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Introduction and Aims: Smoking methamphetamine is associated with increased risk of HIV among female sex workers (FSW). The structural context of substance use is an important shaper of individual behaviour; however, structural determinants of methamphetamine use among FSWs are largely unknown. We identified individual, structural and neighbourhood factors associated with smoking methamphetamine among FSWs in the border city of Tijuana, Baja California, Mexico., Design and Methods: A prospective cohort of 301 FSWs sampled from indoor and outdoor sex work venues throughout Tijuana participated in quantitative surveys on behaviours and mapping of home and work neighbourhoods across three visits. Multinomial logistic regression using generalised estimating equations identified individual, structural and neighbourhood variables associated with smoking methamphetamine., Results: Methamphetamine use, particularly smoking, was highly prevalent among FSWs. Over half (61%) of FSWs had ever used methamphetamine in their lifetime and at baseline, 38% currently smoked methamphetamine. Smoking methamphetamine daily was associated with living in the red light district [adjusted odds ratio (AOR) = 2.72, 95% confidence interval (CI) = 1.23-6.02] and with perceived homelessness, but only among women in a good financial situation (AOR = 4.08, 95% CI = 1.58-10.50). Smoking methamphetamine less than daily was associated with older age (AOR = 1.06, 95% CI = 1.02-1.10)., Discussion and Conclusions: Our findings point to the important dynamic between the residential environment and more severe methamphetamine use. FSWs may prioritise the purchase of methamphetamine over stable housing if they have the financial means. Given the high prevalence of smoking methamphetamine among FSWs in Tijuana, drug treatment options, especially for women living in the red light district, are needed., (© 2017 Australasian Professional Society on Alcohol and other Drugs.)

Repeated administration of psychostimulant drugs, such as amphetamine, induces an enhanced behavioral response to subsequent drug challenge. This behavioral sensitization is proposed to model the increased drug craving observed in human psychostimulant abusers. Current thinking is that the ventral tegmental area, but not the nucleus accumbens, plays a critical role in the development of behavioral sensitization. Here, we report that the concomitant blockade of glutamatergic and nicotinic ionotropic receptors in the core of the nucleus accumbens blocks the development of behavioral sensitization to amphetamine and further abolishes the increase in extracellular dopamine release induced by amphetamine in the nucleus accumbens. These findings demonstrate that the development of behavioral sensitization to amphetamine depends, in addition to the well-known role of the ventral tegmental area, on glutamatergic and nicotinic-dependent mechanisms in the core of the nucleus accumbens and further indicate that the dopaminergic mesolimbic pathway must be viewed as a single coordinated system of critical importance in the development of behavioral sensitization to psychostimulant drugs., (© 2011 The Authors, Addiction Biology © 2011 Society for the Study of Addiction.)

Introduction and Aims: To determine whether recreational methamphetamine use is associated with an increased risk of psychotic symptoms., Design and Method: A cross-sectional survey of 157 people attending dance events in Sydney, Australia. Participants were assessed for psychotic symptoms in the past year using items from the Psychosis Screen. Participants with and without psychotic symptoms were compared on methamphetamine use, polydrug use and other demographic factors. An ordinal logistic regression was used to determine the probability of psychotic symptoms by methamphetamine use and level of polydrug use., Results: Psychotic symptoms in the past year were predicted by methamphetamine use and heavier polydrug use in the past year, and a history of a psychotic disorder (schizophrenia, schizoaffective or bipolar affective disorder). After removing participants with a history of a psychotic disorder (n = 16) and adjusting for polydrug use, methamphetamine use increased the probability of two or more psychotic symptoms (indicative of psychosis risk) from 9% to 21%. There was a non-significant increase in the risk of psychotic symptoms with higher levels of polydrug use. Methamphetamine use was typically monthly or less often (83%), and most users described their use as recreational (85%)., Discussion and Conclusions: Within the context of polydrug use, recreational methamphetamine use is associated with a twofold to threefold increase in the probability of psychotic symptoms.

Aims: To examine whether self-reporting a later stage of pubertal development in early adolescence predicts young adults' use of illicit drugs., Design: Population-based prospective birth cohort study., Setting: Follow-up of a cohort of mothers and their children, recruited between 1981 and 1983., Participants: Cohort of 2710 young adults who completed a self-report questionnaire about their use of cannabis and amphetamines at the 21-year follow-up., Measurements: Young adults' use of cannabis and amphetamines were measured at the 21-year follow-up. Stage of pubertal development was assessed at the 14-year follow-up. Potential confounding and mediating variables were assessed between birth and when the child was 14 years., Findings: Of 2,710 young adults, 49.9% (47.3 females and 52.7% males) reported that they had used cannabis and 21.0% (18.9% females and 23.3% males) reported that they had used amphetamines and cannabis by 21 years. In multivariate analyses, adolescents with a later stage of puberty were more likely to use cannabis or amphetamines in young adulthood. This association was not confounded by mother's education or child's gender and age. Part of the relationship was explained by the higher frequency of child externalizing behaviour at 14 years., Conclusions: The findings warrant further attention to puberty as a sensitive period in an individual's development. With regard to prevention, there is a need to understand more about the pathways between pubertal development, child behaviour problems and substance use.

Several lines of evidence suggest that genetic factors might contribute to drug abuse vulnerability. Recent genomic scans for association demonstrated that the brain-derived neurotrophic factor (BDNF) gene was associated with drug abuse vulnerability. In this study, we analyzed association of two BDNF gene single nucleotide polymorphisms (SNPs), 132C > T (C270T named formerly) in the noncoding region of exon V and 196G > A (val66met) in the coding region of exon XIIIA, with methamphetamine (MAP) abuse in Japan. No significant differences were found in the frequency of the genotype or allele in these two SNPs between MAP abusers and controls (132C > T in exon V: genotype, P = 0.586, allele, P = 0.594; 196G > A (val66met) in exon XIIIA: genotype, P = 0.889, allele, P = 0.713). Furthermore, there was no difference between clinical parameters (e.g., prognosis psychosis, spontaneous relapse, or poly-substance abuse) and the two SNPs of BDNF gene. These results suggest that the two SNPs (132C > T in exon V and 196G > A (val66met) in exon XIIIA) of the BDNF gene may not be associated with Japanese MAP abusers. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299:1/suppmat/index.html., (Copyright 2004 Wiley-Liss, Inc.)

We analyzed two polymorphisms in genes encoding proteins of the dopamine system, the Val158Met polymorphism in the catechol-O-methyltransferase gene and the 120-bp VNTR polymorphism in the promoter of the dopamine D4 receptor gene for association with methamphetamine abuse. We used a case/control design with 416 methamphetamine abusing subjects and 435 normal controls. All subjects were Han Chinese from Taiwan. We found an excess of the high activity Val158 allele in the methamphetamine abuser group, consistent with several previous reports of association of this allele with drug abuse. The 120-bp VNTR polymorphism in the promoter of the dopamine D4 receptor gene itself did not show significant association with methamphetamine abuse. However, analysis of the 120-bp VNTR polymorphism and the exon 3 VNTR in the dopamine D4 receptor as a haplotype showed significant association with methamphetamine abuse, which gave an empirical P value 0.0034 for a heterogeneity model. Moreover, there were significant interactive effects between polymorphisms in the catechol-O-methyltransferase and dopamine D4 genes. The evidence of interaction between COMT 158 Val/Met and DRD4 48-bp VNTR polymorphisms (P = 0.0003, OR = 1.45, 95% CI: 1.148-1.77), and between COMT 158 Val/Met and DRD4 120 bp promoter polymorphisms (P = 0.01, OR = 1.10, 95% CI: 1.10-1.18) were significant but the latter was weak. We conclude that genetic variation in the dopamine system may encode an additive effect on risk of becoming a methamphetamine abuser., (Copyright 2004 Wiley-Liss, Inc.)