Antipsychotic induced metabolic changes & treatment response: a prospective study

Clinical improvement in schizophrenia during antipsychotic treatment in relation to changes in glucose parameters: A systematic review

Antipsychotics (APs) are the cornerstone of treatment for schizophrenia (SCZ) spectrum disorders. Previous research suggests that there may be a positive association between AP-induced weight gain and/or dyslipidemia and improvement in psychiatric symptoms, often referred to as a "metabolic threshold". To determine whether a similar relationship exists for glucose parameters, we conducted a systematic search in six databases from inception to June 2022 for all longitudinal studies that directly examined the relationship between changes in glucose-related outcomes and changes in psychopathology among patients with SCZ treated with APs. We identified 10 relevant studies and one additional study that considered cognition. In most cases, we found that increased levels of fasting glucose and insulin following treatment were associated with clinical improvement. These findings contribute to existing literature that could suggest a common mechanism between AP action and metabolic side effects and support a need for additional work aimed at exploring the validity of a glucose-psychopathology relation in SCZ.

Eating cognitions, emotions and behaviour under treatment with second generation antipsychotics: A systematic review and meta-analysis

Weight gain and metabolic disturbances are frequent in people treated with second generation antipsychotics (SGA). We aimed to investigate the effect of SGAs on eating behaviors, cognitions and emotions, as a possible contributor to this adverse effect. A systematic review and a meta-analysis were conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Original articles measuring outcomes relating to eating cognitions, behaviours and emotions, during treatment with SGAs were included in this review. A total of 92 papers with 11,274 participants were included from three scientific databases (PubMed, Web of Science and PsycInfo). Results were synthesized descriptively except for the continuous data where meta-analyses were performed and for the binary data where odds ratios were calculated. Hunger was increased in participants treated with SGAs with an odds ratio for appetite increase of 1.51 (95% CI [1.04, 1.97]; z = 6.40; p < 0.001). Compared to controls, our results showed that craving for fat and carbohydrates are the highest among other craving subscales. There was a small increase in dietary disinhibition (SMD = 0.40) and restrained eating (SMD = 0.43) in participants treated with SGAs compared to controls and substantial heterogeneity across studies reporting these eating traits. There were few studies examining other eating-related outcomes such as food addiction, satiety, fullness, caloric intake and dietary quality and habits. Understanding the mechanisms associated with appetite and eating-related psychopathology changes in patients treated with antipsychotics is needed to reliably inform the development of effective preventative strategies.

Changes in the blood plasma lipidome associated with effective or poor response to atypical antipsychotic treatments in schizophrenia patients

Atypical antipsychotics are widely used to manage schizophrenia symptoms. However, these drugs can induce deleterious side effects, such as MetS, which are associated with an increased cardiovascular risk to patients. Lipids play a central role in this context, and changes in lipid metabolism have been implicated in schizophrenia's pathobiology. Furthermore, recent evidence suggests that lipidome changes may be related to antipsychotic treatment response. The aim of this study was to evaluate the lipidome changes in blood plasma samples of schizophrenia patients before and after 6 weeks of treatment with either risperidone, olanzapine, or quetiapine. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis showed changes in the levels of ceramides (Cer), glycerophosphatidic acids (PA), glycerophosphocholines (PC), phosphatidylethanolamines (PE), phosphatidylinositols (PI), glycerophosphoglycerols (PG), and phosphatidylserines (PS) for all treatments. However, the treatment with risperidone also affected diacylglycerides (DG), ceramide 1-phosphates (CerP), triglycerides (TG), sphingomyelins (SM), and ceramide phosphoinositols (PI-Cer). Moreover, specific lipid profiles were observed that could be used to distinguish poor and good responders to the different antipsychotics. As such, further work in this area may lead to lipid-based biomarkers that could be used to improve the clinical management of schizophrenia patients.

Association between Serum Lipids and Antipsychotic Response in Schizophrenia

Metabolic abnormalities are serious health problems in individuals with schizophrenia. Paradoxically, studies have noted an association where individuals who gained body weight or who have increased their serum lipids demonstrated a better antipsychotic response. As serum lipids serve as more specific physiological markers than body weight, the objective of this study was to review studies that examined the association between changes in serum lipids and changes in symptoms during antipsychotic treatment in individuals with schizophrenia. A Medline® literature search was performed. Fourteen studies were included and analyzed. Evidence suggests that increases in serum lipids may be associated with decreases in symptoms during antipsychotic treatment. This inverse association may be independent of confounding variables, such as weight gain, and may be most evident during treatment with clozapine. Also, according to recent randomized controlled trials, lipid-lowering agents do not appear to worsen symptoms although this needs to be further investigated in clozapine-treated patients. Future studies should investigate the association in question in a larger population and identify underlying mechanisms.

Genetic evidence for a role of the SREBP transcription system and lipid biosynthesis in schizophrenia and antipsychotic treatment

Schizophrenia is a serious psychotic disorder, with disabling symptoms and markedly reduced life expectancy. The onset is usually in late adolescence or early adulthood, which in time overlaps with the maturation of the brain including the myelination process. Interestingly, there seems to be a link between myelin abnormalities and schizophrenia. The oligodendrocyte-derived myelin membranes in the CNS are highly enriched for lipids (cholesterol, phospholipids and glycosphingolipids), thereby pointing at lipid homeostasis as a relevant target for studying the genetics and pathophysiology of schizophrenia. The biosynthesis of fatty acids and cholesterol is regulated by the sterol regulatory element binding protein (SREBP) transcription factors SREBP1 and SREBP2, which are encoded by the SREBF1 and SREBF2 genes on chromosome 17p11.2 and 22q13.2, respectively. Here we review the evidence for the involvement of SREBF1 and SREBF2 as genetic risk factors in schizophrenia and discuss the role of myelination and SREBP-mediated lipid biosynthesis in the etiology, pathophysiology and drug treatment of schizophrenia.