Olanzapine-induced hyperphagia and weight gain associate with orexigenic hypothalamic neuropeptide signaling without concomitant AMPK phosphorylation

Metabolic syndrome and its relation to antipsychotic polypharmacy in schizophrenia, schizoaffective and bipolar disorders

The risk of metabolic syndrome (MetS) has been attributed to antipsychotic use in psychiatric patients. To date, there is limited data on the relationship between antipsychotic polypharmacy and MetS in patients with schizophrenia, schizoaffective disorder and bipolar disorder. Therefore, we aimed to investigate the rate of MetS in patients with these disorders receiving antipsychotic monotherapy and polypharmacy. We conducted a cross-sectional study on patients seen between January 2017 and December 2020, collecting data on the class, type, route of administration and number of antipsychotics received. We used the American Association of Clinical Endocrinology criteria to diagnose MetS. We included 833 subjects of whom 573 (68.8%) received antipsychotic monotherapy and 260 (31.2%) received polypharmacy. Overall, 28.6% ( N  = 238) had MetS with no statistical difference between the two groups. Diastolic blood pressure and receiving olanzapine were significant predictors for developing MetS. In conclusion, our study found no significant difference in the rate of MetS between antipsychotic monotherapy and polypharmacy. A number of variables were significant predictors for MetS. Our findings were consistent with other studies and warrant the need for careful choice of antipsychotics and regular screening and management of abnormal metabolic parameters.

Aprepitant boasted a protective effect against olanzapine-induced metabolic syndrome and its subsequent hepatic, renal, and ovarian dysfunction; Role of IGF1/p-AKT/FOXO1 and NFκB/IL-1β/TNF-α signaling pathways in female Wistar albino rats

Olanzapine-induced metabolic syndrome (MS) is a primary risk factor for insulin resistance, hepatorenal damage, and polycystic ovarian syndrome. The objective of the current study was to assess the protective effects of aprepitant (AP) against MS caused by olanzapine and the associated ovarian, renal, and liver dysfunction via modulation of IGF1/p-AKT/FOXO1 and NFκB/IL-1β/TNF-α signaling pathways. AP mitigated all biochemical and histopathological abnormalities induced by olanzapine and resulted in a significant reduction of serum HOMA-IR, lipid profile parameters, and a substantial decrease in hepatic, renal, and ovarian MDA, IL-6, IL-1β, TNF-α, NFκB, and caspase 3. Serum AST, ALT, urea, creatinine, FSH, LH, and testosterone also decreased significantly by AP administration. The FOXO 1 signaling pathway was downregulated in the AP-treated group, while GSH, SOD, and HDL cholesterol levels were elevated.

Olanzapine, risperidone and ziprasidone differently affect lysosomal function and autophagy, reflecting their different metabolic risk in patients

The metabolic effects induced by antipsychotics in vitro depend on their action on the trafficking and biosynthesis of sterols and lipids. Previous research showed that antipsychotics with different adverse effects in patients cause similar alterations in vitro, suggesting the low clinical usefulness of cellular studies. Moreover, the inhibition of peripheral AMPK was suggested as potential aetiopathogenic mechanisms of olanzapine, and different effects on autophagy were reported for several antipsychotics. We thus assessed, in clinically-relevant culture conditions, the aetiopathogenic mechanisms of olanzapine, risperidone and ziprasidone, antipsychotics with respectively high, medium, low metabolic risk in patients, finding relevant differences among them. We highlighted that: olanzapine impairs lysosomal function affecting autophagy and autophagosome clearance, and increasing intracellular lipids and sterols; ziprasidone activates AMPK increasing the autophagic flux and reducing intracellular lipids; risperidone increases lipid accumulation, while it does not affect lysosomal function. These in vitro differences align with their different impact on patients. We also provided evidence that metformin add-on improved autophagy in olanzapine-treated cells and reduced lipid accumulation induced by both risperidone and olanzapine in an AMPK-dependent way; metformin also increased the production of bile acids to eliminate cholesterol accumulations caused by olanzapine. These results have different clinical implications. We demonstrated that antipsychotics with different metabolic impacts on patients actually have different mechanisms of action, thus supporting the possibility of a personalised antipsychotic treatment. Moreover, we found that metformin can fully revert the phenotype caused by risperidone but not the one caused by olanzapine, that still activates SREBP2.

Metabolic effects of atypical antipsychotics: Molecular targets

Atypical antipsychotics (AAPs) are commonly prescribed drugs in the treatment of schizophrenia, bipolar disorder and other mental diseases with psychotic traits. Although the use of AAPs is associated with beneficial effects in these patients, they are also associated with undesired metabolic side effects, including metabolic syndrome (MetS). MeS is defined by the presence of metabolic abnormalities such as large waist circumference, dyslipidemia, fasting hyperglycemia and elevated blood pressure, which predispose to type 2 diabetes (T2D) and cardiovascular disease. In this review, the molecular and cellular mechanisms involved in these undesired metabolic abnormalities induced by AAPs are described. These mechanisms are complex as AAPs have multiple cellular targets which significantly affect the activities of several hormones and neuromodulators. Additionally, AAPs affect all the relevant metabolic organs, namely the liver, pancreas, adipose tissue, skeletal muscle and intestine, and the central and peripheral nervous system as well. A better understanding of the molecular targets linking AAPs with MetS and of the mechanisms responsible for clinically different side effects of distinct AAPs is needed. This knowledge will help in the development of novel AAPs with less adverse effects as well as of adjuvant therapies to patients receiving AAPs.

Targeting Clic1 for the treatment of obesity: A novel therapeutic strategy to reduce food intake and body weight

OBJECTIVE

Despite great advances in obesity therapeutics in recent years, there is still a need to identify additional therapeutic targets for the treatment of this disease. We previously discovered a signature of genes, including Chloride intracellular channel 1 (Clic1), whose expression was associated with drug-induced weight gain, and in these studies, we assess the effect of Clic1 inhibition on food intake and body weight in mice.

METHODS

We studied the impact of Clic1 inhibition in mouse models of binge-eating, diet-induced obese mice and genetic models of obesity (Magel2 KO mice).

RESULTS

Clic1 knockout (KO) mice ate significantly less and had a lower body weight than WT littermates when either fed chow or high fat diet. Furthermore, pharmacological inhibition of Clic1 in diet-induced obese mice resulted in suppression of food intake and promoted highly efficacious weight loss. Clic1 inhibition also reduced food intake in binge-eating models and hyperphagic Magel2 KO mice. We observed that chronic obesity resulted in a significant change in subcellular localization of Clic1 with an increased ratio of Clic1 in the membrane in the obese state. These observations provide a novel therapeutic strategy to block Clic1 translocation as a potential mechanism to reduce food intake and lower body weight.

CONCLUSIONS

These studies attribute a novel role of Clic1 as a driver of food intake and overconsumption. In summary, we have identified hypothalamic expression of Clic1 plays a key role in food intake, providing a novel therapeutic target to treat overconsumption that is the root cause of modern obesity.

Changes in hypothalamic mu-opioid receptor expression following acute olanzapine treatment in female rats: Implications for feeding behavior

Advances have been made in recent years in using opioid receptor antagonists as an adjunct therapy to psychotropic medication to reduce debilitating weight gain and metabolic adverse effects associated with in particular second generation antipsychotics. However, it is unknown whether second generation antipsychotics produce a change in opioid receptor expression in the brain. The present study investigated early changes in opioid receptor expression in the female rat hypothalamus, a master controller of hunger and metabolic regulation, after acute treatment with olanzapine, a commonly used second generation antipsychotic. Using quantitative spatial in situ hybridization and receptor autoradiography, expression levels of the three opioid receptors; kappa, mu and delta, were determined at mRNA and protein level, respectively, in the five hypothalamic areas: paraventricular nucleus, arcuate nucleus, ventromedial nucleus, dorsomedial nucleus and lateral hypothalamus. After 48 h of olanzapine treatment at clinically relevant plasma concentration weight gain and food intake changes, and increased plasma glucose were observed in female rats. Olanzapine treatment also led to a significant increase in mu opioid receptor availability in the arcuate nucleus, which contains both satiety and hunger controlling neurons. No other areas showed any opioid receptor expressional changes with olanzapine treatment on neither at mRNA nor protein level. Technical difficulties made it impossible to analyze mRNA levels in the lateral hypothalamus and overall binding of delta opioid receptors. Thus, the present study provided insights in to how olanzapine at clinically relevant plasma levels already at an early stage modulated the opioid system in the hypothalamus.

The Use of Phentermine for Obesity in Psychiatric Patients With Antipsychotics

OBJECTIVE

Phentermine is a commonly used weight-loss agent in the United States, but there is a little information about the use of phentermine for patients with obesity taking antipsychotic medications.

METHODS

We gathered 57 patients with obesity taking antipsychotic medications whose phentermine treatment was simultaneous with or after any type of antipsychotic exposure and collected data of clinical information, initial/follow-up anthropometric variables, and adverse events (AEs) for the 6-month study period.

RESULTS

In total, the mean body weight reduction (BWR) was 4.45 (7.04) kg, and the mean BWR percent (BWR%) was 3.92% (6.96%) at 6 months. Based on the response to phentermine, the patients were classified into two groups: the responder (n=25; BWR% ≥5%) and nonresponder (n=32; BWR% <5%) groups. The responder group's mean BWR and BWR% were 10.13 (4.43) kg and 9.35% (4.09%), respectively, at 6 months. The responders had higher rates of anticonvulsant combination therapy (ACT; responder, 72.0% vs. non-responder, 43.8%; p=0.033) and a shorter total antipsychotic exposure duration (responder, 23.9 [16.9] months vs. non-responder, 37.2 [27.6] months; p= 0.039). After adjusting age, sex, and initial body weight, ACT maintained a significant association with phentermine response (odds ratio=3.840; 95% confidence interval: 1.082-13.630; p=0.037). In the final cohort, there was no report of adverse or new-onset psychotic symptoms, and the common AEs were sleep disturbances, dry mouth, and dizziness.

CONCLUSION

Overall, phentermine was effective and tolerable for patients with obesity taking antipsychotic medications, and ACT (predominantly topiramate) augmented the weight-loss effect of phentermine.

Nuclear receptor 5A2 regulation of Agrp underlies olanzapine-induced hyperphagia

Antipsychotic (AP) drugs are efficacious treatments for various psychiatric disorders, but excessive weight gain and subsequent development of metabolic disease remain serious side effects of their use. Increased food intake leads to AP-induced weight gain, but the underlying molecular mechanisms remain unknown. In previous studies, we identified the neuropeptide Agrp and the transcription factor nuclear receptor subfamily 5 group A member 2 (Nr5a2) as significantly upregulated genes in the hypothalamus following AP-induced hyperphagia. While Agrp is expressed specifically in the arcuate nucleus of the hypothalamus and plays a critical role in appetite stimulation, Nr5a2 is expressed in both the CNS and periphery, but its role in food intake behaviors remains unknown. In this study, we investigated the role of hypothalamic Nr5a2 in AP-induced hyperphagia and weight gain. In hypothalamic cell lines, olanzapine treatment resulted in a dose-dependent increase in gene expression of Nr5a2 and Agrp. In mice, the pharmacological inhibition of NR5A2 decreased olanzapine-induced hyperphagia and weight gain, while the knockdown of Nr5a2 in the arcuate nucleus partially reversed olanzapine-induced hyperphagia. Chromatin-immunoprecipitation studies showed for the first time that NR5A2 directly binds to the Agrp promoter region. Lastly, the analysis of single-cell RNA seq data confirms that Nr5a2 and Agrp are co-expressed in a subset of neurons in the arcuate nucleus. In summary, we identify Nr5a2 as a key mechanistic driver of AP-induced food intake. These findings can inform future clinical development of APs that do not activate hyperphagia and weight gain.

Modulation of hypothalamic AMPK phosphorylation by olanzapine controls energy balance and body weight

BACKGROUND

Second-generation antipsychotics (SGAs) are a mainstay therapy for schizophrenia. SGA-treated patients present higher risk for weight gain, dyslipidemia and hyperglycemia. Herein, we evaluated the effects of olanzapine (OLA), widely prescribed SGA, in mice focusing on changes in body weight and energy balance. We further explored OLA effects in protein tyrosine phosphatase-1B deficient (PTP1B-KO) mice, a preclinical model of leptin hypersensitivity protected against obesity.

METHODS

Wild-type (WT) and PTP1B-KO mice were fed an OLA-supplemented diet (5 mg/kg/day, 7 months) or treated with OLA via intraperitoneal (i.p.) injection or by oral gavage (10 mg/kg/day, 8 weeks). Readouts of the crosstalk between hypothalamus and brown or subcutaneous white adipose tissue (BAT and iWAT, respectively) were assessed. The effects of intrahypothalamic administration of OLA with adenoviruses expressing constitutive active AMPKα1 in mice were also analyzed.

RESULTS

Both WT and PTP1B-KO mice receiving OLA-supplemented diet presented hyperphagia, but weight gain was enhanced only in WT mice. Unexpectedly, all mice receiving OLA via i.p. lost weight without changes in food intake, but with increased energy expenditure (EE). In these mice, reduced hypothalamic AMPK phosphorylation concurred with elevations in UCP-1 and temperature in BAT. These effects were also found by intrahypothalamic OLA injection and were abolished by constitutive activation of AMPK in the hypothalamus. Additionally, OLA i.p. treatment was associated with enhanced Tyrosine Hydroxylase (TH)-positive innervation and less sympathetic neuron-associated macrophages in iWAT. Both central and i.p. OLA injections increased UCP-1 and TH in iWAT, an effect also prevented by hypothalamic AMPK activation. By contrast, in mice fed an OLA-supplemented diet, BAT thermogenesis was only enhanced in those lacking PTP1B. Our results shed light for the first time that a threshold of OLA levels reaching the hypothalamus is required to activate the hypothalamus BAT/iWAT axis and, therefore, avoid weight gain.

CONCLUSION

Our results have unraveled an unexpected metabolic rewiring controlled by hypothalamic AMPK that avoids weight gain in male mice treated i.p. with OLA by activating BAT thermogenesis and iWAT browning and a potential benefit of PTP1B inhibition against OLA-induced weight gain upon oral treatment.

Non-alcoholic fatty liver disease (NAFLD) and mental illness: Mechanisms linking mood, metabolism and medicines

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the world and one of the leading indications for liver transplantation. It is one of the many manifestations of insulin resistance and metabolic syndrome as well as an independent risk factor for cardiovascular disease. There is growing evidence linking the incidence of NAFLD with psychiatric illnesses such as schizophrenia, bipolar disorder and depression mechanistically via genetic, metabolic, inflammatory and environmental factors including smoking and psychiatric medications. Indeed, patients prescribed antipsychotic medications, regardless of diagnosis, have higher incidence of NAFLD than population norms. The mechanistic pharmacology of antipsychotic-associated NAFLD is beginning to emerge. In this review, we aim to discuss the pathophysiology of NAFLD including its risk factors, insulin resistance and systemic inflammation as well as its intersection with psychiatric illnesses.

Metformin ameliorates olanzapine-induced obesity and glucose intolerance by regulating hypothalamic inflammation and microglial activation in female mice

Olanzapine (OLZ), a widely used second-generation antipsychotic drug, is known to cause metabolic side effects, including diabetes and obesity. Interestingly, OLZ-induced metabolic side effects have been demonstrated to be more profound in females in human studies and animal models. Metformin (MET) is often used as a medication for the metabolic side effects of OLZ. However, the mechanisms underlying OLZ-induced metabolic disturbances and their treatment remain unclear. Recent evidence has suggested that hypothalamic inflammation is a key component of the pathophysiology of metabolic disorders. On this background, we conducted this study with the following three objectives: 1) to investigate whether OLZ can independently induce hypothalamic microgliosis; 2) to examine whether there are sex-dependent differences in OLZ-induced hypothalamic microgliosis; and 3) to examine whether MET affects hypothalamic microgliosis. We found that administration of OLZ for 5 days induced systemic glucose intolerance and hypothalamic microgliosis and inflammation. Of note, both hypothalamic microglial activation and systemic glucose intolerance were far more evident in female mice than in male mice. The administration of MET attenuated hypothalamic microglial activation and prevented OLZ-induced systemic glucose intolerance and hypothalamic leptin resistance. Minocycline, a tetracycline derivative that prevents microgliosis, showed similar results when centrally injected. Our findings reveal that OLZ induces metabolic disorders by causing hypothalamic inflammation and that this inflammation is alleviated by MET administration.

The role of hypothalamic endoplasmic reticulum stress in schizophrenia and antipsychotic-induced weight gain: A narrative review

Schizophrenia (SCZ) is a serious mental illness that affects 1% of people worldwide. SCZ is associated with a higher risk of developing metabolic disorders such as obesity. Antipsychotics are the main treatment for SCZ, but their side effects include significant weight gain/obesity. Despite extensive research, the underlying mechanisms by which SCZ and antipsychotic treatment induce weight gain/obesity remain unclear. Hypothalamic endoplasmic reticulum (ER) stress is one of the most important pathways that modulates inflammation, neuronal function, and energy balance. This review aimed to investigate the role of hypothalamic ER stress in SCZ and antipsychotic-induced weight gain/obesity. Preliminary evidence indicates that SCZ is associated with reduced dopamine D2 receptor (DRD2) signaling, which significantly regulates the ER stress pathway, suggesting the importance of ER stress in SCZ and its related metabolic disorders. Antipsychotics such as olanzapine activate ER stress in hypothalamic neurons. These effects may induce decreased proopiomelanocortin (POMC) processing, increased neuropeptide Y (NPY) and agouti-related protein (AgRP) expression, autophagy, and leptin and insulin resistance, resulting in hyperphagia, decreased energy expenditure, and central inflammation, thereby causing weight gain. By activating ER stress, antipsychotics such as olanzapine activate hypothalamic astrocytes and Toll-like receptor 4 signaling, thereby causing inflammation and weight gain/obesity. Moreover, evidence suggests that antipsychotic-induced ER stress may be related to their antagonistic effects on neurotransmitter receptors such as DRD2 and the histamine H1 receptor. Taken together, ER stress inhibitors could be a potential effective intervention against SCZ and antipsychotic-induced weight gain and inflammation.

A systematic review of licensed weight-loss medications in treating antipsychotic-induced weight gain and obesity in schizophrenia and psychosis

BACKGROUND

Schizophrenia and antipsychotic use are associated with clinically significant weight gain and subsequent increased mortality. Despite weight loss medications (WLMs) licensed by regulatory bodies (FDA, EMA, and MHRA) being available, current psychiatric guidelines recommend off-label alternatives, which differ from non-psychiatric guidelines for obesity.

OBJECTIVE

Evaluate the efficacy of licensed WLMs on treating antipsychotic-induced weight gain (AIWG) and obesity in schizophrenia and psychosis (OSP).

METHOD

A literature search was conducted using Medline, EMBASE, PsycINFO and Cochrane Library online databases for human studies using licensed WLMs to treat AIWG and OSP.

RESULTS

Three RCTs (two liraglutide, one naltrexone-bupropion), one unpublished open-label trial (naltrexone-bupropion), and seven observational studies (five liraglutide, one semaglutide, one multiple WLMs) were identified. Results for liraglutide showed statistically significant improvement in weight, BMI, waist circumference, HbA1c, cholesterol, and LDL readings on meta-analysis. Evidence was mixed for naltrexone-bupropion with no detailed studies conducted for setmelanotide, or stimulants.

CONCLUSION

Evidence is strongest for liraglutide compared to other licensed WLMs. The findings, particularly the inclusion of human trial data, provide evidence for liraglutide use in treating AIWG and OSP, which would better align psychiatric practice with non-psychiatric practices around obesity. The findings also identify continued literature gaps regarding other licensed WLMs.

Metformin ameliorates olanzapine-induced disturbances in POMC neuron number, axonal projection, and hypothalamic leptin resistance

Antipsychotics have been widely accepted as a treatment of choice for psychiatric illnesses such as schizophrenia. While atypical antipsychotics such as aripiprazole are not associated with obesity and diabetes, olanzapine is still widely used based on the anticipation that it is more effective in treating severe schizophrenia than aripiprazole, despite its metabolic side effects. To address metabolic problems, metformin is widely prescribed. Hypothalamic proopiomelanocortin (POMC) neurons have been identified as the main regulator of metabolism and energy expenditure. Although the relation between POMC neurons and metabolic disorders is well established, little is known about the effects of olanzapine and metformin on hypothalamic POMC neurons. In the present study, we investigated the effect of olanzapine and metformin on the hypothalamic POMC neurons in female mice. Olanzapine administration for 5 days significantly decreased Pomc mRNA expression, POMC neuron numbers, POMC projections, and induced leptin resistance before the onset of obesity. It was also observed that coadministration of metformin with olanzapine not only increased POMC neuron numbers and projections but also improved the leptin response of POMC neurons in the olanzapine-treated female mice. These findings suggest that olanzapine-induced hypothalamic POMC neuron abnormality and leptin resistance, which can be ameliorated by metformin administration, are the possible causes of subsequent hyperphagia.

Gold nanoclusters eliminate obesity induced by antipsychotics

Obesity induced by antipsychotics have plagued more than 20 million people worldwide. However, no drug is available to eliminate the obesity induced by antipsychotics. Here we examined the effect and potential mechanisms of a gold nanoclusters (AuNCs) modified by N-isobutyryl-L-cysteine on the obesity induced by olanzapine, the most prescribed but obesogenic antipsychotics, in a rat model. Our results showed that AuNCs completely prevented and reversed the obesity induced by olanzapine and improved glucose metabolism profile in rats. Further mechanism investigations revealed that AuNCs exert its anti-obesity function through inhibition of olanzapine-induced dysfunction of histamine H1 receptor and proopiomelanocortin signaling therefore reducing hyperphagia, and reversing olanzapine-induced inhibition of uncoupling-protein-1 signaling which increases thermogenesis. Together with AuNCs' good biocompatibility, these findings not only provide AuNCs as a promising nanodrug candidate for treating obesity induced by antipsychotics, but also open an avenue for the potential application of AuNCs-based nanodrugs in treating general obesity.

The Case for Clinical Trials with Novel GABAergic Drugs in Diabetes Mellitus and Obesity

Obesity and diabetes mellitus have become the surprising menaces of relative economic well-being worldwide. Gamma amino butyric acid (GABA) has a prominent role in the control of blood glucose, energy homeostasis as well as food intake at several levels of regulation. The effects of GABA in the body are exerted through ionotropic GABAA and metabotropic GABAB receptors. This treatise will focus on the pharmacologic targeting of GABAA receptors to reap beneficial therapeutic effects in diabetes mellitus and obesity. A new crop of drugs selectively targeting GABAA receptors has been under investigation for efficacy in stroke recovery and cognitive deficits associated with schizophrenia. Although these trials have produced mixed outcomes the compounds are safe to use in humans. Preclinical evidence is summarized here to support the rationale of testing some of these compounds in diabetic patients receiving insulin in order to achieve better control of blood glucose levels and to combat the decline of cognitive performance. Potential therapeutic benefits could be achieved (i) By resetting the hypoglycemic counter-regulatory response; (ii) Through trophic actions on pancreatic islets, (iii) By the mobilization of antioxidant defence mechanisms in the brain. Furthermore, preclinical proof-of-concept work, as well as clinical trials that apply the novel GABAA compounds in eating disorders, e.g., olanzapine-induced weight-gain, also appear warranted.

Understanding the Effects of Antipsychotics on Appetite Control

Antipsychotic drugs (APDs) represent a cornerstone in the treatment of schizophrenia and other psychoses. The effectiveness of the first generation (typical) APDs are hampered by so-called extrapyramidal side effects, and they have gradually been replaced by second (atypical) and third-generation APDs, with less extrapyramidal side effects and, in some cases, improved efficacy. However, the use of many of the current APDs has been limited due to their propensity to stimulate appetite, weight gain, and increased risk for developing type 2 diabetes and cardiovascular disease in this patient group. The mechanisms behind the appetite-stimulating effects of the various APDs are not fully elucidated, partly because their diverse receptor binding profiles may affect different downstream pathways. It is critical to identify the molecular mechanisms underlying drug-induced hyperphagia, both because this may lead to the development of new APDs, with lower appetite-stimulating effects but also because such insight may provide new knowledge about appetite regulation in general. Hence, in this review, we discuss the receptor binding profile of various APDs in relation to the potential mechanisms by which they affect appetite.

Disordered Eating among People with Schizophrenia Spectrum Disorders: A Systematic Review

Disordered eating, or abnormal eating behaviours that do not meet the criteria for an independent eating disorder, have been reported among people with schizophrenia. We aimed to systemati-cally review literature on disordered eating among people with schizophrenia spectrum disorder (SSD). Seven databases were systematically searched for studies that described the prevalence and correlates of disordered eating among patients with SSD from January 1984 to 15 February 2021. Qualitative analysis was performed using the National Institutes of Health scales. Of 5504 records identified, 31 studies involving 471,159 subjects were included in the systematic review. The ma-jority of studies (17) rated fair on qualitative analysis and included more men, and participants in their 30s and 40s, on antipsychotics. The commonest limitations include lack of sample size or power calculations, poor sample description, not using valid tools, or not adjusting for con-founders. The reported rates were 4.4% to 45% for binge eating, 16.1% to 64%, for food craving, 27% to 60.6% for food addiction, and 4% to 30% for night eating. Positive associations were re-ported for binge eating with antipsychotic use and female gender, between food craving and weight gain, between food addiction and increased dietary intake, and between disordered eating and female gender, mood and psychotic symptoms. Reported rates for disordered eating among people with SSD are higher than those in the general population. We will discuss the clinical, treatment and research implications of our findings.

Abnormalities in Glucose Blood Level during Antipsychotic Treatment in Schizophrenia Patients

Background: Schizophrenia is one of the mental disorder with many problematic issues, in both psychologically and socially. This disease requires provision of long-term antipsychotic therapy, hence could rise other potential health problems. Antipsychotic treatment can cause serious glucometabolic side-effects, including type 2 diabetes and hyperglycemic emergency. Recent attention has also been focused on antipsychotic-induced hyperglycemic emergencies experienced by new users of typical and atypical antipsychotic. Patients treated with atypical APDs have ~10 times higher risk in developing hyperglycaemic emergencies. In our pre-eliminary study, hyperglycemia condition in new patients occurs in four  in seven patients who received typical and atypical antipsychotics. This condition is often overlooked and is not routinely evaluated. Moreover, it can develop into diabetes and increase the risk of morbidity and mortality in schizophrenia patients. In this study, we would like to determine the acute effects of metabolic (hyperglycemia) in patients treated with antipsychotic (Risperidone and Haloperidol) Measurement of blood sugar levels was performed in groups treated with haloperidol (N = 15) and treated with risperidone (N = 15). Plasma samples were taken at the beginning of treatment, in week IV, and in week VIII. The measurement of glucose levels was performed after meal and in early morning before breakfast (fasting blood glucose level 8 hours). Results: The blood sugar level after meals was significantly higher in the Risperidone group compared to the Haloperidol group  (p <0.001) after IV and VIII weeks. Meanwhile, the fasting blood sugar level was significantly higher in the Risperidone group compared to the Haloperidol group after VIII weeks of treatment ( p <0.001). Conclusions: Both antipsychotics can cause an increase in blood sugar levels. Treatment with Risperidone significantly increased the blood sugar levels compared to treatment with haloperidol. Measurement of blood sugar level is needed to monitor the metabolic effect of antipsychotic, especially in patients treated with Risperidone. It is necessary to have dietary regulation and physical activities to prevent undesired metabolic side effects.

The relationship between brain-derived neurotrophic factor and metabolic syndrome in patients with chronic schizophrenia: A systematic review

BACKGROUND & AIMS

Schizophrenia is a serious long-term disorder in which the metabolic complications and abnormalities of the brain-derived neurotrophic factor (BDNF) can be found. In this study, we conducted a systematic review of the relationship between BDNF, metabolic syndrome (MetS) and its components in schizophrenic patients.

METHODS

Data were collected mainly from PubMed, Google Scholar, Scopus, and ProQuest databases. The keywords related to the BDNF, MetS, schizophrenia were searched. Two reviewers independently screened 1061 abstracts. And eventually, a total of 7 studies (6 observational and 1 interventional) was included in the systematic reviews.

RESULTS

Four of the 7 study ascertained statistically significant inverse relationship between serum BDNF levels and MetS in schizophrenic patients. While in the other two studies, there was no inverse relationship. In the last selected study, the researchers found a weak association between the Val66Met polymorphism in BDNF Gene and clozapine-induced MetS.

CONCLUSION

Although this relationship could not be determined but BDNF levels appear to be reduced in schizophrenic patients with MetS and factors such as sex and antipsychotic class differentiation, sampling and methodology and episodes of illness could play a role in the results and outcomes.

Empagliflozin Effectively Attenuates Olanzapine-Induced Body Weight Gain in Female Wistar Rats

Atypical antipsychotic drugs are commonly associated with undesirable side effects including body weight gain (BWG) and metabolic deficits. Many pharmacological interventions have been tested in an attempt to minimize or prevent these side effects. Preliminary evidence suggests that antidiabetic drugs may be effective in attenuating antipsychotic-induced BWG. In the current study, we examined the effect of an antidiabetic drug empagliflozin (EMPA) on BWG induced by anatypical antipsychotic drug olanzapine (Ola) in female and male Wistar rats. Rats were divided into six groups based on the dose they received: group 1 (female control), group 2 (female EMPA, 20 mg/kg; IG), group 3 (female Ola, 4 mg/kg; IP), group 4 (female Ola, 4 mg/kg; IP + EMPA, 20 mg/kg; IG), group 5 (male control), and group 6 (male Ola, 4 mg/kg; IP). Ola induced sustained increase in BWG. The subsequent treatment of Group 3 and 4 with EMPA attenuated the Ola-induced BWG in female Wistar rats. In terms of the gender difference between female and male Wistar rats, the male control group 5 gained more weight throughout the study as compared to the female control group 1. Similarly, the male Ola group 6 gained more weight throughout the study as compared to the female Ola group 3. However, Ola did not cause any weight difference between male rats treated with Ola in comparison with male control group, thus showing a significant gender difference regarding body weight between male and female Wistar rats regardless of Ola administration. In addition, the present findings showed that EMPA effectively attenuates the Ola induced BWG in female Wistar rats. These novel findings should help to better understand the underlying molecular and behavioral mechanisms contributing to the observed increase in body weight after treatment with Ola and other atypical antipsychotic drugs across male and female rats.

Atypical Antipsychotics and Metabolic Syndrome: From Molecular Mechanisms to Clinical Differences

Atypical antipsychotics (AAPs) are commonly prescribed medications to treat schizophrenia, bipolar disorders and other psychotic disorders. However, they might cause metabolic syndrome (MetS) in terms of weight gain, dyslipidemia, type 2 diabetes (T2D), and high blood pressure, which are responsible for reduced life expectancy and poor adherence. Importantly, there is clear evidence that early metabolic disturbances can precede weight gain, even if the latter still remains the hallmark of AAPs use. In fact, AAPs interfere profoundly with glucose and lipid homeostasis acting mostly on hypothalamus, liver, pancreatic β-cells, adipose tissue, and skeletal muscle. Their actions on hypothalamic centers via dopamine, serotonin, acetylcholine, and histamine receptors affect neuropeptides and 5'AMP-activated protein kinase (AMPK) activity, thus producing a supraphysiological sympathetic outflow augmenting levels of glucagon and hepatic glucose production. In addition, altered insulin secretion, dyslipidemia, fat deposition in the liver and adipose tissues, and insulin resistance become aggravating factors for MetS. In clinical practice, among AAPs, olanzapine and clozapine are associated with the highest risk of MetS, whereas quetiapine, risperidone, asenapine and amisulpride cause moderate alterations. The new AAPs such as ziprasidone, lurasidone and the partial agonist aripiprazole seem more tolerable on the metabolic profile. However, these aspects must be considered together with the differences among AAPs in terms of their efficacy, where clozapine still remains the most effective. Intriguingly, there seems to be a correlation between AAP's higher clinical efficacy and increase risk of metabolic alterations. Finally, a multidisciplinary approach combining psychoeducation and therapeutic drug monitoring (TDM) is proposed as a first-line strategy to avoid the MetS. In addition, pharmacological treatments are discussed as well.

Effect of liraglutide on neural and peripheral markers of metabolic function during antipsychotic treatment in rats

BACKGROUND

Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that prevents metabolic side effects of the antipsychotic drugs (APDs) olanzapine and clozapine through unknown mechanisms.

AIM

This study aimed to investigate the effect of chronic APD and liraglutide co-treatment on key neural and peripheral metabolic signals, and acute liraglutide co-treatment on clozapine-induced hyperglycaemia.

METHODS

In study 1, rats were administered olanzapine (2 mg/kg), clozapine (12 mg/kg), liraglutide (0.2 mg/kg), olanzapine + liraglutide co-treatment, clozapine + liraglutide co-treatment or vehicle for six weeks. Feeding efficiency was examined weekly. Examination of brain tissue (dorsal vagal complex (DVC) and mediobasal hypothalamus (MBH)), plasma metabolic hormones and peripheral (liver and kidney) cellular metabolism and oxidative stress was conducted. In study 2, rats were administered a single dose of clozapine (12 mg/kg), liraglutide (0.4 mg/kg), clozapine + liraglutide co-treatment or vehicle. Glucose tolerance and plasma hormone levels were assessed.

RESULTS

Liraglutide co-treatment prevented the time-dependent increase in feeding efficiency caused by olanzapine, which plateaued by six weeks. There was no effect of chronic treatment on melanocortinergic, GABAergic, glutamatergic or endocannabionoid markers in the MBH or DVC. Peripheral hormones and cellular metabolic markers were unaltered by chronic APD treatment. Acute liraglutide co-treatment was unable to prevent clozapine-induced hyperglycaemia, but it did alter catecholamine levels.

CONCLUSION

The unexpected lack of change to central and peripheral markers following chronic treatment, despite the presence of weight gain, may reflect adaptive mechanisms. Further studies examining alterations across different time points are required to continue to elucidate the mechanisms underlying the benefits of liraglutide on APD-induced metabolic side effects.

Standardizing the Effective Correlated Dosage of Olanzapine and Empagliflozin in Female Wistar Rats

AIM

The primary aim of this study was to standardize the correlated effective dosage of the antidiabetic drug empagliflozin (EMPA) and the antipsychotic drug olanzapine (Ola).

BACKGROUND

Atypical antipsychotics are associated with BWG and metabolic disturbances for which many approaches have been used to minimize these issues, including antidiabetic drugs. The antidiabetic drugs have been quite effective in reversing BWG induced by the administration of antipsychotic drugs in patients who have psychosis, schizophrenia and bipolar disorder.

OBJECTIVE

The objective of this study was to standardize the correlated effective dosage of EMPA and Ola.

METHODS

The study was carried out for 28 days to represent the chronic effect of Ola on female Wistar rats. Rats were divided into three groups based on the dose they received: control (vehicle), Ola-4 and Ola-8 (4 and 8 mg/kg/OD, respectively), and EMPA-10 and EMPA-20 (10 and 20 mg/kg/OD, respectively).

RESULTS

Both doses of Ola produced a significant increase in the percentage of BWG, however, Ola-4 produced a higher BWG. Also, both the doses of EMPA were able to reverse the effect of Ola-induced BWG; however, EMPA-20 produced a higher reversal in BWG and normalized the rat's body weight.

CONCLUSION

We conclude that Ola-4 and EMPA-20 were the most effective dosage for experimental purposes in female Wistar rats. The findings of this study standardized the effective correlated dosage of olanzapine and empagliflozin in female Wistar rats that will help understand the underlying molecular and behavioral mechanisms.

Olanzapine-Induced Activation of Hypothalamic Astrocytes and Toll-Like Receptor-4 Signaling via Endoplasmic Reticulum Stress Were Related to Olanzapine-Induced Weight Gain

The antipsychotic drug olanzapine is associated with serious obesity side effects. Hypothalamic astrocytes and associated toll-like receptor-4 (TLR4) signaling play an essential role in obesity pathogenesis. This study investigated the effect of olanzapine on astrocytes and TLR4 signaling both in vitro and in the rat hypothalamus and their potential role in olanzapine-induced weight gain. We found that olanzapine treatment for 24 h dose-dependently increased cell viability, increased the protein expression of astrocyte markers including glial fibrillary acidic protein (GFAP) and S100 calcium binding protein B (S100B), and activated TLR4 signaling in vitro. In rats, 8- and 36-day olanzapine treatment caused weight gain accompanied by increased GFAP and S100B protein expression and activated TLR4 signaling in the hypothalamus. These effects still existed in pair-fed rats, suggesting that these effects were not secondary effects of olanzapine-induced hyperphagia. Moreover, treatment with an endoplasmic reticulum (ER) stress inhibitor, 4-phenylbutyrate, inhibited olanzapine-induced weight gain and ameliorated olanzapine-induced changes in hypothalamic GFAP, S100B, and TLR4 signaling. The expression of GFAP, S100B, and TLR4 correlated with food intake and weight gain. These findings suggested that olanzapine-induced increase in hypothalamic astrocytes and activation of TLR4 signaling were related to ER stress, and these effects may be related to olanzapine-induced obesity.

The implications of hypothalamic abnormalities for schizophrenia

Until a few years ago, the hypothalamus was believed to play only a marginal role in schizophrenia pathophysiology. However, recent findings show that this rather small brain region involved in many pathways found disrupted-in schizophrenia. Gross anatomic abnormalities (volume changes of the third ventricle, the hypothalamus, and its individual nuclei) as well as alterations at the cellular level (circumscribed loss of neurons) can be observed. Further, increased or decreased expression of hypothalamic peptides such as oxytocin, vasopressin, several factors involved in the regulation of appetite and satiety, endogenous opiates, products of schizophrenia susceptibility genes as well as of enzymes involved in neurotransmitter and neuropeptide metabolism have been reported in schizophrenia and/or animal models of the disease. Remarkably, although profound disturbances of the hypothalamus-pituitary-adrenal axis, hypothalamus-pituitary-thyroid axis, and the hypothalamus-pituitary-gonadal axis are typical signs of schizophrenia, there is currently no evidence for alterations in the expression of hypothalamic-releasing and inhibiting factors that control these hormonal axes. Finally, the implications of hypothalamus for disease-related disturbances of the sleep-wakefulness cycle and neuroimmune dysfunctions in schizophrenia are outlined.

Peripheral mechanisms of acute olanzapine induced metabolic dysfunction: A review of in vivo models and treatment approaches

Antipsychotic (AP) medications are associated with an increased risk for developing metabolic side effects including weight gain, dyslipidemia, hypertension, type 2 diabetes (T2D), and cardiovascular disease. Previous reviews have focused on the chronic metabolic side effects associated with AP use. However, an underappreciated aspect of APs are the rapid perturbations in glucose and lipid metabolism that occur with each dose of drug. The purpose of this narrative review is to summarize work examining the peripheral mechanisms of acute olanzapine-induced related metabolic disturbances. We also discuss recent studies that have attempted to elucidate treatment approaches to mitigate AP-induced impairments in fuel metabolism.

Biopsychosocial factors associated with disordered eating behaviors in schizophrenia

BACKGROUND

Recent hypotheses have suggested that schizophrenic patients are more likely to consume unhealthy foods, causing increased rates of mortality and morbidity associated with metabolic syndrome. This raises the need for more in-depth research on disordered eating behaviors (DEBs) in schizophrenic patients. This study, therefore, aimed to investigate biopsychosocial factors associated with DEBs in schizophrenia.

METHODS

In this cross-sectional study, a total of 308 participants (including 83 subjects in the active phase of schizophrenia, 71 subjects in the remission phase of schizophrenia, and 154 control subjects) were recruited through convenience sampling among patients who referred to the Baharan Psychiatric hospital in Zahedan, Iran. Patients were assessed through Eating Attitudes Test (EAT-26), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI-II), and Positive and Negative Syndrome Scale (PANSS). Data were analyzed using SPSS v25 software. Further, the statistical significance level was set at p < 0.05.

RESULTS

The prevalence of DEBs was 41.5% in schizophrenic patients (vs. 10.3% in the control group, p = 0.012). No significant difference was observed in the EAT-26 scores based on gender and phases of schizophrenia. According to multiple linear regression analysis, lack of psychosocial rehabilitation, use of atypical antipsychotics, early stages of psychosis, high level of anxiety and depression, expression of more active psychotic symptoms, tobacco smoking, and suffering from type 2 diabetes were all associated with increased development of DEBs among schizophrenic patients.

CONCLUSIONS

Since the occurrence of DEBs is independent of different phases of schizophrenia, the risk of DEBs is required to be evaluated during the entire course of schizophrenia especially at earlier stages of schizophrenia. Moreover, the use of psychosocial interventions, treatment of affective disorders (i.e., anxiety and depression), antipsychotic medication switching, treatment of tobacco smoking and type 2 diabetes may reduce the risk of DEBs among schizophrenic patients. However, further investigations are required to prove the actual roles of the above factors in developing DEBs among schizophrenic patients.

Carnosic acid prevented olanzapine-induced metabolic disorders through AMPK activation

Olanzapine, an atypical antipsychotic medication, has been associated with weight gain and metabolic toxicity, especially in long term usage. Carnosic acid (CA), a major constituent of rosemary extract, has been shown to improve metabolic abnormalities. In this experiment, the effect of CA on olanzapine-induced obesity and metabolic toxicity has been evaluated. Female Wistar rats were divided into six groups. (1) control; (2) olanzapine (5 mg/kg/day, IP); (3, 4 and 5) olanzapine (5 mg/kg/day, IP) plus CA (5, 10 and 20 mg/kg/day, gavage) and (6) CA (20 mg/kg/day, gavage). Bodyweight and food intake were measured during the study. After 14 days, mean systolic blood pressure (MSBP), glycemia, serum lipid profile, the serum concentration of leptin, insulin, AMPK, P-AMPK, and P-ACC liver protein levels were evaluated. The mean weight in the group received olanzapine increased by 4.8 g at the end of the study. The average food intake was increased by olanzapine. Olanzapine increased triglyceride, fasting blood glucose (FBG), and leptin levels. It increased MSBP and down-regulated P-AMPK/AMPK ratio and P-ACC protein levels. CA (three doses) decreased body weight gain and reduced average food intake at 10 and 20 mg/kg. CA especially at the highest dose decreased the changes in lipid profile, FBG, leptin level, and MSBP. P-AMPK/AMPK and P-ACC protein levels were increased by carnosic acid. In conclusion, the activation of AMPK by CA can be proposed as a key mechanism against olanzapine-induced metabolic toxicity where the activation of AMPK increases fat consumption and regulates glucose hemostasis in the liver.

Impaired hormonal regulation of appetite in schizophrenia: A narrative review dissecting intrinsic mechanisms and the effects of antipsychotics

Cardiometabolic diseases are the main contributor of reduced life expectancy in patients with schizophrenia. It is now widely accepted that antipsychotic treatment plays an important role in the development of obesity and its consequences. However, some intrinsic mechanisms need to be taken into consideration. One of these mechanisms might be related to impaired hormonal regulation of appetite in this group of patients. In this narrative review, we aimed to dissect impairments of appetite-regulating hormones attributable to intrinsic mechanisms and those related to medication effects. Early hormonal alterations that might be associated with intrinsic mechanisms include low levels of leptin and glucagon-like peptide-1 (GLP-1) together with elevated insulin levels in first-episode psychosis (FEP) patients. However, evidence regarding low GLP-1 levels in FEP patients is based on one large study. In turn, multiple-episode schizophrenia patients show elevated levels of insulin, leptin and orexin A together with decreased levels of adiponectin. In addition, patients receiving olanzapine may present with low ghrelin levels. Post mortem studies have also demonstrated reduced number of neuropeptide Y neurons in the prefrontal cortex of patients with schizophrenia. Treatment with certain second-generation antipsychotics may also point to these alterations. Although our understanding of hormonal regulation of appetite in schizophrenia has largely been improved, several limitations and directions for future studies need to be addressed. This is of particular importance since several novel pharmacological interventions for obesity and diabetes have already been developed and translation of these developments to the treatment of cardiometabolic comorbidities in schizophrenia patients is needed.

Olanzapine increases AMPK-NPY orexigenic signaling by disrupting H1R-GHSR1a interaction in the hypothalamic neurons of mice

Second generation antipsychotics, particularly olanzapine, induce severe obesity, which is associated with their antagonistic effect on the histamine H1 receptor (H1R). We have previously demonstrated that oral administration of olanzapine increases the concentration of neuropeptide Y (NPY) in the hypothalamus of rats, accompanied by hyperphagia and weight gain. However, it is unclear if the increased NPY after olanzapine administration is due to its direct effect on hypothalamic neurons and its H1R antagonistic property. In the present study, we showed that with an inverted U-shape dose-response curve, olanzapine increased NPY expression in the NPY-GFP hypothalamic neurons; however, this was not the case in the hypothalamic neurons of H1R knockout mice. Olanzapine inhibited the interaction of H1R and GHSR1a (ghrelin receptor) in the primary mouse hypothalamic neurons and NPY-GFP neurons examined by confocal fluorescence resonance energy transfer (FRET) technology. Furthermore, an H1R agonist, FMPH inhibited olanzapine activation of GHSR1a downstream signaling pAMPK and transcription factors of NPY (pFOXO1 and pCREB) in the hypothalamic NPY-GFP cell. However, an olanzapine analogue (E-Olan) with lower affinity to H1R presented negligible enhancement of pCREB within the nucleus of NPY neurons. These findings suggest that the H1R antagonist property of olanzapine inhibits the interaction of H1R and GHSR1a, activates GHSR1a downstream signaling pAMPK-FOXO1/pCREB and increases hypothalamic NPY: this could be one of the important molecular mechanisms of H1R antagonism of olanzapine-induced obesity in antipsychotic management of psychiatric disorders.

Molecular pathway analysis associates alterations in obesity-related genes and antipsychotic-induced weight gain

OBJECTIVE

Antipsychotics often induce excessive weight gain. We hypothesised that individuals with genetic variations related to known obesity-risk genes have an increased risk of excessive antipsychotic-induced weight gain (AIWG). This hypothesis was tested in a subset of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) trial data set.

METHODS

The CATIE trial compared effects and side effects of five different antipsychotics through an 18-month period. Based on the maximum weight gain recorded, excessive weight gain was defined as >7% weight gain. Cytoscape and GeneMANIA were instrumental in composing a molecular pathway from eight selected genes linked to obesity. Genetic information on a total of 495.172 single-nucleotide polymorphisms (SNPs) were available from 765 (556 males) individuals. Enrichment test was conducted through ReactomePA and Bioconductor. A permutation test was performed, testing the generated pathway against 105 permutated pathways (p ≤ 0.05). In addition, a standard genome-wide association study (GWAS) analysis was performed.

RESULT

GWAS analysis did not detect significant differences related to excessive weight gain. The pathway generated contained 28 genes. A total of 2067 SNPs were significantly expressed (p < 0.01) within this pathway when comparing excessive weight gainers to the rest of the sample. Affected genes including PPARG and PCSK1 were not previously related to treatment-induced weight gain.

CONCLUSIONS

The molecular pathway composed from high-risk obesity genes was shown to overlap with genetics of patients who gained >7% weight gain during the CATIE trial. This suggests that genes related to obesity compose a pathway of increased risk of excessive AIWG. Further independent analyses are warranted that may confirm or clarify the possible reasoning behind.

The dosage-dependent effects of cevimeline in preventing olanzapine-induced metabolic side-effects in female rats

Olanzapine has been used for the treatment of schizophrenia and other mental disorders. However, it is associated with serious weight gain and other metabolic side-effects. The antagonistic affinity of olanzapine to muscarinic M3 receptors has been evidenced as one of the main contributors for its weight gain and other metabolic side-effects. Therefore, this study investigated whether the co-treatment of cevimeline (a M3 receptor agonist) could prevent the metabolic side-effects associated with olanzapine medication. Female Sprague Dawley rats were treated orally with olanzapine (2 mg/kg, t.i.d.) and/or cevimeline at 3 dosages (3, 6, 9 mg/kg, t.i.d.), or vehicle for two weeks. Weight gain and food/water intake were measured throughout the drug treatment period. Intraperitoneal glucose tolerance tests and open field tests were conducted. Olanzapine-treated rats demonstrated significantly elevated body weight gain, food intake, feeding efficiency, total white fat mass, liver mass, and plasma triglyceride levels, which could be partly reversed by the co-treatment with cevimeline in a dosage-dependent manner. In general, the body weight gain can only be reversed by the co-treatment of 9 mg/kg cevimeline. The cevimeline co-treatment decreased plasma triglyceride and glucose levels compared with olanzapine only treatment. The results suggested a dosage-dependent effect of cevimeline in ameliorating olanzapine-induced weight gain and metabolic side-effects, which supports further clinical trials using cevimeline to control weight gain and metabolic side-effects caused by antipsychotic medications.

Berberine attenuated olanzapine-induced metabolic alterations in mice: Targeting transient receptor potential vanilloid type 1 and 3 channels

Transient receptor potential vanilloid type 1 (TRPV1) channels are emerging therapeutic targets for metabolic disorders. Berberine, which is a modulator of TRPV1, has proven antiobesity and antidiabetic potentials. The present study was aimed to investigate the protective effects of berberine in olanzapine-induced alterations in hypothalamic appetite control, inflammation and metabolic aberrations in mice targeting TRPV1 channels. Female BALB/c mice (18-23 g) were treated with olanzapine (6 mg/kg, p.o.) for six weeks to induce metabolic alterations, while berberine (100 and 200 mg/kg, p.o.) and metformin (100 mg/kg, p.o) were used as test and standard interventions respectively. Weekly assessment of feed-water intake, body temperature and body weight was done, while locomotion was measured at the end of week 1 and 6. Serum glucose and lipid profile were assessed by biochemical methods, while other serum biomarkers were assessed by ELISA. qPCR was used to quantify the mRNA expression in the hypothalamus. Olanzapine treatment significantly increased the feed intake, weight gain, adiposity index, while reduced body temperature and locomotor activity which were reversed by berberine treatment. Berberine treatment reduced serum ghrelin and leptin levels as well decrease in hypothalamic mRNA expression of orexigenic neuropeptides, inflammatory markers and ghrelin receptor in olanzapine-treated mice. Olanzapine treatment increased expression of TRPV1/TRPV3 in the hypothalamus which was significantly decreased by berberine treatment. Our results suggest that berberine, by TRPV1/TRPV3 modulation, attenuated the olanzapine-induced metabolic alterations in mice. Hence berberine supplementation in psychiatric patients could be a preventive approach to reduce the metabolic adverse effects of antipsychotics.

Food craving and consumption evolution in patients starting treatment with clozapine

BACKGROUND

Antipsychotic-induced weight gain has been especially related to clozapine and olanzapine. Underlying mechanisms in relation to food preferences with an increased food craving and consumption of specific nutrients have not been extensively studied in patients with serious mental illness (SMI). We aim to describe specific food preferences (craving) and subsequent food consumption in SMI patients starting clozapine, as well as their possible relation to weight and body mass index (BMI).

METHODS

An observational prospective follow-up study (18 weeks) was conducted in a cohort of 34 SMI patients who started clozapine due to resistant-psychotic symptoms. Anthropometric measures, Food Craving Inventory (FCI), and a food consumption frequency questionnaire were evaluated at baseline, weeks 8 and 18 of treatment. Statistical analysis included generalized estimating equations models with adjustment for potential confounding factors.

RESULTS

No longitudinal changes over time were found across the different food craving scores after 18 weeks of treatment. However, adjusted models according to BMI status showed that the normal weight (NW) group presented an increased score for the "complex carbohydrates/proteins" food cravings (- 0.67; 95% CI [- 1.15, - 0.19]; P = 0.010), while baseline scores for "fast-food fats" cravings were significantly higher in the overweight/obese (OWO) group in comparison with NW patients (NW, 2.05; 95% CI [1.60, 2.49]; OWO, 2.81, 95% CI [2.37, 3.25]; P = 0.016). When considering if food craving could predict weight gain, only increments in "fast-food fats" cravings were associated (β = - 5.35 ± 1.67; 95% CI [- 8.64, - 2.06]; P = 0.001).

CONCLUSIONS

No longitudinal differences were found for any of the food craving scores evaluated; however, in the NW group, food craving for "complex carbohydrates/proteins" changed. Thus, changes in "fast-food fats" cravings predicted weight increase in this sample. Interventions targeting food preferences may help to mitigate weight gain in patients starting treatment with clozapine.

Second-Generation Antipsychotics and Dysregulation of Glucose Metabolism: Beyond Weight Gain

Second-generation antipsychotics (SGAs) are the cornerstone of treatment for schizophrenia because of their high clinical efficacy. However, SGA treatment is associated with severe metabolic alterations and body weight gain, which can increase the risk of type 2 diabetes and cardiovascular disease, and greatly accelerate mortality. Several underlying mechanisms have been proposed for antipsychotic-induced weight gain (AIWG), but some studies suggest that metabolic changes in insulin-sensitive tissues can be triggered before the onset of AIWG. In this review, we give an outlook on current research about the metabolic disturbances provoked by SGAs, with a particular focus on whole-body glucose homeostasis disturbances induced independently of AIWG, lipid dysregulation or adipose tissue disturbances. Specifically, we discuss the mechanistic insights gleamed from cellular and preclinical animal studies that have reported on the impact of SGAs on insulin signaling, endogenous glucose production, glucose uptake and insulin secretion in the liver, skeletal muscle and the endocrine pancreas. Finally, we discuss some of the genetic and epigenetic changes that might explain the different susceptibilities of SGA-treated patients to the metabolic side-effects of antipsychotics.

Ketogenic diet and olanzapine treatment alone and in combination reduce a pharmacologically-induced prepulse inhibition deficit in female mice

We used the acute NMDA receptor hypoactivity model of schizophrenia in mice to compare the efficacy of a long-term ketogenic diet and a commonly used antipsychotic, olanzapine, and to explore the interaction between these treatments. We found that a ketogenic diet in female mice was as effective as olanzapine to diminish MK-801-induced disruption of prepulse inhibition (PPI). Furthermore, combination of the diet with olanzapine treatment resulted in a similar effect compared to either treatment alone. These results suggest that ketogenic diet can be used effectively together with antipsychotics drugs over an extended period.

Impact of histamine receptors H1 and H3 polymorphisms on antipsychotic-induced weight gain

OBJECTIVES

A positive correlation between antipsychotic-induced weight gain (AIWG) and the antagonist effect of antipsychotic drugs at the histamine H1 receptor (HRH1) as well as the agonist effect at the histamine H3 receptor (HRH3) in the brain has been consistently demonstrated. We investigated the potential impact of single-nucleotide polymorphisms (SNPs) in HRH1 and HRH3 genes on AIWG.

METHODS

We analysed 40 tagSNPs in HRH1 (n = 34) and HRH3 (n = 6) in schizophrenia/schizoaffective disorder patients (n = 193) primarily treated with clozapine or olanzapine for up to 14 weeks. Linear regression was used to evaluate the association between SNPs and AIWG, with baseline weight and treatment duration as covariates.

RESULTS

In HRH1, a nominal association of rs7639145 with AIWG was observed in patients of European ancestry treated with either clozapine or olanzapine (P= 0.043; β = 1.658; n = 77). We observed nominal association for two HRH1 SNPs rs346074 (P = 0.002; β = -5.024) and rs13064530 (P= 0.004; β = -5.158) in patients of African ancestry treated with either clozapine or olanzapine (n = 37). However, the above associations are not significant after correcting for multiple testing. In HRH3, we did not observe association in either ancestry.

CONCLUSIONS

The current study suggests that SNPs in HRH1 and HRH3 may not have a major role in AIWG.

Preclinical and Clinical Sex Differences in Antipsychotic-Induced Metabolic Disturbances: A Narrative Review of Adiposity and Glucose Metabolism

Antipsychotic (AP) medications are associated with an increased risk of developing metabolic side effects including weight gain, type 2 diabetes (T2D), dyslipidemia, and hypertension. In the majority of clinical studies, females on APs are noted to gain more weight, and are more likely to be diagnosed with metabolic syndrome when compared to males. However, the data is less clear when comparing sex disparities associated with other specific AP-induced metabolic risk factors. Accumulating evidence has demonstrated a role for AP-induced adipose tissue accumulation as well as whole body glucose dysregulation in male models that is independent of changes in body weight. The purpose of this narrative review is to explore the susceptibility of males and females to changes in adiposity and glucose metabolism across clinical and preclinical models of AP treatment. It is important that future research examining AP-induced metabolic side effects analyzes outcomes by sex to help clarify risk and identify the mechanisms of adverse event development to improve safe prescribing of medications.

Brain insulin action: Implications for the treatment of schizophrenia

Insulin action in the central nervous system is a major regulator of energy balance and cognitive processes. The development of central insulin resistance is associated with alterations in dopaminergic reward systems and homeostatic signals affecting food intake, glucose metabolism, body weight and cognitive performance. Emerging evidence has highlighted a role for antipsychotics (APs) to modulate central insulin-mediated pathways. Although APs remain the cornerstone treatment for schizophrenia they are associated with severe metabolic complications and fail to address premorbid cognitive deficits, which characterize the disorder of schizophrenia. In this review, we first explore how the hypothesized association between schizophrenia and CNS insulin dysregulation aligns with the use of APs. We then investigate the proposed relationship between CNS insulin action and AP-mediated effects on metabolic homeostasis, and different domains of psychopathology, including cognition. We briefly discuss a potential role of CNS insulin signaling to explain the hypothesized, but somewhat controversial association between therapeutic efficacy and metabolic side effects of APs. Finally, we propose how this knowledge might inform novel treatment strategies to target difficult to treat domains of schizophrenia. This article is part of the issue entitled 'Special Issue on Antipsychotics'.

One-Year Treatment with Olanzapine Depot in Female Rats: Metabolic Effects

BACKGROUND

Antipsychotic drugs can negatively affect the metabolic status of patients, with olanzapine as one of the most potent drugs. While patients are often medicated for long time periods, experiments in rats typically run for 1 to 12 weeks, showing olanzapine-related weight gain and increased plasma lipid levels, with transcriptional upregulation of lipogenic genes in liver and adipose tissue. It remains unknown whether metabolic status will deteriorate with time.

METHODS

To examine long-term metabolic effects, we administered intramuscular long-acting injections of olanzapine (100 mg/kg BW) or control substance to female rats for up to 13 months.

RESULTS

Exposure to olanzapine long-acting injections led to rapid weight gain, which was sustained throughout the experiment. At 1, 6, and 13 months, plasma lipid levels were measured in separate cohorts of rats, displaying no increase. Hepatic transcription of lipid-related genes was transiently upregulated at 1 month. Glucose and insulin tolerance tests indicated insulin resistance in olanzapine-treated rats after 12 months.

CONCLUSION

Our data show that the continuous increase in body weight in response to long-term olanzapine exposure was accompanied by surprisingly few concomitant changes in plasma lipids and lipogenic gene expression, suggesting that adaptive mechanisms are involved to reduce long-term metabolic adverse effects of this antipsychotic agent in rats.

A phenotypic Caenorhabditis elegans screen identifies a selective suppressor of antipsychotic-induced hyperphagia

Antipsychotic (AP) drugs are used to treat psychiatric disorders but are associated with significant weight gain and metabolic disease. Increased food intake (hyperphagia) appears to be a driving force by which APs induce weight gain but the mechanisms are poorly understood. Here we report that administration of APs to C. elegans induces hyperphagia by a mechanism that is genetically distinct from basal food intake. We exploit this finding to screen for adjuvant drugs that suppress AP-induced hyperphagia in C. elegans and mice. In mice AP-induced hyperphagia is associated with a unique hypothalamic gene expression signature that is abrogated by adjuvant drug treatment. Genetic analysis of this signature using C. elegans identifies two transcription factors, nhr-25/Nr5a2 and nfyb-1/NFYB to be required for AP-induced hyperphagia. Our study reveals that AP-induced hyperphagia can be selectively suppressed without affecting basal food intake allowing for novel drug discovery strategies to combat AP-induced metabolic side effects.

Disordered eating behaviors as a potential obesogenic factor in schizophrenia

Whilst people with schizophrenia have high levels of obesity and metabolic disease, our understanding of their eating behaviors is still limited. Our aim was to evaluate the relationships between eating behavior and clinical data in schizophrenia. A cross-sectional study including 66 schizophrenia outpatients compared to 81 healthy controls was undertaken. Eating behavior was assessed using the shortened 21-item version of the Three-Factor Eating Questionnaire (TFEQ-R21). The patients had a mean of 44 ± 11 years; a mean BMI of 30.3 ± 8 kg/m² (vs. 24 ± 3.3 kg/m² for controls) and a mean duration of illness of 7.2 ± 6 years. All mean TFEQ scores were significantly higher in patients (indicating poorer eating behaviors) compared to controls after adjustment for age and sex, BMI and smoking status. Among patients, mean TFEQ scores were not significantly different between men and women samples. The "cognitive restraint" factor was significantly higher in schizophrenia patients with a BMI < 25 than in the group of overweight patients with a BMI > 25. Our findings suggest that disordered eating behaviors affect schizophrenia patients regardless of gender or duration of disease compared to controls. More research is needed to help clarify the relationships between eating behaviors and weight-related outcomes in schizophrenia.

A role of neuropeptide CART in hyperphagia and weight gain induced by olanzapine treatment in rats

Although olanzapine is highly efficacious and most widely used second generation antipsychotic drug, the success of treatment has been hampered by its propensity to induce weight gain. While the underlying neuronal mechanisms are unclear, their elucidation may help to target alternative pathways regulating energy balance. The present study was undertaken to define the role of cocaine- and amphetamine-regulated transcript (CART), a well-known anorexic peptide, in olanzapine-induced hyperphagia and body weight gain in female rats. Olanzapine was administered daily by intraperitoneal route, alone or in combination with CART (intracerebroventricular) for a period of two weeks. Immediately after drug administrations, preweighed food was offered to the animals at the commencement of the dark phase. The food intake and body weight were measured daily just prior to next injection. Furthermore, the brains of olanzapine-treated rats were processed for the immunohistochemical analysis of CART-containing elements in the hypothalamus. Treatment with olanzapine (0.5 mg/kg) for the duration of 14 days produced a significant increase in food intake and body weight as compared to control. However, concomitant administration of CART (0.5 µg) attenuated the olanzapine-induced hyperphagia and weight gain. Olanzapine administration resulted in a significant reduction in CART immunoreactivity in the hypothalamic arcuate, paraventricular, dorsomedial and ventromedial nuclei. We suggest that decreased CART contents in the hypothalamus may be causally linked with the hyperphagia and weight gain induced by olanzapine.

Serum agouti-related protein (AgRP) levels in bipolar disorder: Could AgRP be a state marker for mania?

Orexigenic and anorexigenic peptides, especially agouti-related protein (AgRP) and leptin, play important roles in the regulation of energy homeostasis in bipolar disorder. AgRP regulates energy metabolism by increasing appetite and decreasing energy expenditure. The resting energy expenditures of patients with manic bipolar disorder are higher than those of controls. Due to the effects of AgRP on energy expenditure and the increased physical activity of manic patients, we hypothesised that serum AgRP levels may be lower in manic patients than in euthymic patients and controls. There was a total of 112 participants, including 47 patients in the manic group, 35 patients in the euthymic group and 30 healthy controls. For this study, serum AgRP, leptin, cholesterol, and cortisol levels were measured and compared between the groups. The serum AgRP, leptin, and cholesterol levels were significantly different between the groups. The serum AgRP levels of manic group were significantly lower than those of euthymic and control groups. The lower serum AgRP levels of manic patients could be indicators of impaired energy homeostasis during manic episodes. Since the serum AgRP levels of manic patients are lower than those of euthymic patients and controls, AgRP could be a state marker for manic episodes.

Metabolic Syndrome and Antipsychotics: The Role of Mitochondrial Fission/Fusion Imbalance

Second-generation antipsychotics (SGAs) are known to increase cardiovascular risk through several physiological mechanisms, including insulin resistance, hepatic steatosis, hyperphagia, and accelerated weight gain. There are limited prophylactic interventions to prevent these side effects of SGAs, in part because the molecular mechanisms underlying SGAs toxicity are not yet completely elucidated. In this perspective article, we introduce an innovative approach to study the metabolic side effects of antipsychotics through the alterations of the mitochondrial dynamics, which leads to an imbalance in mitochondrial fusion/fission ratio and to an inefficient mitochondrial phenotype of muscle cells. We believe that this approach may offer a valuable path to explain SGAs-induced alterations in metabolic homeostasis.

Analyzing AMPK Function in the Hypothalamus

Hypothalamic AMPK plays a key role in the control of energy homeostasis by regulating energy intake and energy expenditure, particularly modulating brown adipose tissue (BAT) thermogenesis. The function of AMPK can be assayed by analyzing its phosphorylated protein levels in tissues, since AMPK is activated when it is phosphorylated at Thr-172. Here, we describe a method to obtain hypothalamic (nuclei-specific) protein extracts and the suitable conditions to assay AMPK phosphorylation by Western blotting.

Molecular Mechanisms of Antipsychotic Drug-Induced Diabetes

Antipsychotic drugs (APDs) are widely prescribed to control various mental disorders. As mental disorders are chronic diseases, these drugs are often used over a life-time. However, APDs can cause serious glucometabolic side-effects including type 2 diabetes and hyperglycaemic emergency, leading to medication non-compliance. At present, there is no effective approach to overcome these side-effects. Understanding the mechanisms for APD-induced diabetes should be helpful in prevention and treatment of these side-effects of APDs and thus improve the clinical outcomes of APDs. In this review, the potential mechanisms for APD-induced diabetes are summarized so that novel approaches can be considered to relieve APD-induced diabetes. APD-induced diabetes could be mediated by multiple mechanisms: (1) APDs can inhibit the insulin signaling pathway in the target cells such as muscle cells, hepatocytes and adipocytes to cause insulin resistance; (2) APD-induced obesity can result in high levels of free fatty acids (FFA) and inflammation, which can also cause insulin resistance. (3) APDs can cause direct damage to β-cells, leading to dysfunction and apoptosis of β-cells. A recent theory considers that both β-cell damage and insulin resistance are necessary factors for the development of diabetes. In high-fat diet-induced diabetes, the compensatory ability of β-cells is gradually damaged, while APDs cause direct β-cell damage, accounting for the severe form of APD-induced diabetes. Based on these mechanisms, effective prevention of APD-induced diabetes may need an integrated approach to combat various effects of APDs on multiple pathways.

Time-dependent effects of olanzapine treatment on the expression of histidine decarboxylase, H1 and H3 receptor in the rat brain: The roles in olanzapine-induced obesity

Antipsychotic treatment, particularly olanzapine and clozapine, induces severe obesity. The Histamine H1 receptor is considered to be an important contributor to olanzapine-induced obesity, however how olanzapine modulates the histaminergic system is not sufficiently understood. This study examined the effect of olanzapine on key molecules of the histaminergic system, including histidine decarboxylase (HDC), H1 receptor (H1R) and H3 receptor (H3R), in the brain at different stages of olanzapine-induced obesity. During short-term treatment (8-day), olanzapine increased hypothalamic HDC mRNA expression and H1R binding in the arcuate nucleus (Arc) and ventromedial hypothalamus (VMH), without changing H3R binding density. HDC mRNA and Arc H1R binding were positively correlated with increased food intake, feeding efficiency and weight gain. When the treatment was extended to 16 and 36 days, H1R binding was increased not only in the hypothalamic Arc and VMH but also in the brainstem dorsal vagal complex (DVC). The H1R bindings in the Arc, VMH and DVC were positively correlated with weight gain induced by olanzapine treatment. However, the expression of HDC and H3R mRNA was not increased. These results suggest that olanzapine time-dependently modulates histamine neurotransmission, which suggested the different neuronal mechanisms underlying different stages of weight gain development. Treatment targeting the H1R may be effective for both short- and long-term olanzapine-induced weight gain.