Worse psychological traits associated with higher probability of emotional problems during the Omicron pandemic in Tianjin, China.

Background and Objectives: Individuals with specific psychological weaknesses are prone to mental problems during the coronavirus pandemic. This self-rating study assessed the combined effects of infection-related stress, resilience, worry, and loneliness on the likelihood of depression and anxiety among infected and non-infected individuals during the Tianjin Pandemic in 2022. Methods: Individuals infected with Omicron (n = 249) and health residents (n = 415) were recruited from two hospitals and communities in Tianjin. Each respondent completed the following on-site assessment: Self-developed Scale of Demographics, Zung Self-Rating Depression Scale (SDS), Zung Self-Rating Anxiety Scale (SAS), the Connor-Davidson Resilience Scale (CD-RISC), De Jong Gierveld Scale (DJGLS), and the Penn State Worry Questionnaire (PSWQ). The respondents were categorized into depression or non-depression group by SDS scores, and anxiety or non-anxiety group by SAS scores. Results: The overall scores of CD-RISC, DJGJLS, and PSWQ were significantly different both between the depression group and non-depression groups and between the anxiety group and non-anxiety groups. The greater likelihood of depression was associated with lower overall scores of CD-RISC and higher scores of PSWQ; the greater likelihood of anxiety was associated with higher scores of PSWQ. The likelihood of depression was also positively associated with having infection-related stress and three demographics. Conclusions: This on-site study demonstrates the importance of specific traits in a small-scale pandemic: the worse resilience and the greater worry propensity related to the higher probability of depression, and the greater propensity of worry related to the higher probability of anxiety. Moreover, those experiencing infection-related stress, being male, living alone, and being unemployed are more likely to have depressive problems.

Comparison of social cognition using an adapted Chinese version of the Reading the Mind in the Eyes Test in drug-naive and regularly medicated individuals with chronic schizophrenia and healthy controls in rural China.

BACKGROUND: Social cognition has not previously been assessed in treatment-naive patients with chronic schizophrenia, in patients over 60 years of age, or in patients with less than 5 years of schooling. METHODS: We revised a commonly used measure of social cognition, the Reading the Mind in the Eyes Test (RMET), by expanding the instructions, using both self-completion and interviewer-completion versions (for illiterate respondents), and classifying each test administration as 'successfully completed' or 'incomplete'. The revised instrument (RMET-CV-R) was administered to 233 treatment-naive patients with chronic schizophrenia (UT), 154 treated controls with chronic schizophrenia (TC), and 259 healthy controls (HC) from rural communities in China. RESULTS: In bivariate and multivariate analyses, successful completion rates and RMET-CV-R scores (percent correct judgments about emotion exhibited in 70 presented slides) were highest in HC, intermediate in TC, and lowest in UT (adjusted completion rates, 97.0, 72.4, and 49.9%, respectively; adjusted RMET-CV-R scores, 45.4, 38.5, and 34.6%, respectively; all p < 0.02). Stratified analyses by the method of administration (self-completed v. interviewer-completed) and by education and age ('educated-younger' v. 'undereducated-older') show the same relationship between groups (i.e. NC>TC>UT), though not all differences remain statistically significant. CONCLUSIONS: We find poorer social cognition in treatment-naive than in treated patients with chronic schizophrenia. The discriminant validity of RMET-CV-R in undereducated, older patients demonstrates the feasibility of administering revised versions of RMET to patients who may otherwise be considered ineligible due to education or age by changing the method of test administration and carefully assessing respondents' ability to complete the task successfully.

The magnitude of and health system responses to the mental health treatment gap in adults in India and China.

This Series paper describes the first systematic effort to review the unmet mental health needs of adults in China and India. The evidence shows that contact coverage for the most common mental and substance use disorders is very low. Effective coverage is even lower, even for severe disorders such as psychotic disorders and epilepsy. There are vast variations across the regions of both countries, with the highest treatment gaps in rural regions because of inequities in the distribution of mental health resources, and variable implementation of mental health policies across states and provinces. Human and financial resources for mental health are grossly inadequate with less than 1% of the national health-care budget allocated to mental health in either country. Although China and India have both shown renewed commitment through national programmes for community-oriented mental health care, progress in achieving coverage is far more substantial in China. Improvement of coverage will need to address both supply-side barriers and demand-side barriers related to stigma and varying explanatory models of mental disorders. Sharing tasks with community-based workers in a collaborative stepped-care framework is an approach that is ripe to be scaled up, in particular through integration within national priority health programmes. India and China need to invest in increasing demand for services through active engagement with the community, to strengthen service user leadership and ensure that the content and delivery of mental health programmes are culturally and contextually appropriate.

Pharmacotherapy for post-traumatic stress disorder: systematic review and meta-analysis.

BACKGROUND: Pharmacological treatment is widely used for post-traumatic stress disorder (PTSD) despite questions over its efficacy. AIMS: To determine the efficacy of all types of pharmacotherapy, as monotherapy, in reducing symptoms of PTSD, and to assess acceptability. METHOD: A systematic review and meta-analysis of randomised controlled trials was undertaken; 51 studies were included. RESULTS: Selective serotonin reuptake inhibitors were found to be statistically superior to placebo in reduction of PTSD symptoms but the effect size was small (standardised mean difference -0.23, 95% CI -0.33 to -0.12). For individual pharmacological agents compared with placebo in two or more trials, we found small statistically significant evidence of efficacy for fluoxetine, paroxetine and venlafaxine. CONCLUSIONS: Some drugs have a small positive impact on PTSD symptoms and are acceptable. Fluoxetine, paroxetine and venlafaxine may be considered as potential treatments for the disorder. For most drugs there is inadequate evidence regarding efficacy for PTSD, pointing to the need for more research in this area.

The dopamine receptor D1 gene is associated with the length of interval between first heroin use and onset of dependence in Chinese Han heroin addicts.

Previous researches showed that the dopamine receptor D1 (DRD1) may play a critical role in drug dependence. This research aimed to determine whether DRD1 played a role in development of heroin dependence in Chinese heroin-dependent patients. 465 Chinese Han heroin-dependent subjects and 379 healthy controls were recruited in the Shanghai region. Five single-nucleotide-polymorphisms (SNPs) of the DRD1 gene were genotyped in all subjects. The results found that the frequencies of DRD1 SNP genotypes or haplotypes were not different between heroin-dependent patients and controls. Among heroin-dependent patients, subjects with rs5326CC and/or rs6882300AA genotypes develop to heroin-dependent more rapidly than those without rs5326CC and/or rs6882300AA genotypes. The results indicated that DRD1 gene polymorphism may not play an important role in the susceptibility of heroin dependence in the Chinese Han population, but it may be associated with the rapidity of heroin dependence development from first drug use.

The Monetary Benefits of Reducing Emissions of Dioxin-like Compounds-Century Poisons-Over Half a Century: Evaluation of the Benefit per Ton Method.

The objective of this study is to evaluate the monetary value of health benefits following reductions in century poison dioxin-like compounds for people aged 0-14 years old, 15-64 years old, and persons 65 years or over in Taiwan. The benefit per ton (BPT) method is employed to estimate the monetary value of the benefits of such a reduction from 2021 to 2070 for different age groups in different regions. The results indicate a BPT of US$837,915 per gram of dioxin each year. The results further show that for Taiwan as a whole, the net BPT per gram of dioxin reduction from 2021 to 2025 is US$704 for children, US$42,761 for working-age adults, US$34,817 for older adults, and US$78,282 overall. Reductions in dioxin-like compounds from 2051-2070 will generate 83.93% of the net BPT for the entire country. This is approximately five times the net BPT of emissions reduction from 2021 to 2025. The monetary benefits evaluated in this study indicate that the prevention of health losses caused by the spread and diffusion of dioxin-like compounds have increased significantly. This implies that action must be taken now, along with continued vigilance, to address emission reductions.

A pilot assessment of relapse prevention for heroin addicts in a Chinese rehabilitation center.

OBJECTIVES: To conduct a pilot assessment of relapse prevention (RP) group therapy for heroin-dependent patients in a drug rehabilitation center in China. METHODS: A randomized case-control study was conducted to assess the efficacy of RP delivered over a 2-month period to male heroin addicts (n = 50, RP group) in the Shanghai Labor Drug Rehabilitation Center (LDRC) compared with an equal number of participants (n = 50, labor rehabilitation (LR) group) in the LDRC program receiving standard-of-care treatment. Outcomes were assessed by the Beck Depression Inventory (BDI), the Self-Rating Anxiety Scale (SAS), the Self-Efficacy Scale (SE), and the Self-Esteem Scale (SES) after completion of RP, and by the Addiction Severity Index (ASI) and abstinence rates of heroin use at 3-month follow-up post release from the LDRC for both groups. RESULTS: Significant improvements in scores on SAS, SE, and SES were found in the RP group after completion of the 2-month RP group therapy compared with the LR group (SAS 7.85 ± 6.20 vs 1.07 ± 5.42, SE 3.88 ± 3.60 vs .08 ± 2.89, and SES 3.83 ± 3.31 vs .78 ± 2.55). At 3-month follow-up, the RP group participants had more improvements on ASI scores in most domains and had higher abstinence rates than that in the LR group (37.2% vs 16.7%). CONCLUSIONS: An RP component can be effective in increasing abstinence rates among post-program heroin-dependent individuals and may help reduce anxiety and improve self-esteem and self-efficacy during and following treatment. SCIENTIFIC SIGNIFICANCE: This study suggests RP as a potentially effective component of treatment for heroin addicts.

Association Between the Duration of Untreated Psychosis and Selective Cognitive Performance in Community-Dwelling Individuals With Chronic Untreated Schizophrenia in Rural China.

Importance: Cognitive deficits constitute core features of schizophrenia, but the trajectories of cognitive difficulties in chronic untreated schizophrenia remain unclear. Objective: To assess the association of neuropsychological deficits with duration of untreated psychosis in individuals with chronic untreated schizophrenia. Design, Setting, and Participants: Community-dwelling individuals with chronic untreated schizophrenia (untreated patient group) and individuals without mental illness (control group) were recruited from predominantly rural communities in Ningxia, China between June 20, 2016, and August 6, 2019, and administered the Structured Clinical Interview for DSM-IV, the Mini-Mental State Examination, an 8-test version of the MATRICS Consensus Cognition Battery adapted for use in individuals with low levels of education, and a measure of social cognition. Main Outcomes and Measures: Comparison of cognitive test scores between the two groups and association of cognitive test scores with duration of untreated schizophrenia. Results: The patient group included 197 individuals with chronic untreated schizophrenia (101 men [51.3%]; mean [SD] age, 52.1 [11.8] years; median [interquartile range] years of schooling, 3 [0-6] years; median [interquartile range] years of untreated psychosis, 22.9 [14.9-32.8] years). The control group included 220 individuals (118 men [53.6%]; mean [SD] age, 52.1 [11.2] years; median [interquartile range] years of schooling, 4 [0-6] years). The untreated patient group performed significantly worse than the control group on all cognitive measures (adjusted partial Spearman correlation coefficient [Spearman ρ] ranged from -0.35 for the revised Chinese version of the Reading the Mind in the Eyes Test to -0.60 for the Brief Visuospatial Memory Test-Revised; P < .001 for all comparisons). Longer durations of untreated psychosis were associated with lower performance in 3 MATRICS Consensus Cognition Battery measures assessing different aspects of executive functioning (Brief Visuospatial Memory Test-Revised [ρ = -0.20; P = .04]; Brief Assessment of Cognition in Schizophrenia, Symbol Coding subtest [ρ = -0.35; P < .001]; and Neuropsychological Assessment Battery, Mazes subtest [ρ = -0.24; P = .01]). The median duration of untreated psychosis (22.9 years) was associated with estimated score reductions in the 3 measures of 34% (95% CI, 10%-52%), 43% (95% CI, 28%-55%), and 57% (95% CI, 31%-73%), respectively. Conclusions and Relevance: The findings of this study suggest that long-term untreated schizophrenia was associated with decreases in selective cognitive abilities; both neurodegenerative pathology and neurodevelopmental dysfunction may be factors in cognition in persistent psychosis. Expanding research to include cohorts of patients from underserved rural communities in low- and middle-income countries may provide new insights about the etiological factors, disease course, and management of schizophrenia.

Assessing knowledge and attitudes about mental illness in Ningxia, China.

To assess the effectiveness of China's recent moves to increase community mental health literacy and decrease stigma, we developed the Mental Health Knowledge Questionnaire (MHKQ) and the Mental Health Attitude Questionnaire (MHAQ). Preliminary versions were assessed in pilot studies and revised versions were included in an interviewer-administered community survey of a representative sample of 2425 adult residents of Ningxia Province and a re-test survey in 188 individuals. Internal consistency, factor structure and test-retest reliability were assessed for three measures: (a) the 25-item MHKQ (alpha = .71, 6 factors accounting for 51% of variance identified in exploratory factor analysis of one-half of the sample, and intraclass correlation coefficient [ICC] for total score of .40); (b) the 14-item attitudinal subscale of MHAQ (alpha = .69, 3 factors accounting for 42% of variance, ICC = .47); and (c) the 7-item causal attribution subscale of MHAQ (alpha = .60, 3 factors accounting for 60% of variance, ICC = .26). Confirmatory factor analysis assessed fitness of modified models of the measures using chi-squared, comparative fit index (CFI), Tucker-Lewis index (TLI), and root mean square error of approximation (RMSEA): (a) for the MHKQ, RMSEA = .037 (90% CFI = .033, .040), CFI = .86, TLI = .84, χ2 = 682.86 (df = 260); (b) for the attitudinal subscale of MHAQ, RMSEA = .045 (CI = .039, .052), CFI = .94, TLI = .92, χ2 = 226.67 ( df = 66); and (c) for the causal attribution subscale of MHAQ, RMSEA = .054 (.039, .069), CFI = .97, TLI = .94, χ2 = 49.13 ( df = 11). We conclude that the internal consistency and factor structure of the new measures are satisfactory, but further work is needed to improve the scales' stability and to assess the construct validity and responsiveness of the scales.

Efficacy of Cognitive Behavioral Therapy on Opiate Use and Retention in Methadone Maintenance Treatment in China: A Randomised Trial.

AIMS: Methadone maintenance treatment (MMT) is widely available in China; but, high rates of illicit opiate use and dropout are problematic. The aim of this study was to test whether cognitive behavioral therapy (CBT) in conjunction with MMT can improve treatment retention and reduce opiate use. METHOD: A total of 240 opiate-dependent patients in community-based MMT clinics were randomly assigned to either weekly CBT plus standard MMT (CBT group, n=120) or standard MMT (control group, n=120) for 26 weeks. The primary outcomes were treatment retention and opiate-negative urine test results at 12 weeks and 26 weeks. The secondary outcomes were composite scores on the Addiction Severity Index (ASI) and total scores on the Perceived Stress Scale (PSS) at 12 weeks and 26 weeks. RESULTS: Compared to the control group in standard MMT, the CBT group had higher proportion of opiate-negative urine tests at both 12 weeks (59% vs. 69%, p<0.05) and 26 weeks (63% vs. 73%, p<0.05); however, the retention rates at 12 weeks (73.3% vs. 74.2%, p=0.88) and 26 weeks were not different (55.8% vs. 64.2%, p=0.19) between the two groups. At both 12 and 26 weeks, all of the ASI component scores and PSS total scores in the CBT group and control group decreased from baseline; but the CBT group exhibited more decreases in ASI employment scores at week 26 and more decrease in the PSS total score at week 12 and week 26. CONCLUSIONS: CBT counselling is effective in reducing opiate use and improving employment function and in decreasing stress level for opiate-dependent patients in MMT in China. TRIAL REGISTRATION: ClinicalTrials.gov NCT01144390.

Effects of a Randomized Comprehensive Psychosocial Intervention Based on Cognitive Behavioral Therapy Theory and Motivational Interviewing Techniques for Community Rehabilitation of Patients With Opioid Use Disorders in Shanghai, China.

OBJECTIVES: China is faced with the challenge of community rehabilitation of persons with opioid use disorders. A 1-year comprehensive psychosocial intervention (CPI) was developed, and its effectiveness was assessed in terms of its ability to improve community rehabilitation of persons with opioid use disorders after their release from detention in compulsory treatment centers in Shanghai, China. METHODS: Participants were randomized to the CPI (n = 90) condition or the usual community care (UCC, n = 90) as a control condition. The Addiction Severity Index, Symptom Checklist-90, and Medical Outcomes Study 36-Item Short Form Health Survey were administered at baseline and at the end of the intervention. Urine screens were used to increase the validity of self-reported drug use. RESULTS: Compared with the UCC group at follow-up, the CPI group showed lower scores in 6 dimensions of the Symptom Checklist-90: somatization, obsessive-compulsive, anxiety, phobia-anxiety, paranoia, and psychoticism. Members of the CPI group had higher scores in 2 dimensions of the 36-Item Short Form Health Survey­physical role limitation and emotional role limitation­compared with the UCC group (P < 0.05). A logistic regression analysis revealed that phobia-anxiety, lifetime heroin or amphetamine use, and injection drug use were risk factors of relapse, but differences were not found in drug urine test or self-report drug use between the 2 groups (P > 0.05). CONCLUSIONS: The CPI condition improved participants' mental health and quality of life, and it could be a promising community rehabilitation approach for patients with opioid use disorders in recovery.

Internal consistency and test-retest reliability of the Chinese version of the 5-item Duke University Religion Index.

BACKGROUND: The Duke University Religion Index (DUREL) is a widely-used 5-item scale assessing religiosity. AIM: Assess the internal consistency, reliability, and factor structure of the revised Chinese version of DUREL. METHODS: Using probability proportionate to size (PPS) methods we randomly identified 3981 households with eligible occupants in 20 primary sampling sites in Ningxia Hui Autonomous Region, a province in northwest China in which 34% of the population are Muslims of the Hui ethnic group. In 3054 households a screening interview was completed and an adult family member was randomly selected; 2425 respondents completed the survey (including the DUREL) and 188 randomly selected individuals repeated the survey an average of 2.5 days later. RESULTS: The internal consistency (Cronbach's α) of the 5 items in the full sample was 0.90; it ranged from 0.70 to 0.90 in various subgroups of subjects stratified by ethnicity, urban versus rural residence, and above versus below median education. The test-retest reliability (intraclass correlation coefficient) for the total score in the full sample was 0.87; it ranged from 0.63 to 0.90 in the different subgroups of subjects. Exploratory factor analysis in a random half of the sample identified a single factor (eigen value=4.21) that explained 84% of the total variance. Confirmatory factor analysis in the second half of the sample confirmed the unidimensional model; the model fit measures of the one-factor model using the 5 item scores as observed variables were acceptable (comparative fit index [CFI] and Tucker-Lewis index [TLI]>0.99; root mean square error of approximation [RMSEA]=0.105; χ (2) =70.49, df=5), but the model fit improved after adding the correlation between items 1 and 2 (that assess organized and personal religious activities, respectively) as a sixth observed variable(CFI and TLI>0.99; RMSEA=0.046; χ (2) =14.32, df=4). CONCLUSION: The Chinese version of the DUREL is a reliable and valid measure of religiosity that can be used to assess the relationship of religiosity/spirituality to physical and psychological wellbeing in Chinese respondents. As suggested by other authors, our factor analysis results indicate that the overall score is the best measure derived from the scale, not the three dimensional scores recommended by the original authors.

Cue-induced craving and physiological reactions in recently and long-abstinent heroin-dependent patients.

OBJECTIVE: To understand the different patterns of cue-induced craving and physiological reactions among recently abstinent and long-abstinent heroin-dependent patients. METHOD: 26 healthy adult controls (HC), 29 long-abstinent (more than 1 year, LA), and 26 recently abstinent (less than 1 month, RA) heroin-dependent individuals were exposed to heroin-related and neutral video cues, one video per session, on different days in random order. Self-reported heroin craving by a 10-point visual analog scale (VAS), physiological reactions [skin conductance (SC), muscle electromyography (MEG), skin temperature (TEMP)] and cardiovascular arousal [heart rates (HR), systolic blood pressure (HBP) and diastolic blood pressure (LBP)] were assessed at baseline and after exposure. RESULTS: Both heroin-abstinent groups showed increased heroin craving, SC, MEG, HR, SBP and LBP after exposure to heroin-related video, compared to the control group and compared to exposure to the neutral video. Except the RA group showed more HR changes, changes of heroin craving, SC, MEG, HR, SBP and LBP after exposure to the heroin cue video were not different between the LA and RA groups. CONCLUSIONS: Abstinent heroin-dependent patients had elevated craving and physiological reactions after exposure to videos containing heroin-related cues and the cue induced responses still occurred in long-abstinent patients. This phenomenon should be addressed in treatment and recovery services for heroin dependence.

The Chinese version of the Addiction Severity Index (ASI-C): reliability, validity, and responsiveness in Chinese patients with alcohol dependence.

We evaluated the reliability, validity, and responsiveness of the Chinese version of the 5th edition Addiction Severity Index (ASI-C-5) in Chinese male alcohol-dependent inpatients. Three hundred and fifty-four inpatients with alcohol dependence from five regions of China were interviewed in person by five trained interviewers using the ASI-C-5. Responses were then analyzed for internal consistency reliability, discriminant validity, criterion validity, and responsiveness. Forty subjects were re-interviewed 7 days later to assess test-retest reliability. The ASI-C-5 had good internal consistency, with an overall standardized Cronbach's alpha of 0.79. The Cronbach's alpha values for internal consistency of domain CSs ranged from 0.48 to 0.95, and were above 0.60 for six domains. The 7 day test-retest reliability was acceptable as evidenced by high Pearson correlation coefficients (0.75-0.92, p < 0.01) for 6 of 7 domain CSs. Correlation coefficients between the seven domain CSs ranged from 0.007 to 0.390 (p < 0.05 or 0.01 two-sided), indicating strong discriminant validity. The correlation coefficient between the alcohol dependence composite score of ASI-C-5 and the Alcohol Use Disorders Identification Test (AUDIT) was 0.69 (p < 0.01), indicating good criterion validity. The frequency of extreme scores was low, except for significant floor effects in the "Drugs" and "Legal Status" domains. Collectively, these findings suggest that the ASI-C-5 exhibited strong reliability, validity, and responsiveness in Chinese male alcohol-dependent inpatients.

Pathways to age of onset of heroin use: a structural model approach exploring the relationship of the COMT gene, impulsivity and childhood trauma.

BACKGROUND: The interaction of the association of dopamine genes, impulsivity and childhood trauma with substance abuse remains unclear. OBJECTIVES: To clarify the impacts and the interactions of the Catechol -O-methyltransferase (COMT) gene, impulsivity and childhood trauma on the age of onset of heroin use among heroin dependent patients in China. METHODS: 202 male and 248 female inpatients who meet DSM-IV criteria of heroin dependence were enrolled. Impulsivity and childhood trauma were measured using BIS-11 (Barratt Impulsiveness Scale-11) and ETISR-SF (Early Trauma Inventory Self Report-Short Form). The single nucleotide polymorphism (SNP) rs737866 on the COMT gene-which has previously been associated with heroin abuse, was genotyped using a DNA sequence detection system. Structural equations model was used to assess the interaction paths between these factors and the age of onset of heroin use. PRINCIPAL FINDINGS: Chi-square test indicated the individuals with TT allele have earlier age of onset of heroin use than those with CT or CC allele. In the correlation analysis, the severity of childhood trauma was positively correlated to impulsive score, but both of them were negatively related to the age of onset of heroin use. In structure equation model, both the COMT gene and childhood trauma had impacts on the age of onset of heroin use directly or via impulsive personality. CONCLUSIONS: Our findings indicated that the COMT gene, impulsive personality traits and childhood trauma experience were interacted to impact the age of onset of heroin use, which play a critical role in the development of heroin dependence. The impact of environmental factor was greater than the COMT gene in the development of heroin dependence.

Role of novelty seeking personality traits as mediator of the association between COMT and onset age of drug use in Chinese heroin dependent patients.

BACKGROUND: Personality traits such as novelty seeking (NS) are associated with substance dependence but the mechanism underlying this association remains uncertain. Previous studies have focused on the role of the dopamine pathway. OBJECTIVE: Examine the relationships between allelic variants of the catechol-O-methyltransferase (COMT) gene, NS personality traits, and age of onset of drug use in heroin-dependent subjects in China. METHODS: The 478 heroin dependent subjects from four drug rehabilitation centers in Shanghai who were genotyped for eight tagging single nucleotide polymorphisms (SNP) on the COMT gene completed the NS subscale from the Temperament and Character Inventory. Multivariate analyses were used to assess the potential mediating role of NS personality traits in the association between COMT gene variants and the age of onset of heroin use. PRINCIPAL FINDINGS AND CONCLUSIONS: In the univariate analysis the COMT rs737866 gene variants were independently associated with both NS and age of onset of drug use: those with the TT genotype had higher NS subscale scores and an earlier onset age of heroin use than individuals with CT or CC genotypes. In the multivariate analysis the inclusion of the NS subscore variable weakened the relationship between the COMT rs737866 TT genotype and an earlier age of onset of drug use. Our findings that COMT is associated with both NS personality traits and with the age of onset of heroin use helps to clarify the complex relationship between genetic and psychological factors in the development of substance abuse.

Development, extinction and reinstatement of morphine withdrawal-induced conditioned place aversion in rats.

The motivational component of drug withdrawal may contribute to drug seeking and relapse through the negative reinforcement-based process. Here, we used conditioned place aversion (CPA) induced by naloxone-precipitated morphine withdrawal to measure the aversive effects. Using an unbiased conditioning paradigm, we treated rats with morphine hydrochloride [(10 mg/kg intraperitoneally (i.p.)] twice per day (at 08:00 and 20:00) for 6.5 days (from day 1 to day 7 morning), while gave them naloxone (0.3 mg/kg i.p.) on day 6, a precipitated withdrawal paired with a compartment that caused CPA to the side. Then, the rats exhibited CPA were received 12 extinction trials from days 7 to 13, by daily exposed to the two compartments for free exploration. On day 13, the rats with extinguished CPA were treated with a priming injection of morphine (10 mg/kg i.p.) followed by naloxone (0.3 mg/kg i.p.) that reliably reinstated CPA. These results demonstrated that repeatedly morphine-treated rats showed the formation, extinction and reinstatement of CPA. The present CPA model induced by these procedures may be useful for studying the biological mechanisms underlying the aversive motivational component of opiate withdrawal.