Addiction and schizophrenia

Modulation of mGlu5 reduces rewarding associative properties of nicotine via changes in mesolimbic plasticity: Relevance to comorbid cigarette smoking in psychosis

RATIONALE

Antipsychotic medications that are used to treat psychosis are often limited in their efficacy by high rates of severe side effects. Treatment success in schizophrenia is further complicated by high rates of comorbid nicotine use. Dopamine D2 heteroreceptor complexes have recently emerged as targets for the development of more efficacious pharmaceutical treatments for schizophrenia.

OBJECTIVE

The current study sought to explore the use of the positive allosteric modulator of the mGlu5 receptor 3-Cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl)benzamide (CDPPB) as a treatment to reduce symptoms related to psychosis and comorbid nicotine use.

METHODS

Neonatal treatment of animals with the dopamine D2-like receptor agonist quinpirole (NQ) from postnatal day (P)1-21 produces a lifelong increase in D2 receptor sensitivity, showing relevance to psychosis and comorbid tobacco use disorder. Following an 8-day conditioning paradigm, brain tissue in the mesolimbic pathway was analyzed for several plasticity markers, including brain derived neurotrophic factor (BDNF), phosphorylated p70 ribosomal S6 kinase (phospho-p70S6K), and cadherin-13 (Cdh13).

RESULTS

Pretreatment with CDPPB was effective to block enhanced nicotine conditioned place preference observed in NQ-treated animals. Pretreatment was additionally effective to block the nicotine-induced increase in BDNF and sex-dependent increases in cadherin-13 in the ventral tegmental area (VTA), as well as increased phospho-p70S6K in the nucleus accumbens (NAcc) shell found in NQ-treated animals.

CONCLUSION

In conjunction with prior work, the current study suggests positive allosteric modulation of the mGlu5 receptor, an emerging target for schizophrenia therapeutics, may be effective for the treatment of comorbid nicotine abuse in psychosis.

Sex differences in prevalence and clinical correlates of internet addiction among Chinese adolescents with schizophrenia

BACKGROUND

Patients with schizophrenia (SCZ) exhibit sex differences in various aspects, and patients with SCZ have a high prevalence of internet addiction (IA). However, sex differences in IA among patients with SCZ mostly remain unstudied, particularly in Chinese adolescent patients with SCZ. This study investigated sex differences in prevalence, risk factors, and clinical correlates of IA among Chinese adolescent patients with SCZ.

METHODS

A total of 706 adolescent patients with SCZ were enrolled in this study using a cross-sectional design and a convenience sampling method. Demographics and clinical data of the patients were collected using a standardized clinical assessment form. The Positive and Negative Syndrome Scale (PANSS) and the Young's Internet Addiction Test were used to evaluate psychopathological symptoms and IA respectively.

RESULTS

Overall, the prevalence of IA among Chinese adolescent patients with SCZ was 26.30% (95% CI: 23.09-29.60%). In Chinese adolescents with SCZ, there was a sex difference in the comorbidity of IA (males: 33.33% vs. females: 21.69%). Binary logistic regression analysis showed that IA was significantly predicted by good socioeconomic status in male and female patients with SCZ. City of living and PANSS total score were associated with IA in male patients with SCZ. In contrast, hospitalization rate and depression score were associated with IA in female patients with SCZ.

CONCLUSION

Our study suggests sex differences in clinical correlates of IA in Chinese adolescent patients with SCZ. An additional longitudinal study is required to confirm the findings of the present study.

Exploring the Association between Schizophrenia and Cardiovascular Diseases: Insights into the Role of Sigma 1 Receptor

Contemporary society is characterized by rapid changes. Various epidemiological, political and economic crises represent a burden to mental health of nowadays population, which may at least partially explain the increasing incidence of mental disorders, including schizophrenia. Schizophrenia is associated with premature mortality by at least 13-15 years. The leading cause of premature mortality in schizophrenia patients is high incidence of cardiovascular diseases. The specific-cause mortality risk for cardiovascular diseases in schizophrenia patients is more than twice higher as compared to the general population. Several factors are discussed as the factor of cardiovascular diseases development. Intensive efforts to identify possible link between schizophrenia and cardiovascular diseases are made. It seems that sigma 1 receptor may represent such link. By modulation of the activity of several neurotransmitter systems, including dopamine, glutamate, and GABA, sigma 1 receptor might play a role in pathophysiology of schizophrenia. Moreover, significant roles of sigma 1 receptor in cardiovascular system have been repeatedly reported. The detailed role of sigma 1 receptor in both schizophrenia and cardiovascular disorders development however remains unclear. The article presents an overview of current knowledge about the association between schizophrenia and cardiovascular diseases and proposes possible explanations with special emphasis on the role of the sigma 1 receptor.

The Hypothalamic-Pituitary-Gonadal Axis in Men with Schizophrenia

Schizophrenia is a severe mental disorder with a chronic, progressive course. The etiology of this condition is linked to the interactions of multiple genes and environmental factors. The earlier age of onset of schizophrenia, the higher frequency of negative symptoms in the clinical presentation, and the poorer response to antipsychotic treatment in men compared to women suggests the involvement of sex hormones in these processes. This article aims to draw attention to the possible relationship between testosterone and some clinical features in male schizophrenic patients and discuss the complex nature of these phenomena based on data from the literature. PubMed, Web of Science, and Google Scholar databases were searched to select the papers without limiting the time of the publications. Hormone levels in the body are regulated by many organs and systems, and take place through the neuroendocrine, hormonal, neural, and metabolic pathways. Sex hormones play an important role in the development and function of the organism. Besides their impact on secondary sex characteristics, they influence brain development and function, mood, and cognition. In men with schizophrenia, altered testosterone levels were noted. In many cases, evidence from available single studies gave contradictory results. However, it seems that the testosterone level in men affected by schizophrenia may differ depending on the phase of the disease, types of clinical symptoms, and administered therapy. The etiology of testosterone level disturbances may be very complex. Besides the impact of the illness (schizophrenia), stress, and antipsychotic drug-induced hyperprolactinemia, testosterone levels may be influenced by, i.a., obesity, substances of abuse (e.g., ethanol), or liver damage.

Dropout Rates in Psychosocial Interventions for People With Both Severe Mental Illness and Substance Misuse: A Systematic Review and Meta-Analysis

INTRODUCTION

Over the years, many psychosocial interventions for individual having both a psychotic spectrum disorder and a substance use disorder diagnoses have been developed and studied. However, there is a high dropout rate among this clinical population.

OBJECTIVES

This meta-analysis aims to replicate a previous meta-analysis on the effects of psychosocial treatment for dual disorders, while including and determining the dropout rates in those type of interventions.

METHOD

Based on a Cochrane systematic review conducted in 2019, we conducted a meta-analysis including 40 randomized clinical trials on psychosocial treatment among persons suffering from schizophrenia spectrum disorder and substance use disorder.

RESULTS

A dropout rate of 27,2% was obtained. Stimulants use significantly affected dropout rates. Age, gender, diagnosis, alcohol and cannabis abuse, and duration of treatment did not affect dropout rates.

CONCLUSION

The 27,2% rate of dropout from psychosocial treatment highlights the need to engage participants having a dual diagnosis from the start by focusing on therapeutic alliance and motivation for treatment.

[Neurodevelopmental Disorders, Psychiatric Comorbidities and Associated Pathologies in Patients with Childhood-Onset Schizophrenia and Premorbid Autistic Symptoms.]

INTRODUCTION

Childhood-Onset Schizophrenia (COS) is a rare (1/40000), severe and neurodevelopmental form of schizophrenia beginning before 13 years of age. Little is known about comorbidities and specific COS-related disorders. Thus, the objective of our study was to evaluate them from a psychiatric, neurodevelopmental and somatic perspective.

METHOD

This is an ancillary study of the GenAuDiss protocol. A standardized psychiatric interview (K-SADS-PL DSM5) and a neuropsychological assessment (WISC-V/WAIS-IV) were carried out in outpatients with COS as well as a medical history collection concerning pregnancy, perinatal period, development, biography and medical and psychiatric, personal, and family history.

RESULTS

20 outpatients were included. The mean age of onset of COS was 8.90 years (+/- 2.30). Psychiatric comorbidities (DSM5) were Attention Deficit Hyperactivity Disorder (15/20 patients), Anxiety Disorders (14/20) and Autism Spectrum Disorder (13/20). The average IQ was 70.26 (+/- 18.09). A language delay and a break in school career were noted in 18/20 patients. Finally, the main associated somatic disorder was asthma (15/20 patients).

DISCUSSION

We highlighted in our patients with COS a high frequency of comorbidities including at least one systematic psychiatric disorder. However, although COS is a severe condition impacting the patient, his family and society, its management remains essentially symptomatic. In clinical practice, it is necessary to look for all these comorbidities and to manage them in order to improve the overall quality of care.

Clinical characteristics of familial schizophrenia

INTRODUCTION

A family history of psychiatric disorders is one of the strongest risk factors for schizophrenia. The characteristics of patients with a family history of psychiatric disorders have not been systematically evaluated.

METHODS

This multicenter study (26 centers, 2425 cases) was performed in a Chinese population to examine the sociodemographic and clinical characteristics of schizophrenia patients with a family history of psychotic disorders in comparison with those of patients with sporadic schizophrenia.

RESULTS

Nineteen percent of patients had a family history of mental disease. Multiple logistic regression analysis revealed that ≥4 hospitalizations (OR = 1.78, P = .004), tobacco dependence (OR = 1.48, P = .006), alcohol dependence (OR = 1.74, P = .013), and physical illness (OR = 1.89, P = .001) were independently and significantly associated with a family history of mental disease.

CONCLUSION

Patients with a family history of mental disorders present different demographics and clinical features than patients without a family history of psychiatric disorders.

microRNA regulation related to the protective effects of environmental enrichment against cocaine-seeking behavior

BACKGROUND

MicroRNAs (miRNAs) are "master post-transcriptional regulators" of gene expression. Here we investigate miRNAs involved in the incentive motivation for cocaine elicited by exposure to cocaine-associated cues.

METHODS

We conducted NanoString nCounter analyses of microRNA expression in the nucleus accumbens shell of male rats that had been tested for cue reactivity in a previous study. These rats had been trained to self-administer cocaine while living in isolate housing, then during a subsequent 21-day forced abstinence period they either stayed under isolate housing or switched to environmental enrichment (EE), as this EE intervention is known to decrease cocaine seeking. This allowed us to create groups of "high" and "low" cocaine seekers using a median split of cocaine-seeking behavior.

RESULTS

Differential expression analysis across high- and low-seekers identified 33 microRNAs that were differentially expressed in the nucleus accumbens shell. Predicted mRNA targets of these microRNAs are implicated in synaptic plasticity, neuronal signaling, and neuroinflammation signaling, and many are known addiction-related genes. Of the 33 differentially-expressed microRNAs, 8 were specifically downregulated in the low-seeking group and another set of 8 had expression levels that were significantly correlated with cocaine-seeking behavior.

CONCLUSION

These findings not only confirm the involvement of previously identified microRNAs (e.g., miR-212, miR-495) but also reveal novel microRNAs (e.g., miR-3557, miR-377) that alter, or are altered by, processes associated with cocaine-seeking behavior. Further research examining the mechanisms involved in these microRNA changes and their effects on signaling may reveal novel therapeutic targets for attenuating drug craving.

Alcohol use in Tanzanians with chronic psychotic disorders and poor medication adherence

Background

The burden of chronic psychotic disorders (CPDs) in sub-Saharan Africa (SSA) is significant. Poorly medically adherent patients are more likely to have worse outcomes and require more resources. However, factors impacting effective treatment of CPD in this population are unclear.

Aim

Examine the relationship between alcohol use and disease management and compare alcohol risk stratification between the Alcohol Use Disorders Identification Test (AUDIT) and Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) in poorly medication adherent Tanzanians with CPD.

Setting

Muhimbili National Hospital and ambulatory clinics in Dar es Salaam, Tanzania.

Methods

100 Tanzanians with CPDs and suboptimal medication adherence were dichotomized into low and moderate-to-high risk alcohol use based on AUDIT scores and compared regarding medication attitudes, adherence and psychiatric symptoms. Patients completed the ASSIST for comparison to AUDIT risk stratification.

Results

Moderate-to-high risk alcohol users had worse medication attitudes (p < 0.01), medication adherence (previous week, p = 0.01; previous month, p < 0.001), and psychiatric symptoms (p = 0.03). They were younger, predominately male and more likely to have a family history of alcohol abuse. A logistic regression analysis found age, gender and family history of abuse as significant predictors of hazardous alcohol use (p = 0.02, 0.02, < 0.01, respectively). Risk stratification between AUDIT and ASSIST aligned in 85% of participants.

Conclusion

Alcohol use is an important consideration in treating poorly adherent Tanzanians with CPD. The ASSIST was comparable to the AUDIT in stratifying risky alcohol use with the additional benefit of screening for other substances.

Problematic Drug Use Among Outpatients With Schizophrenia and Related Psychoses

Background: Problematic drug use is common among psychiatric patients and is linked with poorer course and outcomes of illness. The aim of this study is to assess the prevalence of problematic drug use, and to explore its sociodemographic correlates and associations with health behaviors and outcomes among outpatients with schizophrenia and related psychoses in Singapore. Methods: Data from 397 individuals who were aged 21-65 years and were seeking treatment for schizophrenia and related psychoses in the outpatient clinics of a tertiary psychiatric hospital were analyzed. The Drug Abuse Screening Test (DAST-10) was used to assess problematic drug use. Information on sociodemographics, smoking status, alcohol use, symptoms severity and quality of life were collected. Multivariable logistic regressions were conducted to explore correlates and associations of problematic drug use. Results: The prevalence of problematic drug use was 5.8% (n = 23) in the sample, and 10.6% (n = 42) of the participants reported having problematic drug use and/or problematic alcohol use. More males than females reported having problematic drug use (p = 0.021), and also problematic drug and/or alcohol use (p = 0.004). Significant associations were observed between problematic drug use and smokers with nicotine dependence, and with physical health domain of quality of life. Individuals with greater symptom severity were approximately twice as likely to have problematic drug use and/or alcohol use. Conclusion: While the prevalence of problematic drug use in this sample population is relatively lower compared to other countries, there is a considerable number who might be at risk. Routine screening and close monitoring of drug use is recommended as part of psychiatric assessment, particularly among males and patients with nicotine dependence.

Anxiety and Depression among Amphetamine-Type Stimulant Users: The Association with Religiosity and Religious Coping

BACKGROUND

Amphetamine-type stimulant (ATS) use brings severe adverse effects to the mental well-being of an individual and it is an essential contributor to the global disease burden. Meanwhile, religiosity and religious coping might improve one's conduct, physical and mental well-being. Hence, this study aims to determine the prevalence of anxiety and depression in ATS user and their association with religiosity and religious coping.

METHODS

It is a cross-sectional study conducted at the Department of Psychological Medicine, Universiti Malaya Medical Centre, Malaysia. The Hospital Anxiety and Depression Scale (HADS) was used to assess anxiety and depression among ATS users. Religiosity and religious coping were measured with Duke University Religious Index and Brief RCOPE.

RESULTS

This study involved 215 ATS users. Almost half of the ATS users had either anxiety (n = 96; 44.6%) or depression (n = 108; 50.2%), which were associated with polysubstance use or having an existing psychiatric disorder. Subjects with higher religiosity and positive religious coping were less anxious or depressed. However, negative religious coping was significantly associated with anxiety and depression in ATS users.

CONCLUSION

Anxiety and depression are prevalent in ATS users. Integrating religiosity and religious coping into the ATS users' treatment plan helps to improve their mental well-being.

Schizophrenia in high risk opioid users: A short communication on an autopsy study

The prevalence of schizophrenia among high risk opioid users was investigated as part of a wider investigation into opioid-related deaths. We found that over 6% of our sample of 312 decedents of opioid overdose had received a schizophrenia related diagnosis over a 36 month period prior to their death. This represents a near 8× increase on previously estimated period prevalence of schizophrenia in the general population. Though not conclusive, our findings raise questions about the extent to which opioid drugs are used by people with schizophrenia, and about how to best address high risk opioid use in people with schizophrenia.

Tobacco and Substance Use among Psychiatric Inpatients in a Community Hospital: Cessation Counseling, Correlates, and Patterns of Use

Background

Epidemiological and experimental models have been applied to describe the disproportionately high prevalence of tobacco use in patients with mental illness. This observed association has become a dire public health concern. The main objective of the present study was to examine the provision of tobacco treatment strategies in a community teaching hospital serving a predominantly underserved African American population.

Methods

The study was designed as a retrospective review of eight hundred and thirty patients admitted to the inpatient psychiatric units.

Results

52.2% of the entire cohort described themselves as current smokers. Gender, primary psychiatric diagnosis, and urine toxicology showed significant differences in the tobacco smoking and nontobacco smoking groups (P<0.05). Almost all current tobacco smokers (91.9%) had tobacco cessation counseling during the course of their hospitalization, but only 64% were offered treatments for tobacco dependence. More than half (57.9%) of the 680 participants who had urine toxicology reports were positive for any illicit substance with cannabis and cocaine being the most frequently used (32.4% and 23.2%). Direct logistic regression revealed gender, psychiatric diagnosis, and substance use as the only significant predictors of tobacco smoking among our cohort (P= 0.021, 0.001, and 0.001, respectively).

Conclusions

Tobacco screening, cessation counseling, and treatment continue to be a challenge in community psychiatric hospitals and need increased focus in the comprehensive management of patients with psychiatric disorders. The strong association between tobacco smoking and other substance use lends itself to the hypothesis that tobacco smoking debut prevention may be an effective public health strategy for addressing illicit drug use.

Analyzing the genes related to nicotine addiction or schizophrenia via a pathway and network based approach

The prevalence of tobacco use in people with schizophrenia is much higher than in general population, which indicates a close relationship between nicotine addiction and schizophrenia. However, the molecular mechanism underlying the high comorbidity of tobacco smoking and schizophrenia remains largely unclear. In this study, we conducted a pathway and network analysis on the genes potentially associated with nicotine addiction or schizophrenia to reveal the functional feature of these genes and their interactions. Of the 276 genes associated with nicotine addiction and 331 genes associated with schizophrenia, 52 genes were shared. From these genes, 12 significantly enriched pathways associated with both diseases were identified. These pathways included those related to synapse function and signaling transduction, and drug addiction. Further, we constructed a nicotine addiction-specific and schizophrenia-specific sub-network, identifying 11 novel candidate genes potentially associated with the two diseases. Finally, we built a schematic molecular network for nicotine addiction and schizophrenia based on the results of pathway and network analysis, providing a systematic view to understand the relationship between these two disorders. Our results illustrated that the biological processes underlying the comorbidity of nicotine addiction and schizophrenia was complex, and was likely induced by the dysfunction of multiple molecules and pathways.

Exploration of food addiction in people living with schizophrenia

The term food addiction (FA) denotes a concept among researchers and lay consumers as a behavioural phenotype related to excessive food consumption. In this study we examined the prevalence of FA using the validated Yale Food Addiction Scale (YFAS) as well as the dimensional symptom count. In addition, we explored associations between participant characteristics and FA diagnosis. Outpatients attending a clozapine clinic and possessing a diagnosis of schizophrenia were invited to complete an anonymous survey using the YFAS. Ninety three surveys were used to calculate the diagnostic YFAS criteria for FA. The prevalence of FA found in this sample was 26.9%. Among individuals who did not meet "diagnostic" criteria FA, 77.4% endorsed 3 or more symptoms but did not report distress or impairment. The most common food addiction symptom was a persistent desire or repeated unsuccessful attempts to cut down consumption (97.9%). The significant finding in association between individual's characteristics and diagnosis of FA was employment. Several factors related to reported results are postulated and discussed. The current study has found the prevalence of FA amongst people living with schizophrenia to be higher than the general populations but not as high as populations with disordered eating.

Can symptoms help in differential diagnosis between substance-induced vs independent psychosis in adults with a lifetime diagnosis of cocaine use disorder?

The main goal of this study it is explore the psychopathological differences between IPD and SIPD in a sample of 125 adults with a lifetime diagnosis of cocaine disorder recruited from treatment setting and through street contacts. A secondary analysis of six cross-sectional studies was conducted between 2000 and 2010. SIPD and IPD were diagnosed using the Psychiatric Research Interview for Substance and Mental Disorders (PRISM). 38 subjects (30.4%) were diagnosed with lifetime IPD and 87 (69.6%) with lifetime SIPD. A binomial logistic regression analysis using SIPD as the reference group showed that only previous prison admissions (OR 2.59; 95% CI 1.05, 6.36) and visual hallucinations (OR 5.21; 95% CI 1.54, 17.65) remained significant variables in the group with lifetime SIPD. In the group with lifetime IPD, grandiose delusions (OR 0.19; 95% CI 0.06, 0.60) and disorganized speech (OR 0.16; 95% CI 0.04, 0.61) remained significant. Model predicts the diagnosis of lifetime SIPD with a sensitivity of 80.3% and a specificity of 78.2%. This clinical profile of lifetime SIPD could help distinguish between IPD and SIPD among adults with lifetime diagnosis of cocaine disorder.

Risk factors for substances use and misuse among young people in France: What can we learn from the Substance Use Risk Profile Scale?

BACKGROUND

The prevention of addictions in young people is a challenge for Mental and Public Health policies, and requires specific risk-screening tools. Specific personality traits, as assessed using the Substance Use Risk Profile Scale (SURPS), could play a key role in the onset and escalation of substance use. This study aimed to examine (1) measurement invariance across age and gender (2) the effects of age and gender on associations between SURPS scores and the most frequently-consumed substances.

METHODS

Analyses were based on the responses from 5069 participants (aged 14-20 years) from the 2011 ESPAD-France dataset. Substance-use outcomes were experimentation and current frequency of alcohol, tobacco and cannabis use, and drunkenness.

RESULTS

Our approach, consisting in analysing measurement and structural invariance and interaction terms, established the stability of (i) SURPS profiles, and (ii) relationships between these scores and substance experimentation and use over a developmental period ranging from mid-adolescence to early adulthood. Measurement invariance across genders was also confirmed despite the absence of scalar invariance for 2 items. Significant interactions between gender and SURPS factors were established, highlighting differential vulnerability, especially concerning Hopelessness and experimentation of alcohol and drunkenness, or Impulsivity and tobacco experimentation. Finally, Anxiety Sensitivity could be protective against substance use, especially for cannabis in girls.

CONCLUSIONS

Our results suggest the relevance of the SURPS to assess vulnerability towards drug use, and underline the need to consider gender differences in addiction risks.

ZNF804A variants confer risk for heroin addiction and affect decision making and gray matter volume in heroin abusers

Drug addiction shares common neurobiological pathways and risk genes with other psychiatric diseases, including psychosis. One of the commonly identified risk genes associated with broad psychosis has been ZNF804A. We sought to test whether psychosis risk variants in ZNF804A increase the risk of heroin addiction by modulating neurocognitive performance and gray matter volume (GMV) in heroin addiction. Using case-control genetic analysis, we compared the distribution of ZNF804A variants (genotype and haplotype) in 1035 heroin abusers and 2887 healthy subjects. We also compared neurocognitive performance (impulsivity, global cognitive ability and decision-making ability) in 224 subjects and GMV in 154 subjects based on the ZNF804A variants. We found significant differences in the distribution of ZNF804A intronic variants (rs1344706 and rs7597593) allele and haplotype frequencies between the heroin and control groups. Decision-making impairment was worse in heroin abusers who carried the ZNF804A risk allele and haplotype. Subjects who carried more risk alleles and haplotypes of ZNF804A had greater GMV in the bilateral insular cortex, right temporal cortex and superior parietal cortex. The interaction between heroin addiction and ZNF804A variants affected GMV in the left sensorimotor cortex. Our findings revealed several ZNF804A variants that were significantly associated with the risk of heroin addiction, and these variants affected decision making and GMV in heroin abusers compared with controls. The precise neural mechanisms that underlie these associations are unknown, which requires future investigations of the effects of ZNF804A on both dopamine neurotransmission and the relative increases in the volume of various brain areas.

Polygenic risk score prediction of antipsychotic dosage in schizophrenia

OBJECTIVE

Genetic variants have yet to be identified as reliable predictors of antipsychotic dosage. The purpose of this study is to quantify significant genetic risk variants prioritized from the Psychiatric GWAS Consortium (PGC2) study for schizophrenia as a polygenic score to test our hypothesis that it may represent symptom severity in patients and therefore predict antipsychotic dosage.

METHODS

Antipsychotic medication and dosage were collected in our sample of 83 patients with schizophrenia spectrum disorders of a homogeneous European background. Antipsychotic dosage was standardized according to the Product Monograph (PM%), chlorpromazine equivalents (CPZe), and Defined Daily Dose (DDD). We calculated polygenic risk scores (PRS) for the significant risk loci identified from the PGC2 GWAS to predict dosage using a linear regression model.

RESULTS

In our analysis, the PRS showed no significant association with PM%, CPZe, and DDD dosage. Considering symptom severity and overall functioning, our PRS was similarly not significantly associated with Global Assessment of Functioning (GAF) scores.

DISCUSSION

Our results do not provide evidence for a polygenic inheritance of schizophrenia that influences levels of antipsychotic dosage. To the best of our knowledge, this is one of the first studies of its kind to use the PRS from the PGC2 significant risk variants to predict a clinically relevant phenotype. The PRS offers a novel approach to analyzing the genetic liability for many clinically relevant phenotypes in schizophrenia.

GABRB2 Haplotype Association with Heroin Dependence in Chinese Population

Substance dependence is a frequently observed comorbid disorder in schizophrenia, but little is known about genetic factors possibly shared between the two psychotic disorders. GABRB2, a schizophrenia candidate gene coding for GABAA receptor β2 subunit, is examined for possible association with heroin dependence in Han Chinese population. Four single nucleotide polymorphisms (SNPs) in GABRB2, namely rs6556547 (S1), rs1816071 (S3), rs18016072 (S5), and rs187269 (S29), previously associated with schizophrenia, were examined for their association with heroin dependence. Two additional SNPs, rs10051667 (S31) and rs967771 (S32), previously associated with alcohol dependence and bipolar disorder respectively, were also analyzed. The six SNPs were genotyped by direct sequencing of PCR amplicons of target regions for 564 heroin dependent individuals and 498 controls of Han Chinese origin. Interestingly, it was found that recombination between the haplotypes of all-derived-allele (H1; OR = 1.00) and all-ancestral-allele (H2; OR = 0.74) at S5-S29 junction generated two recombinants H3 (OR = 8.51) and H4 (OR = 5.58), both conferring high susceptibility to heroin dependence. Additional recombination between H2 and H3 haplotypes at S1-S3 junction resulted in a risk-conferring haplotype H5 (OR = 1.94x109). In contrast, recombination between H1 and H2 haplotypes at S3-S5 junction rescued the risk-conferring effect of recombination at S5-S29 junction, giving rise to the protective haplotype H6 (OR = 0.68). Risk-conferring effects of S1-S3 and S5-S29 crossovers and protective effects of S3-S5 crossover were seen in both pure heroin dependent and multiple substance dependence subgroups. In conclusion, significant association was found with haplotypes of the S1-S29 segment in GABRB2 for heroin dependence in Han Chinese population. Local recombination was an important determining factor for switching haplotypes between risk-conferring and protective statuses. The present study provide evidence for the schizophrenia candidate gene GABRB2 to play a role in heroin dependence, but replication of these findings is required.

Negative affective states and cognitive impairments in nicotine dependence

Smokers have substantial individual differences in quit success in response to current treatments for nicotine dependence. This observation may suggest that different underlying motivations for continued tobacco use across individuals and nicotine cessation may require different treatments in different individuals. Although most animal models of nicotine dependence emphasize the positive reinforcing effects of nicotine as the major motivational force behind nicotine use, smokers generally report that other consequences of nicotine use, including the ability of nicotine to alleviate negative affective states or cognitive impairments, as reasons for continued smoking. These states could result from nicotine withdrawal, but also may be associated with premorbid differences in affective and/or cognitive function. Effects of nicotine on cognition and affect may alleviate these impairments regardless of their premorbid or postmorbid origin (e.g., before or after the development of nicotine dependence). The ability of nicotine to alleviate these symptoms would thus negatively reinforce behavior, and thus maintain subsequent nicotine use, contributing to the initiation of smoking, the progression to dependence and relapse during quit attempts. The human and animal studies reviewed here support the idea that self-medication for pre-morbid and withdrawal-induced impairments may be more important factors in nicotine addiction and relapse than has been previously appreciated in preclinical research into nicotine dependence. Given the diverse beneficial effects of nicotine under these conditions, individuals might smoke for quite different reasons. This review suggests that inter-individual differences in the diverse effects of nicotine associated with self-medication and negative reinforcement are an important consideration in studies attempting to understand the causes of nicotine addiction, as well as in the development of effective, individualized nicotine cessation treatments.

Hippocampal cannabinoid transmission modulates dopamine neuron activity: impact on rewarding memory formation and social interaction

Disturbances in cannabinoid type 1 receptor (CB1R) signaling have been linked to emotional and cognitive deficits characterizing neuropsychiatric disorders, including schizophrenia. Thus, there is growing interest in characterizing the relationship between cannabinoid transmission, emotional processing, and dopamine (DA)-dependent behavioral deficits. The CB1R is highly expressed in the mammalian nervous system, particularly in the hippocampus. Activation of the ventral hippocampal subregion (vHipp) is known to increase both the activity of DAergic neurons located in the ventral tegmental area (VTA) and DA levels in reward-related brain regions, particularly the nucleus accumbens (NAc). However, the possible functional relationship between hippocampal CB1R transmission and VTA DA neuronal activity is not currently understood. In this study, using in vivo neuronal recordings in rats, we demonstrate that activation of CB1R in the vHipp strongly increases VTA DA neuronal firing and bursting activity, while simultaneously decreasing the activity of VTA non-DA neurons. Furthermore, using a conditioned place preference procedure and a social interaction test, we report that intra-vHipp CB1R activation potentiates the reward salience of normally sub-threshold conditioning doses of opiates and induces deficits in natural sociability and social recognition behaviors. Finally, these behavioral effects were prevented by directly blocking NAc DAergic transmission. Collectively, these findings identify hippocampal CB1R transmission as a critical modulator of the mesolimbic DA pathway and in the processing of reward and social-related behavioral phenomena.

Nicotine exposure during adolescence: cognitive performance and brain gene expression in adult heterozygous reeler mice

RATIONALE

We have recently reported nicotine-induced stimulation of reelin and glutamic acid decarboxylase 67 (GAD67) mRNA expression levels in the brain of heterozygous reeler mice (HRM), a putative animal model for the study of symptoms relevant to major behavioral disorders.

OBJECTIVES

We aimed to evaluate long-term behavioral effects and brain molecular changes as a result of adaptations to nicotine exposure in the developing HRM males.

METHODS

Adolescent mice (pnd 37-42) were exposed to oral nicotine (10 mg/l) in a 6-day free-choice drinking schedule. As expected, no differences in total nicotine intake between WT (wild-type) mice and HRM were found.

RESULTS

Long-term behavioral effects and brain molecular changes, as a consequence of nicotine exposure during adolescence, were only evidenced in HRM. Indeed, HRM perseverative exploratory behavior and poor cognitive performance were modulated to WT levels by subchronic exposure to nicotine during development. Furthermore, the expected reduction in the expression of mRNA of reelin and GAD67 in behaviorally relevant brain areas of HRM appeared persistently restored by nicotine. For brain-derived neurotrophic factor (BDNF) mRNA expression, no genotype-dependent changes appeared. However, expression levels were increased by previous nicotine in brains from both genotypes. The mRNA encoding for nicotine receptor subunits (α7, β2 and α4) did not differ between genotypes and as a result of previous nicotine exposure.

CONCLUSION

These findings support the hypothesis of pre-existing vulnerability (based on haploinsufficiency of reelin) to brain and behavioral disorders and regulative short- and long-term effects associated with nicotine modulation.

Aripiprazole in an animal model of chronic alcohol consumption and dopamine D₂ receptor occupancy in rats

BACKGROUND

Epidemiologic studies and clinical assessment of schizophrenic population have revealed a high incidence of overlap between schizophrenia and addictive disorders.

OBJECTIVE

The aim of the present investigation was to study the effect of aripiprazole in a preclinical animal model of chronic alcohol self-administration (CASA) and also to evaluate the influence of CASA on plasma pharmacokinetics and dopamine D₂ receptor (D₂R) occupancy in rats.

METHODS

The effect of oral administration of aripiprazole (1, 3, and 10 mg/kg) on 4% alcohol intake in CASA was studied for a period of 45 min after a post-dosing interval of 60 min. Brain penetration, pharmacokinetics, and D₂R occupancy of aripiprazole were evaluated in normal and CASA rats.

RESULTS

Aripiprazole reduced alcohol consumption in CASA rats by 13, 28, and 86% at 1, 3, and 10 mg/kg, respectively, and the effect reached statistical significance at 10 mg/kg (p < .01). At this behavioral effective dose, a decrease (75%) in total plasma apparent clearance and an increase in oral area under the concentration-time curve (3.98-fold) and bioavailability (3.50-fold) of aripiprazole was observed in CASA rats. Striatal D₂R occupancy and brain exposure of aripiprazole were significantly higher (∼twofold) in CASA rats when compared to normal rats (p < .01).

CONCLUSION

Chronic alcohol intake results in a significant increase in exposure of aripiprazole in plasma and brain and striatal D₂R occupancy.

SCIENTIFIC SIGNIFICANCE

Chronic alcohol intake would increase aripiprazole exposure, thus aripiprazole dose might have to be decreased (assuming this same phenomenon occurs in humans).

Increased mortality in schizophrenia due to cardiovascular disease - a non-systematic review of epidemiology, possible causes, and interventions

BACKGROUND

Schizophrenia is among the major causes of disability worldwide and the mortality from cardiovascular disease (CVD) is significantly elevated. There is a growing concern that this health challenge is not fully understood and efficiently addressed.

METHODS

Non-systematic review using searches in PubMed on relevant topics as well as selection of references based on the authors' experience from clinical work and research in the field.

RESULTS

In most countries, the standardized mortality rate in schizophrenia is about 2.5, leading to a reduction in life expectancy between 15 and 20 years. A major contributor of the increased mortality is due to CVD, with CVD mortality ranging from 40 to 50% in most studies. Important causal factors are related to lifestyle, including poor diet, lack of physical activity, smoking, and substance abuse. Recent findings suggest that there are overlapping pathophysiology and genetics between schizophrenia and CVD-risk factors, further increasing the liability to CVD in schizophrenia. Many pharmacological agents used for treating psychotic disorders have side effects augmenting CVD risk. Although several CVD-risk factors can be effectively prevented and treated, the provision of somatic health services to people with schizophrenia seems inadequate. Further, there is a sparseness of studies investigating the effects of lifestyle interventions in schizophrenia, and there is little knowledge about effective programs targeting physical health in this population.

DISCUSSION

The risk for CVD and CVD-related deaths in people with schizophrenia is increased, but the underlying mechanisms are not fully known. Coordinated interventions in different health care settings could probably reduce the risk. There is an urgent need to develop and implement effective programs to increase life expectancy in schizophrenia, and we argue that mental health workers should be more involved in this important task.

Thought disorder in the meta-structure of psychopathology

BACKGROUND

Dimensional models of co-morbidity have the potential to improve the conceptualization of mental disorders in research and clinical work, yet little is known about how relatively uncommon disorders may fit with more common disorders. The present study estimated the meta-structure of psychopathology in the US general population focusing on the placement of five under-studied disorders sharing features of thought disorder: paranoid, schizoid, avoidant and schizotypal personality disorders, and manic episodes as well as bipolar disorder.

METHOD

Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions, a face-to-face interview of 34 653 non-institutionalized adults in the US general population. The meta-structure of 16 DSM-IV Axis I and Axis II psychiatric disorders, as assessed by the Alcohol Use Disorder and Associated Disabilities Interview Schedule DSM-IV version (AUDADIS-IV), was examined using exploratory and confirmatory factor analysis.

RESULTS

We document an empirically derived thought disorder factor that is a subdomain of the internalizing dimension, characterized by schizoid, paranoid, schizotypal and avoidant personality disorders as well as manic episodes. Manic episodes exhibit notable associations with both the distress subdomain of the internalizing dimension as well as the thought disorder subdomain. The structure was replicated for bipolar disorder (I or II) in place of manic episodes.

CONCLUSIONS

As our understanding of psychopathological meta-structure expands, incorporation of disorders characterized by detachment and psychoticism grows increasingly important. Disorders characterized by detachment and psychoticism may be well conceptualized, organized and measured as a subdimension of the internalizing spectrum of disorders. Manic episodes and bipolar disorder exhibit substantial co-morbidity across both distress and thought disorder domains of the internalizing dimension. Clinically, these results underscore the potential utility of conceptualizing patient treatment needs using an approach targeting psychopathological systems underlying meta-structural classification rubrics.

From passive overeating to "food addiction": a spectrum of compulsion and severity

A psychobiological dimension of eating behaviour is proposed, which is anchored at the low end by energy intake that is relatively well matched to energy output and is reflected by a stable body mass index (BMI) in the healthy range. Further along the continuum are increasing degrees of overeating (and BMI) characterized by more severe and more compulsive ingestive behaviours. In light of the many similarities between chronic binge eating and drug abuse, several authorities have adopted the perspective that an apparent dependence on highly palatable food-accompanied by emotional and social distress-can be best conceptualized as an addiction disorder. Therefore, this review also considers the overlapping symptoms and characteristics of binge eating disorder (BED) and models of food addiction, both in preclinical animal studies and in human research. It also presents this work in the context of the modern and "toxic" food environment and therein the ubiquitous triggers for over-consumption. We complete the review by providing evidence that what we have come to call "food addiction" may simply be a more acute and pathologically dense form of BED.

The impact of copy number deletions on general cognitive ability and ventricle size in patients with schizophrenia and healthy control subjects

BACKGROUND

General cognitive ability is usually lower in individuals with schizophrenia, partly due to genetic influences. However, the specific genetic features related to general cognitive ability are poorly understood. Individual variation in a specific type of mutation, uncommon genetic deletions, has recently been linked with both general cognitive ability and risk for schizophrenia.

METHODS

We derived measures of the aggregate number of "uncommon" deletions (i.e., those occurring in 3% or less of our combined samples) and the total number of base pairs affected by these deletions in individuals with schizophrenia (n = 79) and healthy control subjects (n = 110) and related each measure to the first principal component of a large battery of cognitive tests, a common technique for characterizing general cognitive ability. These two measures of mutation load were also evaluated for relationships with total brain gray matter, white matter, and lateral ventricle volume.

RESULTS

The groups did not differ on genetic variables. Multivariate general linear models revealed a group (control subjects vs. patients) × uncommon deletion number interaction, such that the latter variable was associated with lower general cognitive ability and larger ventricles in patients but not control subjects.

CONCLUSIONS

These data suggest that aggregate uncommon deletion burden moderates central features of the schizophrenia phenotype.

Neuroethical issues in clinical neuroscience research

In this chapter, we use the special features of neuroimaging to illustrate research ethics issues for the clinical neurologic sciences, and focus on one particularly compelling case: studies involving first-episode schizophrenic treatment-naïve individuals (FESTNIs) (Eijkholt et al., 2012). FESTNIs are scanned prior to the administration of medication in order to control for the confounding effects of treatment. By concentrating on this program of research, we capture the distinctive ethical challenges associated with neuroimaging research overall, and foreground the issues particular to neuroimaging research involving FESTNIs that have yet to receive sufficient attention in the literature. We highlight assessment of risks and burdens, including risks associated with treatment delays and incidental findings; assessment of benefit, including direct benefit, social value, and scientific quality; subject selection; justice questions related to responsiveness and poststudy access; and, finally, issues related to consent and capacity.

Optogenetic investigation of neural circuits underlying brain disease in animal models

Optogenetic tools have provided a new way to establish causal relationships between brain activity and behaviour in health and disease. Although no animal model captures human disease precisely, behaviours that recapitulate disease symptoms may be elicited and modulated by optogenetic methods, including behaviours that are relevant to anxiety, fear, depression, addiction, autism and parkinsonism. The rapid proliferation of optogenetic reagents together with the swift advancement of strategies for implementation has created new opportunities for causal and precise dissection of the circuits underlying brain diseases in animal models.

Picturing neuroscience research through a human rights lens: imaging first-episode schizophrenic treatment-naive individuals

In this paper we examine imaging research involving first-episode schizophrenic treatment-naive individuals (FESTNIs) through a legal human rights lens; in particular, the lens of the Additional Protocol to the Convention on Human Rights and Biomedicine Concerning Biomedical Research. We identify a number of ethical and legal hot spots highlighted by the Protocol, and offer a series of recommendations designed to ensure the human rights compatibility of this research. Subsequently, we argue that the lack of reporting on design elements related to ethical concerns frustrates commitments at the heart of the human rights approach, namely, transparency and openness to international scrutiny. To redress this problem, we introduce two norms for the first time: ethical transparency, and ethical reproducibility. When concluding, we offer a set of reporting guidelines designed to operationalize these norms in the context of imaging research involving FESTNIs. Though we will not make this case here, we believe that parallel reporting guidelines should be incorporated into other areas of research involving human subjects.

Pathological gambling in a psychiatric sample

OBJECTIVE

This study determines the prevalence of gambling difficulties in a consecutive sample of psychiatric inpatients and compares it with a nonpsychiatric inpatient sample. In addition, the gambling prevalence among all psychiatric disorders is analyzed.

METHOD

An observational study was conducted in psychiatric patients and sex- and age-matched nonpsychiatric patients. The psychiatric group (n = 100) included all consecutive patients admitted to the psychiatric unit of our hospital. The nonpsychiatric group (n = 100) included psychiatrically healthy inpatients from any other hospital unit. The National Opinion Research Center Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Screen for Gambling Problems was used to screen for gambling behavior.

RESULTS

Gambling difficulties were experienced by 3% (2% pathological gambling and 1% problem gambling) of nonpsychiatric inpatients and 9% (8% pathological gambling and 1% problem gambling) of psychiatric inpatients, including 6 with psychotic disorders, 1 with mood disorder, 1 with adjustment disorder, and 1 with eating disorder. There were no statistical differences in gambling prevalence between groups. In terms of comorbidity, patients with psychotic disorder had a higher prevalence of gambling problems than other psychiatric disorders (P = .045).

CONCLUSIONS

A higher prevalence of gambling disorders was found in psychiatric inpatients than in nonpsychiatric inpatients. It may be advisable for therapists to routinely assess for gambling difficulties as part of the psychiatric evaluation.

ACSL6 is associated with the number of cigarettes smoked and its expression is altered by chronic nicotine exposure

Individuals with schizophrenia tend to be heavy smokers and are at high risk for tobacco dependence. However, the nature of the comorbidity is not entirely clear. We previously reported evidence for association of schizophrenia with SNPs and SNP haplotypes in a region of chromosome 5q containing the SPEC2, PDZ-GEF2 and ACSL6 genes. In this current study, analysis of the control subjects of the Molecular Genetics of Schizophrenia (MGS) sample showed similar pattern of association with number of cigarettes smoked per day (numCIG) for the same region. To further test if this locus is associated with tobacco smoking as measured by numCIG and FTND, we conducted replication and meta-analysis in 12 independent samples (n>16,000) for two markers in ACSL6 reported in our previous schizophrenia study. In the meta-analysis of the replication samples, we found that rs667437 and rs477084 were significantly associated with numCIG (p = 0.00038 and 0.00136 respectively) but not with FTND scores. We then used in vitro and in vivo techniques to test if nicotine exposure influences the expression of ACSL6 in brain. Primary cortical culture studies showed that chronic (5-day) exposure to nicotine stimulated ACSL6 mRNA expression. Fourteen days of nicotine administration via osmotic mini pump also increased ACSL6 protein levels in the prefrontal cortex and hippocampus of mice. These increases were suppressed by injection of the nicotinic receptor antagonist mecamylamine, suggesting that elevated expression of ACSL6 requires nicotinic receptor activation. These findings suggest that variations in the ACSL6 gene may contribute to the quantity of cigarettes smoked. The independent associations of this locus with schizophrenia and with numCIG in non-schizophrenic subjects suggest that this locus may be a common liability to both conditions.

Carbohydrate reward and psychosis: an explanation for neuroleptic induced weight gain and path to improved mental health?

Evidence links dopamine release in the mid-brain to the pathophysiology of psychosis, addiction and reward. Repeated ingestion of refined carbohydrate may stimulate the same mesolimbic dopaminergic pathway, rewarding such eating behaviour and resulting in excessive food intake along with obesity. In this paper, we explore the role of dopamine in reward and psychosis, and discuss how reward pathways may contribute to the weight gain that commonly follows antipsychotic drug use, in people with psychotic illness. Our theory also explains the frequent co-occurrence of substance abuse and psychosis. From our hypothesis, we discuss the use of carbohydrate modified diets as an adjunctive treatment for people with psychosis.

Effects of risperidone, quetiapine and ziprasidone on ethanol withdrawal syndrome in rats

Comorbid substance use in schizophrenic patients is common, and substance dependence is a predictive factor for psychosis. The present study was designed to investigate the effects of risperidone, quetiapine and ziprasidone, atypical antipsychotic drugs, on ethanol withdrawal syndrome (EWS) in rats. Adult male Wistar rats were used in the study. Ethanol (7.2%, v/v) was given to rats via a liquid diet for 21 days. An isocaloric liquid diet without ethanol was given to control rats. Risperidone (1 and 2 mg/kg), quetiapine (8 and 16 mg/kg), ziprasidone (0.5 and 1 mg/kg) and vehicle were injected into rats intraperitoneally at 1.5 and 5.5 h of ethanol withdrawal. At the 2nd, 4th and 6th hours of ethanol withdrawal, rats were observed for 5 min, and withdrawal signs that included locomotor hyperactivity, stereotyped behaviors, abnormal gait and posture, tail stiffness and agitation were recorded or rated. Following the observations at the 6th hour, the rats were tested for audiogenic seizures. All three drugs had some significant inhibitory effects on EWS-induced behavioral signs beginning at the 2nd hour of withdrawal. The drugs also significantly reduced the incidence of audiogenic seizures. Overall, risperidone and quetiapine seemed to be more effective than ziprasidone in ameliorating the withdrawal signs. Doses of the drugs used in the present study did not produce any significant changes in locomotor activities of naïve rats. Our results suggest that risperidone, quetiapine and ziprasidone had beneficial effects on EWS in rats. Thus, these drugs may be helpful for controlling withdrawal signs in ethanol-dependent patients.

Effects of risperidone on development and expression of nicotine-induced locomotor sensitization in rats

It has been shown that atypical antipsychotics significantly reduce smoking and alcohol consumption in schizophrenic patients. However, our knowledge about the effect of risperidone, especially on nicotine abuse is limited. We aimed to test the effects of risperidone in an animal model of nicotine-induced locomotor sensitization, which represents initial neuroadaptations and continued behavioral changes in nicotine-type dependence. To investigate the effect of risperidone on the development of nicotine-induced locomotor sensitization, rats were pretreated with risperidone (0.025 and 0.050 mg kg⁻¹) 30 min before the nicotine (0.5 mg kg⁻¹, base) treatment, and locomotor activity was recorded for 30 min. This procedure was repeated every day for eight sessions. After a 6-day drug-free period, rats were challenged with nicotine (0.5 mg kg⁻¹). To reveal the effect of risperidone on the expression of nicotine-induced locomotor sensitization, rats were injected with nicotine for eight sessions. After a 6-day drug-free period, rats were pretreated with risperidone (0.025 and 0.050 mg kg⁻¹) or vehicle 30 min before the nicotine (0.5 mg kg⁻¹) challenge injection. Repeated administration of nicotine generated robust locomotor sensitization in rats. Risperidone pretreatment (0.050 mg kg⁻¹) blocked the expression but not the development of nicotine-induced locomotor sensitization in rats. Our results suggest that risperidone blocks the continuation of nicotine-type addictive behavior, but it is ineffective on early adaptations in the initiation of nicotine addiction. Thus, this drug may have a limited beneficial effect in treatment of nicotine dependence.

Hospital readmission in first-time admitted patients with schizophrenia: smoking patients had higher hospital readmission rate than non-smoking patients

OBJECTIVES

To consider smoke-free policies for the patients with schizophrenia, the present study examined how smoking behavior is related to hospital readmission among patients with schizophrenia.

METHODS

A retrospective study was conducted in 2007 on 460 discharged patients with schizophrenia who voluntarily admitted in the participating psychiatric hospitals at first time. We reviewed smoking status, readmissions, and other variables including socio-demographic characteristics, process of care, and social functioning at discharge using the Global Assessment of Functioning scale (GAF).

RESULTS

The rate of cigarette smoking in this study was 42.2%. The rate of smoking was significantly higher in males (56.1%) than in females (26.2%). Mean GAF score at discharge was slightly higher in smoking patients than non-smoking patients (g = 0.18). Cox proportional hazard model revealed that hospital readmission rate was significantly higher in smoking patients than non-smoking patients after controlling for all other variables (HR = 1.78).

CONCLUSIONS

Non-smoking patients had fewer hospital readmissions than smoking patients. This finding could be a reason to promote cessation of smoking which might provide positive influences on prognosis of schizophrenia.

The relationship between baseline prepulse inhibition levels and ethanol withdrawal severity in rats

Baseline prepulse inhibition (PPI) of the acoustic startle reflex is thought to reflect the functioning of the sensorimotor gating system in the brain. The current literature indicates that similar neurotransmitter systems may play roles both in the regulation of PPI and in the development of ethanol withdrawal syndrome (EWS). The aim of the present study was to test if individual baseline PPI levels have any relationship to the behavioral and neurochemical consequences of EWS in rats. A batch of rats (n=30) was sorted according to baseline PPI levels and classified as either high-inhibitory (HI) or low-inhibitory (LI) rats (n=10 in each group). Ethanol was administered in a liquid diet for 21 days. On the 22nd day, ethanol was removed from the diet, and EWS was induced. At the 2nd, 4th, and 6th hours of EWS, locomotor activity and behavioral symptoms were evaluated. Brain tissue concentrations of dopamine, serotonin and noradrenaline in hippocampus, cortex, and striatum were measured after the 6th hour of EWS testing. Another batch of rats (n=30) was classified using the same procedure and fed with regular diet. On the 22nd day, rats were decapitated and neurochemical measurements were repeated. HI and LI rats consumed similar amounts of ethanol. However, EWS signs such as stereotyped behaviors, wet-dog shakes, and tremor were more intense in LI rats compared to their HI counterparts. Audiogenic seizures occurred in both groups in a similar manner. Although the catecholamine concentrations in the brains of both groups were parallel under baseline conditions, dopamine levels increased in the cortex of LI and in the striatum of HI rats, whereas striatum serotonin levels decreased only in LI rats after the 6th hour of EWS. In conclusion, the data suggest that the behavioral symptoms and neurochemical changes observed in EWS may be associated with baseline PPI levels.

Treatment outcome in patients receiving assertive community treatment

In an observational study of severely mentally ill patients treated in assertive community treatment (ACT) teams, we investigated how treatment outcome was associated with demographic factors, clinical factors, and motivation for treatment. To determine psychosocial outcome, patients were routinely assessed using the Health of the Nation Outcome Scales (HoNOS). Trends over time were analyzed using a mixed model with repeated measures. The HoNOS total score was modeled as a function of treatment duration and patient-dependent covariates. Data comprised 637 assessments of 139 patients; mean duration of follow-up was 27.4 months (SD = 5.4). Substance abuse, higher age, problems with motivation, and lower educational level were associated with higher HoNOS total scores (i.e., worse outcome). To improve treatment outcome, we recommend better implementation of ACT, and also the implementation of additional programs targeting subgroups which seem to benefit less from ACT.

The role of executive control in human drug addiction

Recent neurobiological models propose that executive control deficits play a critical role in the development and maintenance of drug addiction. In this review, we discuss recent advances in our understanding of executive control processes and their constituent neural network, and examine neuropsychological and neuroimaging evidence of executive control dysfunction in addicted drug users. We explore the link between attentional biases to drug-related stimuli and treatment outcome, and discuss recent work demonstrating that the hedonic balance between drug cues and natural reinforcers is abnormal in addiction. Finally, we consider the potential impact of early drug use on the developing adolescent brain, and discuss research examining premorbid executive control impairments in drug-naïve "at-risk" populations.

European network for promoting the physical health of residents in psychiatric and social care facilities (HELPS): background, aims and methods

Background

People with mental disorders have a higher prevalence of physical illnesses and reduced life expectancy as compared with the general population. However, there is a lack of knowledge across Europe concerning interventions that aim at reducing somatic morbidity and excess mortality by promoting behaviour-based and/or environment-based interventions.

Methods and design

HELPS is an interdisciplinary European network that aims at (i) gathering relevant knowledge on physical illness in people with mental illness, (ii) identifying health promotion initiatives in European countries that meet country-specific needs, and (iii) at identifying best practice across Europe. Criteria for best practice will include evidence on the efficacy of physical health interventions and of their effectiveness in routine care, cost implications and feasibility for adaptation and implementation of interventions across different settings in Europe. HELPS will develop and implement a "physical health promotion toolkit". The toolkit will provide information to empower residents and staff to identify the most relevant risk factors in their specific context and to select the most appropriate action out of a range of defined health promoting interventions. The key methods are (a) stakeholder analysis, (b) international literature reviews, (c) Delphi rounds with experts from participating centres, and (d) focus groups with staff and residents of mental health care facilities.

Meanwhile a multi-disciplinary network consisting of 15 European countries has been established and took up the work. As one main result of the project they expect that a widespread use of the HELPS toolkit could have a significant positive effect on the physical health status of residents of mental health and social care facilities, as well as to hold resonance for community dwelling people with mental health problems.

Discussion

A general strategy on health promotion for people with mental disorders must take into account behavioural, environmental and iatrogenic health risks. A European health promotion toolkit needs to consider heterogeneity of mental disorders, the multitude of physical health problems, health-relevant behaviour, health-related attitudes, health-relevant living conditions, and resource levels in mental health and social care facilities.

Presynaptic type III neuregulin 1 is required for sustained enhancement of hippocampal transmission by nicotine and for axonal targeting of alpha7 nicotinic acetylcholine receptors

Both the neuregulin 1 (Nrg1) and alpha7 nicotinic acetylcholine receptor (alpha7*nAChRs) genes have been linked to schizophrenia and associated sensory-motor gating deficits. The prominence of nicotine addiction in schizophrenic patients is reflected in the normalization of gating deficits by nicotine self-administration. To assess the role of presynaptic type III Nrg1 at hippocampal-accumbens synapses, an important relay in sensory-motor gating, we developed a specialized preparation of chimeric circuits in vitro. Synaptic relays from Nrg1(tm1Lwr) heterozygote ventral hippocampal slices to wild-type (WT) nucleus accumbens neurons (1) lack a sustained, alpha7*nAChRs-mediated phase of synaptic potentiation seen in comparable WT/WT circuits and (2) are deficient in targeting alpha7*nAChRs to presynaptic sites. Thus, selective alteration of the level of presynaptic type III Nrg1 dramatically affects the modulation of glutamatergic transmission at ventral hippocampal to nucleus accumbens synapses.

Effects of clozapine on ethanol withdrawal syndrome in rats

AIMS

Co-morbid substance use in schizophrenic patients is common, and an important factor affects the outcome of disease. On the other hand, drug dependence is a predictive factor for psychosis. Alcohol is one of the most frequently abused psychoactive substances and may contribute psychotic symptoms in several conditions, such as withdrawal syndrome. The present study was designed to investigate the effects of clozapine on ethanol withdrawal syndrome (EWS) in rats.

METHODS

Adult male Wistar rats were used in the study. Ethanol (7.2%, v/v) was given to rats by a liquid diet for 14 days. An isocaloric liquid diet without containing ethanol was also given to control rats. Clozapine (2.5, 5 and 10 mg/kg) and its vehicle (0.1% acetic acid) were injected to rats subcutaneously at the 1.5th and 5.5th hours of ethanol withdrawal. At 2nd, 4th and 6th hours of ethanol withdrawal, rats were observed for 5 min and withdrawal signs that included locomotor hyperactivity, agitation, tremor, tail stiffness, stereotyped behaviour and wet dog shakes were recorded or rated. Following the observations at 6th hour, subjects were tested for audiogenic seizures.

RESULTS

Clozapine significantly and dose-dependently inhibited the EWS-induced locomotor hyperactivity, wet dog shake, stereotyped behaviour, tremor and tail stiffness. However, it did not produce any significant effect on agitation and audiogenic seizures. Doses of clozapine used in the present study did not produce any significant change on locomotor activities of naïve rats.

CONCLUSIONS

Our results suggest that clozapine had some significant beneficial effects on EWS in rats. Thus, this drug may be helpful for controlling some withdrawal signs in ethanol-dependent patients.

Microtubule-associated STOP protein deletion triggers restricted changes in dopaminergic neurotransmission

The microtubule-associated stable tubule only polypeptide (STOP) protein plays a key-role in neuron architecture and synaptic plasticity. Recent studies suggest that schizophrenia is associated with alterations in the synaptic connectivity. Mice invalidated for the STOP gene display phenotype reminiscent of some schizophrenic-like symptoms, such as behavioral disturbances, dopamine (DA) hyper-reactivity, and possible hypoglutamatergia, partly improved by antipsychotic treatment. In the present work, we examined potential alterations in some DAergic key proteins and behaviors in STOP knockout mice. Whereas the densities of the DA transporter, the vesicular monoamine transporter and the D(1) receptor were not modified, the densities of the D(2) and D(3) receptors were decreased in some DAergic regions in mutant versus wild-type mice. Endogenous DA levels were selectively decreased in DAergic terminals areas, although the in vivo DA synthesis was diminished both in cell bodies and terminal areas. The DA uptake was decreased in accumbic synaptosomes, but not significantly altered in striatal synaptosomes. Finally, STOP knockout mice were hypersensitive to acute and subchronic locomotor effects of cocaine, although the drug equally inhibited DA uptake in mutant and wild-type mice. Altogether, these data showed that deletion of the ubiquitous STOP protein elicited restricted alterations in DAergic neurotransmission, preferentially in the meso-limbic pathway.