively with high density lipoprotein. In addition, the attitude towards doing homework domain was a protective factor for dyslipidaemia, IR > 3, and increased fasting blood glucose; four factors, QoL and total QoL score correlated significantly negatively with IR > 3. In subgroup analyses of sex, more domains of QoL correlated with insulin and triglyceride levels, dyslipidaemia, and IR > 3 in females. Poor QoL was associated with an increased prevalence of GLMD, and the effect was more pronounced in males than in females. Measures to improve the QoL of adolescents are essential to reduce rates of GLMD.

Our study revealed that QoL scores mainly correlate negatively with the prevalence of GLMD in adolescents of the healthy population. The independent relationship between QoL and GLMD can be illustrated by adjusting for multiple covariates that may be associated with glycaemic index. In addition, among females, more QoL domains are associated with glycaemic index.