Food intake and reward mechanisms in patients with schizophrenia: implications for metabolic disturbances and treatment with second-generation antipsychotic agents

Assessment of the relationship between food addiction and nutritional status in schizophrenic patients

OBJECTIVE

Obesity is one of today's most important public health problems. It is suggested that overeating and substance addiction show similarities, and addiction to food may be an important factor in the obesity epidemic. This study aimed to determine the prevalence of food addiction among schizophrenic patients and to examine the relationship between food addiction and anthropometric measurements and dietary nutrient intake.

METHODS

Study participants included a total of 104 schizophrenic outpatients, 62 females and 42 males. Food addiction was assessed by using the Yale Food Addiction Scale, and the anthropometric measurements of participants and their three-day food consumption were recorded.

RESULTS

This study found that more than half of the schizophrenic patients (60.6%) had food addiction, and that female schizophrenic patients had a higher prevalence (62.9%) of food addiction than male patients (57.1%). More than one-third of the schizophrenic patients with food addiction (41.3%) were found to be obese and their BMI, body weight, waist circumference, and body-fat ratio were higher than those of schizophrenic patients who did not have food addiction (P > 0.05). Moreover, the schizophrenic patients with food addiction were found to take significantly more energy, carbohydrate, and fat in their diet (P < 0.05).

CONCLUSION

It was observed that the development of food addiction in schizophrenic patients increased the risk of obesity and cardiovascular diseases, which were found to be at higher levels in these patients. Educational programs should be planned for these patients to acquire health dietary habits and to increase their physical activity levels, and an additional psychosocial support should be provided for patients with food addiction.

Investigating the link between drug-naive first episode psychoses (FEPs), weight gain abnormalities and brain structural damages: Relevance and implications for therapy

Evidence suggests that obesity and overweight may be associated with severe brain structural abnormalities and poor cognitive and functional outcomes in the general population. Despite these observations and the high prevalence of weight gain abnormalities in patients with psychosis spectrum disorders (PSDs), no studies have investigated the impact that these metabolic disturbances may have on brain structures and development in the earliest stages of PSDs. In the present review we shed light on the association between weight gain and brain structural abnormalities that may affect the course of illness in drug-naïve FEPs. Given the lack of studies directly investigating this issue, we firstly identified and critically evaluated the literature assessing weight gain abnormalities and gray or white matter (GM, WM) volumes (either globally or in specific regions of interest) in otherwise healthy obese/overweight adolescents and young adults. We then compared the results of this systematic review with those of two recent meta-analysis investigating GM and WM abnormalities in drug-naïve FEPs. Weight gain in otherwise healthy subjects was consistently associated with frontal and temporal GM atrophy and with reduced integrity of WM in the corpus callosum. Of relevance, all these brain regions are affected in drug-naïve FEPs, and their integrity is associated with clinical, cognitive and functional outcomes. The underlying mechanisms that may explain the association between weight gain, adiposity, and brain damage in both healthy subjects and drug-naïve FEPs are widely discussed. On the basis of this knowledge, we tried: a) to deduce an integrative model for the development of obesity in psychosis spectrum disorders; b) to identify the key vulnerability factors underlying the association between weight gain and psychosis; c) to provide information on new potential targets of intervention.

Oral glucose tolerance test performance in olanzapine-treated schizophrenia-spectrum patients is predicted by BMI and triglycerides but not olanzapine dose or duration

OBJECTIVE

Olanzapine, an atypical antipsychotic, is associated with glucoregulatory abnormalities, but the nature of this link is not fully elucidated. This is the first olanzapine oral glucose tolerance test (oGTT) study to consider treatment dose and duration, and to compare complementary indices respectively assessing insulin sensitivity (Matsuda index) and resistance (homeostasis model assessment).

METHODS

Body mass index (BMI), body composition, plasma lipids, and oGTT were measured in olanzapine-treated nondiabetic patients with DSM-IV-TR diagnosis of schizophrenia or schizoaffective disorder (n = 35).

RESULTS

While only one previously undiagnosed participant met diabetes criteria based on fasting plasma glucose alone (≥126 mg/dL), seven were diagnosed with oGTT (2-hr plasma glucose ≥200 mg/dL). Multiple regression analyses revealed that the Matsuda index correlated with BMI (p < 0.0001) and plasma triglycerides (p = 0.01), but not with age, olanzapine dose, olanzapine treatment duration, or plasma cholesterol. Homeostasis model assessment and fasting plasma glucose correlated with triglycerides only (p < 0.0001 for both).

CONCLUSIONS

Our data suggest that BMI and triglycerides may be implicated in olanzapine-related glucoregulatory abnormalities. The lack of correlation between glucoregulatory abnormalities and olanzapine dose or treatment duration suggests preexisting metabolic disturbances and/or disturbances arising early in the course of treatment. Clinicians prescribing antipsychotics should consider oGTT, especially in patients with obesity and/or hypertriglyceridemia.

Hypervulnerability of the adolescent prefrontal cortex to nutritional stress via reelin deficiency

Overconsumption of high-fat diets (HFDs) can critically affect synaptic and cognitive functions within telencephalic structures such as the medial prefrontal cortex (mPFC). The underlying mechanisms, however, remain largely unknown. Here we show that adolescence is a sensitive period for the emergence of prefrontal cognitive deficits in response to HFD. We establish that the synaptic modulator reelin (RELN) is a critical mediator of this vulnerability because (1) periadolescent HFD (pHFD) selectively downregulates prefrontal RELN⁺ cells and (2) augmenting mPFC RELN levels using transgenesis or prefrontal pharmacology prevents the pHFD-induced prefrontal cognitive deficits. We further identify N-methyl-d-aspartate-dependent long-term depression (NMDA-LTD) at prefrontal excitatory synapses as a synaptic signature of this association because pHFD abolishes NMDA-LTD, a function that is restored by RELN overexpression. We believe this study provides the first mechanistic insight into the vulnerability of the adolescent mPFC towards nutritional stress, such as HFDs. Our findings have primary relevance to obese individuals who are at an increased risk of developing neurological cognitive comorbidities, and may extend to multiple neuropsychiatric and neurological disorders in which RELN deficiency is a common feature.

Serum fatty acid patterns in patients with schizophrenia: a targeted metabonomics study

Previous studies have indicated that schizophrenia is linked to abnormal lipid metabolism. Free fatty acids (FFAs) in peripheral blood can reflect the status of lipid metabolism in human body. The purpose of this study was to scan the FFA pattern and elucidate the characteristics of lipid metabolic abnormality in schizophrenia patients. One hundred and ten patients with schizophrenia (SCZs) and 109 healthy controls (HCs) were included in the study and divided into a discovery set and a validation set. Forty-seven serum FFAs were detected by UPLC-QTOF-MS and 39 of them were absolutely quantified by establishing standard curves. Monounsaturated fatty acids (MUFAs) and ω-6 polyunsaturated fatty acids (ω-6 PUFAs) were significantly increased in SCZs compared with HCs. Desaturation from saturated fatty acids to MUFAs and β-oxidation were enhanced, as estimated by the ratios of products to precursors. These results suggest that lipolysis and β-oxidation are upregulated in SCZ, presumably resulting from insufficient brain energy supply.

Adherence to NICE guidance on lifestyle advice for people with schizophrenia: a survey

Aims and method The STEPWISE trial (STructured lifestyle Education for People WIth SchizophrEnia, schizoaffective disorder and first episode psychosis) is currently evaluating a lifestyle education programme in addition to usual care. However, it is difficult to define what constitutes 'usual care'. We aimed to define 'usual care' for lifestyle management in people with schizophrenia, schizoaffective disorder and first-episode psychosis in STEPWISE study sites. Ten National Health Service (NHS) mental health trusts participated in a bespoke survey based on the National Institute for Health and Care Excellence (NICE) guidance. Results Eight trusts reported offering lifestyle education programmes and nine offered smoking cessation support. Reported recording of biomedical measures varied. Clinical implications Although recommended by NICE, lifestyle education programmes are not consistently offered across UK NHS mental health trusts. This highlights missed opportunities to improve the physical health of people with psychotic illness. Our survey benchmarks 'usual care' for the STEPWISE study, against which changes can be measured. Furthermore, future studies will be able to identify whether any progress in clinical practice has been made towards achieving the NICE recommendations.

Modified Mediterranean Diet for Enrichment of Short Chain Fatty Acids: Potential Adjunctive Therapeutic to Target Immune and Metabolic Dysfunction in Schizophrenia?

Growing interest in gut and digestive processes and their potential link to brain and peripheral based inflammation or biobehavioral phenotypes has led to an increasing number of basic and translational scientific reports focused on the role of gut microbiota within the context of neuropsychiatric disorders. However, the effect of dietary modification on specific gut metabolites, in association with immune, metabolic, and psychopathological functioning in schizophrenia spectrum disorders has not been well characterized. The short chain fatty acids (SCFA) acetate, butyrate, and propionate, major metabolites derived from fermentation of dietary fibers by gut microbes, interact with multiple immune and metabolic pathways. The specific pathways that SCFA are thought to target, are dysregulated in cardiovascular disease, type II diabetes, and systemic inflammation. Most notably, these disorders are consistently linked to an attenuated lifespan in schizophrenia. Although, unhealthy dietary intake patterns and increased prevalence of immune and metabolic dysfunction has been observed in people with schizophrenia; dietary interventions have not been well utilized to target immune or metabolic illness. Prior schizophrenia patient trials primarily focused on the effects of gluten free diets. Findings from these studies indicate that a diet avoiding gluten benefits a limited subset of patients, individuals with celiac disease or non-celiac gluten sensitivity. Therefore, alternative dietary and nutritional modifications such as high-fiber, Mediterranean style, diets that enrich the production of SCFA, while being associated with a minimal likelihood of adverse events, may improve immune and cardiovascular outcomes linked to premature mortality in schizophrenia. With a growing literature demonstrating that SCFA can cross the blood brain barrier and target key inflammatory and metabolic pathways, this article highlights enriching dietary intake for SCFA as a potential adjunctive therapy for people with schizophrenia.

A novel inhibitor of endocannabinoid catabolic enzymes sheds light on behind the scene interplay between chronic pain, analgesic tolerance, and heroin dependence

From the Aristotelian ancient Greece, pain has been associated with appetites or emotions and is opposite to pleasure. Reward and addiction is also linked to pleasure and compulsive drug seeking reinstates pleasure. Alleviation of chronic pain can induce a euphoric phase similar to what is found in addiction. Both chronic pain and addiction are recognized as a disease of the central nervous system. They share many characteristics and brain regions/mechanisms. Evidence points to the usefulness of cannabinoids as a new class of agents to add to the pharmaceutical toolbox in the management of chronic pain. Wilkerson and colleagues, in this issue, examine SA-57, an inhibitor of two different endocannabinoid catabolic enzymes FAAH and MAGL, demonstrating its analgesic effectiveness and morphine-sparing properties in a chronic pain model, as well as its ability to reduce heroin seeking behavior in a self-administration paradigm in mice. This timely study emphasizes the need for development of more efficacious chronic pain therapeutics with minimized abuse potential and/or reinforcing properties. It also highlights the need for better understanding of the overlapping circuitry of chronic pain, reward, and addiction.

STEPWISE - STructured lifestyle Education for People WIth SchizophrEnia: a study protocol for a randomised controlled trial

Background

People with schizophrenia are two to three times more likely to be overweight than the general population. The UK National Institute of Health and Care Excellence (NICE) recommends an annual physical health review with signposting to, or provision of, a lifestyle programme to address weight concerns and obesity. The purpose of this randomised controlled trial is to assess whether a group-based structured education programme can help people with schizophrenia to lose weight.

Methods

Design: a randomised controlled trial of a group-based structured education programme.

Setting: 10 UK community mental health trusts.

Participants: 396 adults with schizophrenia, schizoaffective, or first-episode psychosis who are prescribed antipsychotic medication will be recruited. Participants will be overweight, obese or be concerned about their weight.

Intervention: participants will be randomised to either the intervention or treatment as usual (TAU). The intervention arm will receive TAU plus four 2.5-h weekly sessions of theory-based lifestyle structured group education, with maintenance contact every 2 weeks and ‘booster’ sessions every 3 months. All participants will receive standardised written information about healthy eating, physical activity, alcohol and smoking.

Outcomes: the primary outcome is weight (kg) change at 1 year post randomisation. Secondary outcomes, which will be assessed at 3 and 12 months, include: the proportion of participants who maintained or reduced their weight; waist circumference; body mass index; objectively measured physical activity (wrist accelerometer); self-reported diet; blood pressure; fasting plasma glucose, lipid profile and HbA_1c (baseline and 1 year only); health-related quality of life (EQ-5D-5L and RAND SF-36); (adapted) brief illness perception questionnaire; the Brief Psychiatric Rating Scale; the Client Service Receipt Inventory; medication use; smoking status; adverse events; depression symptoms (Patient Health Questionnaire-9); use of weight-loss programmes; and session feedback (intervention only). Outcome assessors will be blind to trial group allocation.

Qualitative interviews with a subsample of facilitators and invention-arm participants will provide data on intervention feasibility and acceptability. Assessment of intervention fidelity will also be performed.

Discussion

The STEPWISE trial will provide evidence for the clinical and cost-effectiveness of a tailored intervention, which, if successful, could be implemented rapidly in the NHS.

Trial registration

ISRCTN19447796, registered on 20 March 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1572-1) contains supplementary material, which is available to authorized users.

Prenatal Inflammation, Infections and Mental Disorders

BACKGROUND

The objective of this descriptive review is to summarize the current scientific evidence on the effect of prenatal exposure to maternal infection and immune response on the offspring's risk for mental disorders (schizophrenia spectrum disorders, autism spectrum disorders, attention-deficit hyperactivity disorder, anorexia nervosa, and mood disorders).

SAMPLING AND METHODS

Studies were searched from PubMed and Ovid MEDLINE (R) databases with the following keywords: 'prenatal exposure delayed effects' and 'infection', and 'inflammation' and 'mental disorders'. A comprehensive manual search, including a search from the reference list of included articles, was also performed.

RESULTS

Prenatal exposure to maternal influenza appears to increase the offspring's risk for schizophrenia spectrum disorders, although studies are not fully consistent. Prenatal exposure to maternal fever and elevated cytokine levels seems to be related to the elevated risk for autism spectrum disorders in the offspring. No replicated findings of an association between prenatal infectious exposure and other mental disorders exist.

CONCLUSIONS

Evidence for the effect of prenatal exposure to maternal infection on risk for mental disorders exists for several different infections, suggesting that common factors occurring in infections (e.g. elevated cytokine levels and fever), rather than the infectious agent itself, might be the underlying factor in increasing the risk for mental disorders. Additionally, it is likely that genetic liability to these disorders operates in conjunction with the exposure. Therefore, genetically sensitive study designs are needed in future studies.

Abnormal context-reward associations in an immune-mediated neurodevelopmental mouse model with relevance to schizophrenia

Impairments in central reward processing constitute an important aspect of the negative symptoms of schizophrenia. Despite its clinical relevance, the etiology of deficient reward processing in schizophrenia remains largely unknown. Here, we used an epidemiologically informed mouse model of schizophrenia to explore the effects of prenatal immune activation on reward-related functions. The model is based on maternal administration of the viral mimic PolyI:C and has been developed in relation to the epidemiological evidence demonstrating enhanced risk of schizophrenia and related disorders following prenatal maternal infection. We show that prenatal immune activation induces selective deficits in the expression (but not acquisition) of conditioned place preference for a natural reward (sucrose) without changing hedonic or neophobic responses to the reward. On the other hand, prenatal immune activation led to enhanced place preference for the psychostimulant drug cocaine, while it attenuated the locomotor reaction to the drug. The prenatal exposure did not alter negative reinforcement learning as assessed using a contextual fear conditioning paradigm. Our findings suggest that the nature of reward-related abnormalities following prenatal immune challenge depends on the specificity of the reward (natural reward vs drug of abuse) as well as on the valence domain (positive vs negative reinforcement learning). Moreover, our data indicate that reward abnormalities emerging in prenatally immune-challenged offspring may, at least in part, stem from an inability to retrieve previously established context-reward associations and to integrate such information for appropriate goal-directed behavior.

Metabolic syndrome among psychiatric inpatients with schizophrenia in Indonesia

Despite the fact that antipsychotic medication increases the risk of metabolic syndrome (MetS), the rate of MetS among psychiatric patients in Indonesia is rarely reported. This study aimed to investigate the prevalence of MetS among inpatients with schizophrenia in Indonesia. Eighty-six hospitalised psychiatric patients with schizophrenia were randomly recruited, and underwent physical examination including a blood test. MetS was assessed based on the International Diabetes Federation (IDF) criteria for South Asia. Among the sample, only eight patients (9.3%) met the IDF criteria for MetS. Women have a higher rate of MetS than men (23.8% vs 4.6%; p=0.02). Reduced high-density lipoprotein (HDL) cholesterol was the most frequent (81.4%) metabolic abnormality among them, followed by central obesity (29.1%), raised triglycerides (23.3%), raised fasting plasma glucose (12.8%), and raised blood pressure (10.5%). Among the various antipsychotics, no differences in MetS prevalence were observed in this population. The rate of MetS among the psychiatric inpatients in this study is lower compared both to the previously reported rate in the general population and to the findings among psychiatric patients with schizophrenia in developed countries. Several factors related to the reduced rate of MetS in this psychiatric inpatient population will be discussed.

The effect of naltrexone on body fat mass in olanzapine-treated schizophrenic or schizoaffective patients: a randomized double-blind placebo-controlled pilot study

Olanzapine (OLZ), a commonly prescribed second generation antipsychotic drug, is associated with obesity and metabolic syndrome and may contribute to increased cardiovascular morbidity and mortality. Opioidergic neurotransmission may be implicated in the development of these metabolic disturbances. The objective of this study was to assess the effects of opioid blockade on OLZ-treated patients' metabolic status. Patients with schizophrenia or schizoaffective disorder (n=30) on a stable dose of OLZ were randomized in a double-blind fashion to receive an opioid receptor antagonist, naltrexone (NTX), (n=14) or placebo (n=16). The primary outcome measure was the change in body mass index (BMI) at 12 weeks. Secondary measures included body fat and fat-free mass, along with homeostasis model assessment-estimated insulin resistance (HOMA-IR), plasma lipids and liver function tests (LFTs). There was no significant change in BMI between the treatment arms. However, in comparison to the OLZ + placebo combination, the OLZ + NTX group displayed a significant decrease in the fat and increase in fat-free mass along with a trend towards improvement in HOMA-IR values. There were no significant differences in plasma lipids and LFTs. These findings suggest that addition of NTX to OLZ may attenuate OLZ-induced body fat mass gain. A larger study of longer duration will be needed to confirm these results.

Unraveling the relationship between obesity, schizophrenia and cognition

INTRODUCTION

Previous studies investigating the relationship between obesity and cognition as well as gender differences in these relationships reported equivocal results. Here, we examined age, years of education, schizophrenia, and gender differences which might affect the relationship between obesity and cognition.

METHODS

1012 healthy controls and 707 participants with schizophrenia were recruited. Information on body mass index (BMI) was obtained and a neurocognitive battery was administered. Structural equation modeling (SEM) was performed to examine the relationship between BMI, schizophrenia, cognition and its covariates.

RESULTS

No significant direct effect of BMI on cognition was found when cognition was regressed on age, years of education, diagnosis of schizophrenia and BMI. Instead, two SEM models indicated that indirect effects between BMI and cognition exist. The indirect effect of BMI on cognition through schizophrenia was present in both genders, while the indirect effect of cognition on BMI through schizophrenia was only found in females. BMI affecting cognition through age, years of education and schizophrenia appears to be the most plausible model that explains the data. This indirect effect was larger in females and was masked by diagnosis of schizophrenia.

CONCLUSION

With increased rates of obesity in schizophrenia, it is important to highlight the potentially deleterious effect of obesity on cognition. BMI could be used as a candidate risk marker to identify people at higher risk of cognitive deficits, and as an intervention target for modifications of cognitive outcomes.

Allostatic load as a tool for monitoring physiological dysregulations and comorbidities in patients with severe mental illnesses

Severe mental illnesses like schizophrenia and bipolar disorder are disabling, chronic conditions that are often accompanied by medical comorbidities. In this theoretical article, we review the allostatic load model representing the "wear and tear" that chronic stress exacts on the brain and body. We propose an innovative way of monitoring physical and psychiatric comorbidities by integrating the allostatic load model into clinical practice. By interpreting peripheral biomarkers differently, medical professionals can calculate a simple, count-based, allostatic load index known to predict diverse stress-related pathologies. In addition to screening for comorbidities, allostatic load indices can be used to monitor the effects of pharmacological and psychosocial interventions. This framework can also be used to generate a dialogue between patient and practitioner to promote preventive and proactive approaches to health care.

The role of ghrelin signalling in second-generation antipsychotic-induced weight gain

Based on clinical and animal studies, this review suggests a tri-phasic effect of second-generation antipsychotics (SGAs) on circulating ghrelin levels: an initial increase exerted by the acute effect of SGAs; followed by a secondary decrease possibly due to the negative feedback from the SGA-induced body weight gain or hyperphagia; and a final re-increase to reach the new equilibrium. Moreover, the results can also vary depending on individual SGAs, other hormonal states, dietary choices, and other confounding factors including medical history, co-treatments, age, gender, and ghrelin measurement techniques. Interestingly, rats treated with olanzapine, an SGA with high weight gain liabilities, are associated with increased hypothalamic ghrelin receptor (GHS-R1a) levels. In addition, expressions of downstream ghrelin signalling parameters at the hypothalamus, including neuropeptide Y (NPY)/agouti-related peptide (AgRP) and proopiomelanocortin (POMC) are also altered under SGA treatments. Thus, understanding the role of ghrelin signalling in antipsychotic drug-induced weight gain should offer potential novel pharmacological targets for tackling the obesity side-effect of SGAs and its associated metabolic syndrome.

Pain and suicidality: insights from reward and addiction neuroscience

Suicidality is exceedingly prevalent in pain patients. Although the pathophysiology of this link remains unclear, it may be potentially related to the partial congruence of physical and emotional pain systems. The latter system's role in suicide is also conspicuous during setbacks and losses sustained in the context of social attachments. Here we propose a model based on the neural pathways mediating reward and anti-reward (i.e., allostatic adjustment to recurrent activation of the reward circuitry); both are relevant etiologic factors in pain, suicide and social attachments. A comprehensive literature search on neurobiology of pain and suicidality was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) physical and emotional pain, (2) emotional pain and social attachments, (3) pain- and suicide-related alterations of the reward and anti-reward circuits as compared to addiction, which is the premier probe for dysfunction of these circuits and (4) mechanistically informed treatments of co-occurring pain and suicidality. Pain-, stress- and analgesic drugs-induced opponent and proponent states of the mesolimbic dopaminergic pathways may render reward and anti-reward systems vulnerable to sensitization, cross-sensitization and aberrant learning of contents and contexts associated with suicidal acts and behaviors. These findings suggest that pain patients exhibit alterations in the brain circuits mediating reward (depressed function) and anti-reward (sensitized function) that may affect their proclivity for suicide and support pain and suicidality classification among other "reward deficiency syndromes" and a new proposal for "enhanced anti-reward syndromes". We suggest that interventions aimed at restoring the balance between the reward and anti-reward networks in patients with chronic pain may help decreasing their suicide risk.

Effects of antipsychotic medications on appetite, weight, and insulin resistance

Although clozapine, olanzapine, and other atypical antipsychotic drugs (APDs) have fewer extrapyramidal side effects, they have serious metabolic side effects such as substantial weight gain, intra-abdominal obesity, and type 2 diabetes mellitus. Given that most patients with mental disorders face chronic, even life-long, treatment with APDs, the risks of weight gain/obesity and other metabolic symptoms are major considerations for APD maintenance treatment. This review focuses on the effects of APDs on weight gain, appetite, insulin resistance, and glucose dysregulation, and the relevant underlying mechanisms that may be help to prevent and treat metabolic side effects caused by APD therapy.

Central nervous system biomarkers for antiobesity drug development

•

Neuroimaging, cognitive and behavioural biomarkers can aid antiobesity drug development.

•

These biomarkers can detect early signals of mechanistic efficacy and adverse effects.

•

In Phase II biomarkers can provide proof-of-concept to inform the decision to advance to Phase III.

•

Potential biomarker candidates that have been used with antiobesity drugs are discussed.

•

These candidate biomarkers need further exploration, standardisation and validation.

With antiobesity agents, weight loss can emerge from an array of metabolic, cognitive and behavioural changes that translate into weight change over time. In early drug development, characterising these changes can actually be more informative than simply measuring weight loss. Biomarkers for these mechanisms can be used to determine whether potential compounds are worth developing further by providing proof of mechanistic action and detecting early signs of neuropsychiatric adverse effects. In this review, we examine potential biomarkers for effects on metabolism and satiety, hedonics and motivation, and eating behaviour. We also review biomarkers for early detection of neuropsychiatric adverse effects.

Nucleus accumbens GABAergic inhibition generates intense eating and fear that resists environmental retuning and needs no local dopamine

Intense fearful behavior and/or intense appetitive eating behavior can be generated by localized amino acid inhibitions along a rostrocaudal anatomical gradient within medial shell of nucleus accumbens of the rat. This can be produced by microinjections in medial shell of either the γ-aminobutyric acid (GABA)A agonist muscimol (mimicking intrinsic GABAergic inputs) or the AMPA (α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) antagonist DNQX (6,7-dinitroquinoxaline-2,3-dione), disrupting corticolimbic glutamate inputs). At rostral sites in medial shell, each drug robustly stimulates appetitive eating and food intake, whereas at more caudal sites the same drugs instead produce increasingly fearful behaviors such as escape, distress vocalizations and defensive treading (an antipredator behavior rodents emit to snakes and scorpions). Previously we showed that intense motivated behaviors generated by glutamate blockade require local endogenous dopamine and can be modulated in valence by environmental ambience. Here we investigated whether GABAergic generation of intense appetitive and fearful motivations similarly depends on local dopamine signals, and whether the valence of motivations generated by GABAergic inhibition can also be retuned by changes in environmental ambience. We report that the answer to both questions is 'no'. Eating and fear generated by GABAergic inhibition of accumbens shell does not need endogenous dopamine. Also, the appetitive/fearful valence generated by GABAergic muscimol microinjections resists environmental retuning and is determined almost purely by rostrocaudal anatomical placement. These results suggest that nucleus accumbens GABAergic release of fear and eating are relatively independent of modulatory dopamine signals, and more anatomically pre-determined in valence balance than release of the same intense behaviors by glutamate disruptions.

Determination of olanzapine and N-desmethyl-olanzapine in plasma using a reversed-phase HPLC coupled with coulochemical detection: correlation of olanzapine or N-desmethyl-olanzapine concentration with metabolic parameters

BACKGROUND

Olanzapine (OLZ) is one of the most prescribed atypical antipsychotic drugs but its use is associated with unfavorable metabolic abnormalities. N-desmethyl-olanzapine (DMO), one of the OLZ metabolites by CYP1A2, has been reported to have a normalizing action on metabolic abnormalities, but this remains unclear. Our aim was to explore the correlation between the concentrations of OLZ or DMO with various metabolic parameters in schizophrenic patients.

METHODS

The chromatographic analysis was carried out with a solvent delivery system coupled to a Coulochem III coulometric detector to determine OLZ and DMO simultaneously in OLZ-treated patients. The correlation between the concentration of OLZ or DMO and the metabolic parameters was analyzed by the Spearman rank order correlation method (r s).

PRINCIPAL FINDINGS

The established analytical method met proper standards for accuracy and reliability and the lower limitation of quantification for each injection of DMO or OLZ was 0.02 ng. The method was successfully used for the analysis of samples from nonsmoking patients (n = 48) treated with OLZ in the dosage range of 5-20 mg per day. There was no correlation between OLZ concentrations and tested metabolic parameters. DMO concentrations were negatively correlated with glucose (r s = -0.45) and DMO concentrations normalized by doses were also negatively correlated with insulin levels (r s = -0.39); however, there was a marginally positive correlation between DMO and homocysteine levels (r s = +0.38).

CONCLUSIONS

The observed negative correlations between levels of DMO and glucose or insulin suggest a metabolic normalization role for DMO regardless of its positive correlation with a known cardiovascular risk factor, homocysteine. Additional studies of the mechanisms underlying DMO's metabolic effects are warranted.

Neurological soft signs in individuals with pathological gambling

Increased neurological soft signs (NSSs) have been found in a number of neuropsychiatric syndromes, including chemical addiction. The present study examined NSSs related to perceptual-motor and visuospatial processing in a behavioral addiction viz., pathological gambling (PG). As compared to mentally healthy individuals, pathological gamblers displayed significantly poorer ability to copy two- and three-dimensional figures, to recognize objects against a background noise, and to orient in space on a road-map test. Results indicated that PG is associated with subtle cerebral cortical abnormalities. Further prospective clinical research is needed to address the NSSs' origin and chronology (e.g., predate or follow the development of PG) as well as their response to therapeutic interventions and/or their ability to predict such a response.

CNR1 gene and risk of the metabolic syndrome in patients with schizophrenia

Metabolic disturbances are more prevalent in patients with schizophrenia (SCZ) than in the general population. The endocannabinoid system plays an important role in the regulation of dopamine transmission and several metabolic pathways, and the endocannabinoid receptor type 1 gene (CNR1) is considered a candidate gene for both SCZ and metabolic disorders. We examined whether genetic variation in CNR1 was associated with metabolic syndrome (MetS) in a naturalistic cohort of 407 patients with SCZ. The minor alleles of rs6928499, rs1535255, and rs2023239 were nominally associated with a lower risk of MetS [odds ratio (OR), 0.56; 95% confidence interval (CI), 0.37-0.84; P = 0.006; OR, 0.56; 95% CI, 0.37-0.84; P = 0.006; and OR, 0.44; 95% CI, 0.27-0.72; P = 0.001, respectively, adjusted for age, sex, duration of illness, clozapine or olanzapine treatment). These differences were mainly due to differences in high-density lipoprotein cholesterol and fasting glucose but not in body mass index or waist circumference. No significant association of the other polymorphisms (rs806377, rs1049353, rs6454674, and rs806379) with MetS was found. These results provide evidence that the prevalence of MetS is associated with the CNR1 gene in patients with SCZ during long-term treatment with antipsychotic treatment. Further studies are needed to uncover the exact molecular basis for this association, which could provide novel treatment targets for the MetS.

Priming of metabolic dysfunctions by prenatal immune activation in mice: relevance to schizophrenia

Schizophrenia is associated with increased risk for multiple metabolic abnormalities, including altered glucose homeostasis, type-2 diabetes, obesity, and cardiovascular disease. Some of the metabolic alterations can already exist in psychosis-prone subjects prior to the onset of chronic schizophrenic disease and pharmacotherapy, indicating that they may have a developmental origin. In the present study, we tested the hypothesis that metabolic alterations pertinent to schizophrenic disease can be primed by an environmental risk factor associated with the disorder, namely prenatal exposure to immune challenge. We used a well-established mouse model of prenatal immune challenge induced by maternal gestational treatment with poly(I:C) (="polyriboinosinic-polyribocytidilic acid"), an analog of double-stranded RNA that stimulates a cytokine-associated viral-like acute phase response. Metabolic effects were studied using high-resolution computed tomography and fully automated indirect calorimetry system, along with an oral glucose tolerance test and plasma cytokine and corticosterone measurements. We found that prenatal immune activation caused altered glycemic regulation and abnormal ingestive behavior in periadolescence and led to an adult onset of excess visceral and subcutaneous fat deposition. These effects were accompanied by age-dependent changes in peripheral secretion of proinflammatory (interleukin [IL]-6 and tumor necrosis factor [TNF]-α) and T cell-related (IL-2 and interferon [IFN]-γ) cytokines and by increased release of the stress hormone corticosterone in periadolescence. Our findings show that schizophrenia-relevant metabolic and physiological abnormalities can be primed by prenatal viral-like immune activation, but at the same time, our study emphasizes that this environmental insult is unlikely to precipitate the full spectrum of metabolic and immunological changes pertinent to chronic schizophrenic disease.

Pharmacotherapies for Overeating and Obesity

Obesity has become pandemic, and the annual cost in related illnesses and loss of productivity is already over $100 billion and rising. Research has shown that obesity can and does cause changes in behavior and in the brain itself that are very similar to changes caused by drugs of abuse. While food addiction is not the causal agent of all obesity, it is clear that many people no longer eat to survive, but instead survive to eat. This review considers the importance of the brain's reward system in food intake. The review also examines research developments and current treatments for obesity, including diet and exercise, psychotherapy, surgical interventions, and pharmacotherapies. Finally we discuss alterations in American society that are necessary for change to occur, and the diffculties therein.

Olanzapine and risperidone effects on appetite and ghrelin in chronic schizophrenic patients

Olanzapine and other second generation antipsychotics have been associated with weight gain, which may be related to changes in appetite and food intake. However, it is unclear whether changes in appetite in response to treatment with second generation antipsychotics are persistent in patients treated chronically with these medications and the extent to which changes in appetite are related to any continuing weight gain associated with long-term treatment with these drugs. In a randomized 5-month study of the effects of olanzapine and risperidone on metabolic changes in chronic schizophrenic patients, we assessed appetite changes using two scales and correlated appetite changes with weight gain and metabolic changes. There is evidence that the hormone ghrelin is related to appetite stimulation and falls during satiation after meals, and therefore, may be a physiological concomitant indicating appetite changes. We therefore, also measured ghrelin before and after a fatty meal at baseline and after 2 months of drug treatment. Neither olanzapine nor risperidone increased appetite during the 5 months of study drug treatment, and there was a trend for a decrease in appetite over time. Weight only increased slightly during treatment and changes in appetite scores were not correlated with changes in weight or changes in glucose or lipids. Fasting ghrelin did not increase in olanzapine- or risperidone-treated patients, and there were no significant changes in ghrelin responses to a fatty meal between baseline and 2 months of drug treatment, and no differences in response in olanzapine- vs. risperidone-treated patients. Our findings suggest that in chronic schizophrenic patients treated with multiple antipsychotics in the past, olanzapine or risperidone do not induce increases in appetite and appetite changes are not related to any further small drug-induced weight gain in these chronically treated patients. However, it is possible that different relationships may exist between appetite and weight changes induced by the medications in drug naive patients newly started on olanzapine or risperidone.

Effects of naltrexone on food intake and body weight gain in olanzapine-treated rats

Blockade of opioidergic neurotransmission contributes to reduction in body weight. However, how such blockade affects body weight gain (BWG) attributed to second generation antipsychotic agents (SGAs) has not yet been established. Here we examined the effects of an opioid receptor antagonist, naltrexone (NTX), on food intake and BWG associated with an SGA, olanzapine (OL). Four groups of Wistar Han IGS rats were treated for 28 days with either OL (2 mg/kg twice daily, intraperitoneal (IP)), a combination of OL (2 mg/kg twice daily, IP) + extended-release NTX (50 mg/kg, one-time, intramuscular (IM)), extended-release NTX (50 mg/kg, one-time, IM) or vehicle and their food intake and body weight were measured daily for the first nine days and every other day thereafter. Food intake and BWG that were increased by OL were decreased by the added NTX while NTX alone had no significant effects on food intake or on BWG. Plasma leptin concentrations were significantly elevated in the three groups receiving pharmacological agents, but did not differ among each other, suggesting that changes in leptin secretion and/or clearance alone would not explain the food intake and the body weight findings. Our results extend prior reports on anorexigenic effects of opioid antagonists by demonstrating that such effects may generalize to food intake increases and BWG arising in the context of OL pharmacotherapy.

Depot naltrexone decreases rewarding properties of sugar in patients with opioid dependence

BACKGROUND

Opioid neurotransmission mediates hedonic value of sweet tastants; their intake may be exaggerated by the consumption of exogenous opioids (e.g., opioid dependence). Sweet Taste Test (STT) is a validated quantitative instrument assessing taste perception and hedonic features of sugar (sucrose) using a randomized and double-blind administration at five different sucrose concentrations ranging from 0.05 to 0.83 M.

METHODS

The STT and cue-induced craving procedure were administered to opioid-dependent patients (n = 15) before and 1 week after the injection of a long-acting depot naltrexone (XRNT) preparation.

RESULTS

Analyses of covariance, employing sucrose concentration and its perceived taste as covariates, showed that XRNT therapy significantly reduced the self-reported hedonic and motivational characteristics of sucrose. Greater reductions in both these characteristics were associated with more diminution in the cue-induced opioid craving.

CONCLUSIONS

Opioid antagonism in opioid-dependent subjects leads to a smaller sweet taste reward, which, in turn, may be proportional to decreased opioid craving. These pilot results support the heuristic value of the STT as a potential marker of the XRNT treatment response and call for further inquiry into potential clinical applications of the test.

Reduced striatal activation during reward anticipation due to appetite-provoking cues in chronic schizophrenia: a fMRI study

The occurrence of weight gain in schizophrenia (SZ) has profound clinical impact and interacts with antipsychotic medication, life style and disease severity. The functional neuroanatomy underlying altered nutritional behavior is unraveled, but dysregulated reward anticipation might be one of the involved neuronal mechanisms. The striatum, a core region of the reward network and salience attribution, was previously shown to regulate appetite perception and eating behavior. We studied patients suffering from chronic schizophrenia with a stable medication in comparison to age and gender matched healthy adults. Every subject had to undergo a 6h fasting period before a newly developed, appetite-provoking fMRI task was applied. Subjects saw visual stimuli of appetitive food items in a 3Tesla scanner. In healthy controls food images elicited stronger activation in the striatum compared to SZ patients. When adjusting a ROI-based striatal activation for medication and weight, the group difference remained still significant. This points an effect of illness independent of antipsychotic medication. These data underscore the involvement of the striatum into salience attribution, reward anticipation and the neuronal pathways leading to altered eating behavior and weight gain in schizophrenia.

Cognitive deficits, obesity and disability in schizophrenia

Despite 50 years of pharmacological and psychosocial interventions schizophrenia remains one of the leading causes of disability. The inability to function in everyday settings includes deficits in performance of social, occupational, and independent living activities. Schizophrenia is also a life-shortening illness, caused mainly by poor physical health and its complications. Dysfunctional lifestyles including sedentary behavior and lack of physical activity prevail, while treatment with adipogenic antipsychotic medication interacts with poor performance in screening, monitoring, and intervention that result in shortening of life expectancies by 25–30 years. Disability interferes with self-care and medical care, further worsening physical health to produce a vicious cycle of disability. Further, the neurobiological impact of obesity on brain functioning is substantial and relevant to schizophrenia. Decision making deficits that lead to choices resulting in obesity themselves have neurobiological determinants. Simultaneous treatment of cognitive deficits and related deficits in functional skills, ubiquitous determinants of everyday functioning in schizophrenia, and targeted interventions aimed at poor physical health, especially obesity and associated comorbidities, may lead to additive or even interactive gains in everyday functioning in patients with schizophrenia not previously realized with other interventions.

Pharmacogenetics of leptin in antipsychotic-associated weight gain and obesity-related complications

Second-generation antipsychotics can greatly improve symptoms of psychosis-spectrum disorders. Unfortunately, these drugs are associated with weight gain, which increases a patient's risk for developing chronic diseases including Type 2 diabetes, cardiovascular diseases or other obesity-related complications. There are interindividual differences in weight gain resulting from antipsychotic drug use that may be explained by pharmacodynamic characteristics of these agents as well as clinical factors. In addition, genetic variations in pathways associated with satiety are increasingly recognized as potential contributors to antipsychotic-associated weight gain. Polymorphisms in the leptin gene, as well as the leptin receptor gene, are potential pharmacogenetic markers associated with these outcomes. This article summarizes evidence for the associations of the leptin gene and the leptin receptor gene polymorphisms with antipsychotic-induced weight gain, potential mechanisms underlying these relationships, and discusses areas for future pharmacogenetic investigation.

Expression of the neuregulin receptor ErbB4 in the brain of the rhesus monkey (Macaca mulatta)

We demonstrated recently that frontal cortical expression of the Neuregulin (NRG) receptor ErbB4 is restricted to interneurons in rodents, macaques, and humans. However, little is known about protein expression patterns in other areas of the brain. In situ hybridization studies have shown high ErbB4 mRNA levels in various subcortical areas, suggesting that ErbB4 is also expressed in cell types other than cortical interneurons. Here, using highly-specific monoclonal antibodies, we provide the first extensive report of ErbB4 protein expression throughout the cerebrum of primates. We show that ErbB4 immunoreactivity is high in association cortices, intermediate in sensory cortices, and relatively low in motor cortices. The overall immunoreactivity in the hippocampal formation is intermediate, but is high in a subset of interneurons. We detected the highest overall immunoreactivity in distinct locations of the ventral hypothalamus, medial habenula, intercalated nuclei of the amygdala and structures of the ventral forebrain, such as the islands of Calleja, olfactory tubercle and ventral pallidum, and medium expression in the reticular thalamic nucleus. While this pattern is generally consistent with ErbB4 mRNA expression data, further investigations are needed to identify the exact cellular and subcellular sources of mRNA and protein expression in these areas. In contrast to in situ hybridization in rodents, we detected only low levels of ErbB4-immunoreactivity in mesencephalic dopaminergic nuclei but a diffuse pattern of immunofluorescence that was medium in the dorsal striatum and high in the ventral forebrain, suggesting that most ErbB4 protein in dopaminergic neurons could be transported to axons. We conclude that the NRG-ErbB4 signaling pathway can potentially influence many functional systems throughout the brain of primates, and suggest that major sites of action are areas of the “corticolimbic” network. This interpretation is functionally consistent with the genetic association of NRG1 and ERBB4 with schizophrenia.

Might the inability to feel pleasure (anhedonia) explain the symptoms of major depression and schizophrenia, including unmotivated anxiety, delusions and hallucinations?

Inability to enjoy normally pleasurable experiences (anhedonia) is a symptom common both to major depression and schizophrenia. It also regularly accompanies and follows stress, and its presence in the two mental illnesses could depend on the fact that both are facilitated and often preceded by stressful events. Anhedonia might possibly accompany stress because the loss of the pleasure of aiming for a goal and achieving it (including defending oneself and escaping from a danger) could lead to immobility, and immobility (playing dead) offers the extreme chance of safety when an animal is facing the worst possible stressful situation--being seized by a predator--as in this case any movement can further stimulate the predator's aggressiveness. Perceiving and connecting sensory information also gives pleasure, and this appears to enhance the clarity of sensations and is an important factor in learning. We propose that anhedonia, by reducing or eliminating the pleasure, might jeopardize the usual appearance of the environment, which must not only be clearly perceived but also continuously interpreted (for instance a foreshortening, or something far off seen as small, must not be seen as a real deformation; the same holds for words, where the meaning has to be grasped from the single letters, and so on). Consequently, anhedonia could in some cases make the environment's image strange, distorted and frightening, and this could cause anxiety, confusion, and give problems in contacts with people and things. As correct information about images and sounds can inhibit visual and auditory hallucinations (considering them, like delusions, as attempts to reconstruct and make sense again of a world that is becoming confused and alien), we propose that anhedonia, interfering with the correct perceiving and processing of sensations, may facilitate them.

Nucleus accumbens dopamine/glutamate interaction switches modes to generate desire versus dread: D(1) alone for appetitive eating but D(1) and D(2) together for fear

The medial shell of nucleus accumbens (NAc) and its mesolimbic dopamine inputs mediate forms of fearful as well as of incentive motivation. For example, either appetitive and/or actively fearful behaviors are generated in a keyboard pattern by localized glutamate disruptions in NAc (via microinjection of the AMPA receptor antagonist DNQX) at different anatomical locations along a rostrocaudal gradient within the medial shell of rats. Rostral glutamate disruptions produce intense increases in eating, but more caudally placed disruptions produce increasingly fearful behaviors: distress vocalizations and escape attempts to human touch, and a spontaneous and directed antipredator response called defensive treading/burying. Local endogenous dopamine is required for either intense motivation to be generated by AMPA disruptions. Here we report that only endogenous local signaling at D(1) dopamine receptors is needed for rostral generation of excessive eating, potentially implicating a direct output pathway contribution. In contrast, fear generation at caudal sites requires both D(1) and D(2) signaling simultaneously, potentially implicating an indirect output pathway contribution. Finally, when motivation valence generated by AMPA disruptions at intermediate sites was flipped by manipulating environmental ambience, from mostly appetitive in a comfortable home environment to mostly fearful in a stressful environment, the roles of local D(1) and D(2) signaling in dopamine/glutamate interaction at microinjection sites also switched dynamically to match the motivation valence generated at the moment. Thus, NAc D(1) and D(2) receptors, and their associated neuronal circuits, play different and dynamic roles in enabling desire and dread to be generated by localized NAc glutamate disruptions in medial shell.

Is schizophrenia developmental adaptation to environmental menaces?

Schizophrenia is a devastating mental disorder, with its symptoms typically emerging during late adolescence to young adulthood. In contrast, accumulating evidence suggests that schizophrenia is a developmental disorder in which brain abnormalities may occur even before birth. This has brought the major challenge to explain such discrepancy of brain deficits occurring during prenatal period and emergence of symptoms during adulthood. A number of ideas have been proposed to explain delayed emergence of symptoms at adulthood in relation to maturational processes of various brain systems during adolescence. However, these still lack clear relationship to prenatal deficits. Thus, a key to better understand the pathology of schizophrenia is to unveil a theory or model that can explain the relationship between prenatal deficits and post-pubertal onset of symptoms. Here we propose a novel hypothesis, along with discussion of several lines of evidences supporting it, that schizophrenia may not be a disorder in a strict sense, but rather be understood as the biological state occurring as consequence of adaptation to severe environmental conditions during the prenatal periods, which explains the relationship between prenatal developmental deficits and the postnatal maturational process for onset of symptoms.

A transdisciplinary perspective of chronic stress in relation to psychopathology throughout life span development

The allostatic load (AL) model represents an interdisciplinary approach to comprehensively conceptualize and quantify chronic stress in relation to pathologies throughout the life cycle. This article first reviews the AL model, followed by interactions among early adversity, genetics, environmental toxins, as well as distinctions among sex, gender, and sex hormones as integral antecedents of AL. We next explore perspectives on severe mental illness, dementia, and caregiving as unique human models of AL that merit future investigations in the field of developmental psychopathology. A complimenting transdisciplinary perspective is applied throughout, whereby we argue that the AL model goes beyond traditional stress–disease theories toward the advancement of person-centered research and practice that promote not only physical health but also mental health.

Metabolic and endocrine adverse effects of second-generation antipsychotics in children and adolescents: A systematic review of randomized, placebo controlled trials and guidelines for clinical practice

Second-generation antipsychotics (SGA) are being used more often than ever before in children and adolescents with psychotic and a wide range of non-psychotic disorders. Several SGA have received regulatory approval for some paediatric indications in various countries, but off-label use is still frequent. The aim of this paper was to perform a systematic review and critically evaluate the literature on cardiometabolic and endocrine side-effects of SGA in children and adolescents through a Medline/Pubmed/Google Scholar search of randomized, placebo controlled trials of antipsychotics in children and adolescents (<18 years old) until February 2010. In total, 31 randomized, controlled studies including 3595 paediatric patients were identified. A review of these data confirmed that SGA are associated with relevant cardiometabolic and endocrine side-effects, and that children and adolescents have a high liability to experience antipsychotic induced hyperprolactinaemia, weight gain and associated metabolic disturbances. Only weight change data were sufficiently reported to conduct a formal meta-analysis. In 24 trials of 3048 paediatric patients with varying ages and diagnoses, ziprasidone was associated with the lowest weight gain (-0.04kg, 95% confidence interval [CI]: -0.38 to +0.30), followed by aripiprazole (0.79kg, 95% CI: 0.54 to 1.04], quetiapine (1.43kg, 95% CI: 1.17 to 1.69) and risperidone (1.76kg, 95% CI: 1.27 to 2.25) were intermediate, and olanzapine was associated with weight gain the most (3.45kg, 95% CI: 2.93 to 3.97). Significant weight gain appeared to be more prevalent in patients with autistic disorder who were also younger and likely less exposed to antipsychotics previously. These data clearly suggest that close screening and monitoring of metabolic side effects is warranted and that the least cardiometabolically problematic agents should be used first whenever possible. A good collaboration between child- and adolescent psychiatrists, general practitioners and paediatricians is essential to maximize overall outcomes and to reduce the likelihood of premature cardiovascular morbidity and mortality.

Central dopaminergic circuitry controlling food intake and reward: implications for the regulation of obesity

Prevalence of obesity in the general population has increased in the past 15 years from 15% to 35%. With increasing obesity, the coincident medical and social consequences are becoming more alarming. Control over food intake is crucial for the maintenance of body weight and represents an important target for the treatment of obesity. Central nervous system mechanisms responsible for control of food intake have evolved to sense the nutrient and energy levels in the organism and to coordinate appropriate responses to adjust energy intake and expenditure. This homeostatic system is crucial for maintenance of stable body weight over long periods of time of uneven energy availability. However, not only the caloric and nutritional value of food but also hedonic and emotional aspects of feeding affect food intake. In modern society, the increased availability of highly palatable and rewarding (fat, sweet) food can significantly affect homeostatic balance, resulting in dysregulated food intake. This review will focus on the role of hypothalamic and mesolimbic/mesocortical dopaminergic (DA) circuitry in coding homeostatic and hedonic signals for the regulation of food intake and maintenance of caloric balance. The interaction of dopamine with peripheral and central indices of nutritional status (e.g., leptin, ghrelin, neuropeptide Y), and the susceptibility of the dopamine system to prenatal insults will be discussed. Additionally, the importance of alterations in dopamine signaling that occur coincidently with obesity will be addressed.

Neurocircuity of eating disorders

OBJECTIVES

This chapter reviews brain imaging findings in anorexia and bulimia nervosa which characterize brain circuitry that may contribute to the pathophysiology of eating disorders (EDs).

SUMMARY OF RECENT FINDINGS

Recent imaging studies provide evidence of disturbed gustatory processing in EDs which involve the anterior insula as well as striatal regions. These results raise the possibility that individuals with anorexia nervosa have altered appetitive mechanism that may involve sensory, interoceptive, or reward processes. Furthermore, evidence of altered reward mechanisms is supported by studies that suggest that individuals with anorexia nervosa and bulimia nervosa share a trait toward similar anterior ventral striatal pathway dysregulation. This shared trait disturbance of the modulation of reward and emotionality may create a vulnerability for dysregulated appetitive behaviors. However, those with anorexia nervosa may be able to inhibit appetite and have extraordinary self-control because of exaggerated dorsal cognitive circuit function, whereas individuals with bulimia nervosa are vulnerable to overeating when they get hungry, because they have less ability to control their impulses.

FUTURE DIRECTIONS

Current therapeutic interventions have modest success. Better understanding of neurocircuits that may be related to altered appetite, mood, impulse control, and other symptoms underlying the pathophysiology of EDs might improve psychotherapeutic and drug treatment strategies.

The missing p in psychiatric training: why it is important to teach pain to psychiatrists

CONTEXT

Pain problems are exceedingly prevalent among psychiatric patients. Moreover, clinical impressions and neurobiological research suggest that physical and psychological aspects of pain are closely related entities. Nonetheless, remarkably few pain-related themes are currently included in psychiatric residency training.

OBJECTIVES

To provide clinical and scientific rationale for psychiatric-training enrichment with basic tenets of pain medicine and to raise the awareness and sensitivity of physicians, scientists, and educators to this important yet unmet clinical and public health need.

RESULTS

We present 3 lines of translational research evidence, extracted from a comprehensive literature review, in support of our objectives. First, the neuroanatomical and functional overlap between pain and emotion/reward/motivation brain circuitry suggests integration and mutual modulation of these systems. Second, psychiatric disorders are commonly associated with alterations in pain processing, whereas chronic pain may impair emotional and neurocognitive functioning. Third, given its stressful nature, pain may serve as a functional probe for unraveling pathophysiological mechanisms inherent in psychiatric morbidity.

CONCLUSIONS

Pain training in psychiatry will contribute to deeper and more sophisticated insight into both pain syndromes and general psychiatric morbidity regardless of patients' pain status. Furthermore, it will ease the artificial boundaries separating psychiatric and medical formulations of brain disorders, thus fostering cross-fertilizing interactions among specialists in various disciplines entrusted with the care of patients experiencing pain.

Cognitive profile, parental education and BMI in children: reflections on common neuroendrocrinobiological roots

Overweight and obesity may be associated with cognitive problems and both may share "neuroendocrinobiological roots" in common cerebral areas. We investigated intellectual performances and a possible "specific cognitive profile" in overweight/obese children. A cross-sectional study was conducted on 898 school children (6 to 13 years) attending primary schools. Wechsler Intelligence Scale for Children-revised (WISC-R) revealed significant differences in performance intelligence quotient (PIQ) scores between body mass index (BMI) subgroups (p < 0.01). Regression analysis identified BMI as the only variable significantly related to PIQ (p < 0.05). Gender (p < 0.05) and parental educational score (p < 0.001) were significantly related to verbal intelligence quotient (VIQ). Parental educational score was the only factor significantly related to total intelligence quotient (TIQ) (p < 0.05). Parental education seems to play a major role in TIQ and VIQ; a lower PIQ score is clearly related to a higher BMI. A routine neurocognitive assessment in overweight/obese children is recommended. Finally, we have added some reflections on common neuroendocrinobiological roots.

Physical capacity, respiratory quotient and energy expenditure during exercise in male patients with schizophrenia compared with healthy controls

BACKGROUND

Despite massive research on weight gain and metabolic complications in schizophrenia there are few studies on energy expenditure and no current data on physical capacity.

AIM

To determine oxygen uptake capacity, respiratory quotient (RQ) and energy expenditure during a submaximal exercise test in patients with schizophrenia and healthy controls.

METHOD

Ten male patients and 10 controls were included. RQ and energy expenditure were investigated with indirect calorimetry during a cycle ergometer test. The submaximal work level was defined by heart rate and perceived exhaustion. Physical capacity was determined from predicted maximal oxygen uptake capacity (VO(2-max)).

RESULTS

The patients exhibited significantly higher RQ on submaximal workloads and lower physical capacity. A significant lower calculated VO(2-max) remained after correction for body weight and fat free mass (FFM). Energy expenditure did not differ on fixed workloads.

CONCLUSION

RQ was rapidly increasing in the patients during exercise indicating a faster transition to carbohydrate oxidation and anaerobic metabolism that also implies a performance closer to maximal oxygen uptake even at submaximal loads. This may restrict the capacity for everyday activity and exercise and thus contribute to the risk for weight gain. Physical capacity was consequently significantly lower in the patients.

The time-dependent change of insulin secretion in schizophrenic patients treated with olanzapine

The second generation antipsychotic drugs (SGAs) are effective in treating patients with schizophrenia and have been considered as the first line therapy. Recently, increasing attention has been drawn to the potential diabetogenic effect of these novel antipsychotics. The goal of this study was to evaluate the time-dependent effects of olanzapine treatment on pancreatic beta cell function in SGA-naïve schizophrenic patients. Forty-two schizophrenic subjects received olanzapine therapy for 8 weeks and thirty-three of them completed the trial. Of whom 33 completers (21 male, mean+/-SD age: 37.6+/-8.0 years) were inpatients and unexposed to SGA. The metabolic parameters were quantitatively assessed at weeks 0, 2, 4, and 8 by the intravenous glucose tolerance test. After 56-day olanzapine treatment, subjects had significant increases in body weight and as well as in the levels of triglyceride, total cholesterol, and low-density lipoprotein. Insulin secretion significantly decreased at week 2, returned to baseline at week 4, and significantly increased at week 8. Of the total samples, 18.2% and 33.3% of them met the criteria for significant weight gain and metabolic syndrome after 8-week olanzapine treatment, respectively. This study indicates that olanzapine-treated schizophrenic patients displayed biphasic changes in insulin secretion to a hyperglycemic challenge. The results of this study support that olanzapine might directly influence pancreatic beta cell function.

A parametric study of the acute effects of antipsychotic drugs on glucose sensitivity in an animal model

The therapeutic use of atypical antipsychotics is associated with a high incidence of metabolic side-effects. In the present study we examined the acute effects of both high and low-dose atypical antipsychotic drugs and one typical drug on alterations in glucose and insulin parameters using a rodent model. The effects of administration of clozapine (2mg/kg; 20mg/kg), olanzapine (1.5mg/kg; 15 mg/kg), risperidone (0.5mg/kg; 2.5mg/kg) and haloperidol (0.1mg/kg; 1.0mg/kg) on glucose sensitivity and insulin resistance were determined through HOMA-IR values in fasted rats and glucose clearance during a glucose tolerance test. Acute effects were determined 60, 180 or 360 min following drug administration. The atypical antipsychotics produced significant dose and time dependent effects on fasting plasma glucose and insulin concentrations, HOMA-IR values, insulin resistance and glucose intolerance. The greatest effect on glucose dysregulation was noted primarily with clozapine and olanzapine; however, all four treatments caused significant increases in fasting glucose and/or insulin levels with the high dose, 60 min post-drug administration. Together, these findings indicate that acute administration of antipsychotic drugs has potent effects on metabolic regulation of glucose and insulin sensitivities, which may contribute to metabolic side-effects seen in humans.

Relative food preference and hedonic judgments in schizophrenia

There is a well-documented disruption of the neural network associated with reward evaluation in schizophrenia. This same system is involved in coding the incentive value of food in healthy individuals, but few studies to date have examined anhedonia and its relation to food hedonicity and preference in schizophrenia. Relative preference and hedonic food ratings were examined in schizophrenia patients and healthy controls. In the relative preference task, subjects viewed photographs of food items and selected the one that they most preferred. Hedonic ratings were obtained by asking subjects how much they liked the food stimulus on a scale of 1-5. There were no overall response time differences between the two groups in the relative preference task, but schizophrenia patients showed subtle differences in their hedonic ratings of foods compared with control subjects. Schizophrenia patients gave more positive hedonic ratings for food than did controls, and the use of fewer positive ratings was associated with increased anhedonia, particularly with loss of sexual interest. These results suggest that while making relative preference judgments may be intact, hedonic values attached to food may be altered in schizophrenia, and they may be related to dysfunction in more basic vegetative systems.

The d-amphetamine-treated Göttingen miniature pig: an animal model for assessing behavioral effects of antipsychotics

RATIONALE

Rodents are usually used to assess the ability of antipsychotic drugs to antagonize hyperlocomotion induced by dopamine agonists, such as the psychostimulant d-amphetamine. However, the substantial differences between rodents and humans may hinder extrapolation of experimental results to humans. For this reason, we speculated that Göttingen miniature pigs, which show strong physiological and genetic homology with humans, might be a better model for investigating the effects of antipsychotics. To investigate this, we determined whether d-amphetamine induced hyperlocomotion in miniature pigs and whether this effect was reversible by antipsychotics.

MATERIALS AND METHODS

d-amphetamine was tested in the dose range of 0.2 to 2.0 mg kg(-1) for its ability to induce hyperactivity in the open field, and the effects of two antipsychotics, haloperidol and risperidone, on amphetamine-induced hyperactivity were examined.

RESULTS

d-amphetamine increased open-field activity at 0.2, 0.4, and 0.7 mg kg(-1) s.c. but not at higher doses. The stimulation of open-field activity induced by 0.4 mg kg(-1) s.c. d-amphetamine was antagonized by haloperidol and risperidone (0.01 and 0.04 mg kg(-1) s.c.).

CONCLUSION

d-amphetamine-induced hyperlocomotion in miniature pigs may be a useful model for studying the effect of putative antipsychotics.