Illicit Drug Dependence Research Articles

Drug dependence and prescribing ketamine for treatment-resistant depression in Australia and New Zealand.

Ketamine is a restricted and regulated medication in Australia and New Zealand, which has implications when considering treatment for patients with treatment-resistant depression and a history of illicit drug use, abuse or dependence. Regulations governing prescription of ketamine for treatment-resistant depression vary between jurisdictions in Australia and New Zealand, though most restrict use in those with drug dependence. There is substantial variation in definitions of drug dependence used in each jurisdiction, and between the legal and clinical definitions, with the latter specified in the current International Classification of Diseases, Eleventh Revision and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. This paper reviews the literature assessing the risk of ketamine misuse and dependence in patients with a history of illicit drug use, abuse or dependence and presents recommendations for psychiatrists who prescribe ketamine in such patients with treatment-resistant depression.

Insulin resistance and metabolic syndrome in hepatitis C virus seronegative heroin dependents

Initial studies on impaired glucose-insulin homeostasis in heroin dependents have not defined the impact of concomitant hepatitis C infection (HCV), which has been strongly associated with the development of insulin resistanceand metabolic syndrome (MS). The aim of our study was to evaluate the association of heroin dependence with glucose-insulin homeostasis and MS in heroin dependents with HCV seronegativity. Materials and methods: The study was prospective and cross-sectional, including 160 heroin dependents compared to a control group of 60 participants.MS was diagnosed using International Diabetes Federation criteria. The homeostatic model assessment for insulin resistance (HOMA-IR) and pancreatic β-cell function (HOMA-%B) were used for assessing insulin resistance and β-cell function of pancreas. Results: MS was detected in 9.32% of heroin addicts. Heroin dependents with MS compared to dependents without MS were older, had higher BMI, waist circumference and significantly higher systolic and diastolic blood pressure, increased triglycerides (F=8.233, df=2, p<0.001), apoB (F=8.154, df=2, p=0.001), and reduced HDL-C (F=25.926, df=2, p<0.001) and apoA-I (F=16.406, df=2, p<0.001), significantly increased inuslinemia (F=4.928, df=2, p<0.05), insulin resistance-HOMA-IR (F=4,928, df=2, p<0,05) and insignificantly increased pancreatic β-cell function (194.66 ±224.05) (F=2.461, df=2, p>0.05). Conclusions: Insulin resistance and МS, independent of HCV, was also registered in heroin dependence. Timely recognition will enable more successful treatment of comorbidities and illicit drug dependence.

Outrage and algorithms: Shifting drug-related stigma in a digital world

Illicit drug dependence is one of the most stigmatised health conditions worldwide and the harmful impacts of stigma for people who use drugs are well documented. The use of stigmatising language about drugs in traditional media is also well documented. The increasing use of digital media platforms has revolutionised the way we communicate, and extended the reach of our messages. However, there are issues specific to the ways in which these platforms operate that have the potential to increase drug-related stigma. This paper outlines the importance of language, narrative, and imagery in reducing this stigma. It discusses the challenges digital media platforms present to achieving this goal, including the use of engagement strategies that trigger fear and increase stigma, the potential for amplifying stigmatising messages by using algorithms, and the potential for dissemination of misinformation. Key strategies to frame conversations about drug use are presented including 1) appeal to values of fairness and equity rather than scaring people; 2) avoid correcting misinformation as it strengthens unhelpful stigmatising frames of drug use; and 3) create a new narrative, focusing on the diversity of experiences of people who use drugs.Internationally we are at a critical juncture with respect to drug policy reform, and efforts to reduce drug-related stigma are central to building support for these reforms. The extensive reach of digital media platforms represents an important opportunity to communicate about illicit drug use. The challenge is to do so in a way that minimises stigma. If we are to achieve change, a narrative that puts values, people, health care and equity at the centre of the conversation is critical.

Evaluating Correlations Between Premium Cigar Smoking and Mental Health and Substance Use Dependence Conditions Among U.S. Adults, 2010-2019.

Improved understanding of health conditions associated with premium cigar smoking can inform efforts to reduce cigar use. This paper extends findings commissioned for the National Academies of Science, Engineering, and Medicine report on premium cigars. We pooled 2010-2019 National Survey on Drug Use and Health data to evaluate cross-sectional associations between premium cigar smoking and mental health and substance use conditions among U.S. adults. A series of logistic regression models adjusted for age, sex, race and ethnicity, cigarette smoking, and alcohol consumption compared odds of each condition associated with past-month premium cigar smoking relative to past-month nonpremium cigar smoking, never tobacco use, and current established cigarette smoking. Premium cigar smoking was associated with lower adjusted odds of past month serious psychological distress, past year major depressive episode, and cannabis and illicit drug dependence relative to nonpremium cigar and cigarette smoking; however, higher odds of alcohol and cannabis dependence were observed relative to never tobacco use, and lower odds of alcohol dependence were observed relative to current cigarette smoking but not current nonpremium cigar smoking. We observed considerable variation in both magnitude and direction of associations between premium cigar smoking and mental health and substance use indicators depending on the condition and reference group to which premium cigar smoking was compared. Premium cigar smoking frequently cooccurs with cigarette smoking and alcohol consumption, thus potential health correlates must be considered in appropriate context. We observed considerable variation in direction and magnitude of association depending on the health condition and reference population, as well as potential for reverse causality and residual confounding in this cross-sectional analysis. As the tobacco landscape continues to evolve, rigorous scientific studies that incorporate clear differentiation of cigar type, measures of cumulative use, and temporal data collection are necessary to fully evaluate the health effects of premium cigar smoking and effectively inform Food and Drug Administration regulation.

Preparedness for healthy ageing and polysubstance use in long-term cannabis users: a population-representative longitudinal study

SummaryBackgroundCannabis is often characterised as a young person’s drug. However, people who began consuming cannabis in the 1970s and 1980s are no longer young and some have consumed it for many years. This study tested the preregistered hypothesis that long-term cannabis users show accelerated biological ageing in midlife and poorer health preparedness, financial preparedness, and social preparedness for old age.MethodsIn this longitudinal study, participants comprised a population-representative cohort of 1037 individuals born in Dunedin, New Zealand, between April, 1972, and March, 1973, and followed to age 45 years. Cannabis, tobacco, and alcohol use and dependence were assessed at ages 18 years, 21 years, 26 years, 32 years, 38 years, and 45 years. Biological ageing and health, financial, and social preparedness for old age were assessed at age 45 years. Long-term cannabis users were compared using independent samples t tests with five groups: lifelong cannabis non-users, long-term tobacco users, long-term alcohol users, midlife recreational cannabis users, and cannabis quitters. In addition, regression analyses tested dose–response associations for continuously measured persistence of cannabis dependence from age 18 years to 45 years, with associations adjusted for sex, childhood socioeconomic status, childhood IQ, low childhood self-control, family substance dependence history, and persistence of alcohol, tobacco, and other illicit drug dependence.FindingsOf 997 cohort members still alive at age 45 years, 938 (94%) were assessed at age 45 years. Long-term cannabis users showed statistically significant accelerated biological ageing and were less equipped to manage a range of later-life health, financial, and social demands than non-users. Standardised mean differences between long-term cannabis users and non-users were large: 0·70 (95% CI 0·46 to 0·94; p<0·0001) for biological ageing, −0·72 (−0·96 to −0·49, p<0·0001) for health preparedness, −1·08 (−1·31 to −0·85; p<0·0001) for financial preparedness, and −0·59 (−0·84 to −0·34, p<0·0001) for social preparedness. Long-term cannabis users did not fare better than long-term tobacco or alcohol users. Tests of dose–response associations suggested that cannabis associations could not be explained by the socioeconomic origins, childhood IQ, childhood self-control, and family substance-dependence history of long-term cannabis users. Statistical adjustment for long-term tobacco, alcohol, and other illicit drug dependence suggested that long-term cannabis users’ tendency toward polysubstance dependence accounted for their accelerated biological ageing and poor financial and health preparedness, although not for their poor social preparedness (β −0·10, 95% CI −0·18 to −0·02; p=0·017).InterpretationLong-term cannabis users are underprepared for the demands of old age. Although long-term cannabis use appears detrimental, the greatest challenge to healthy ageing is not use of any specific substance, but rather the long-term polysubstance use that characterises many long-term cannabis users. Substance-use interventions should include practical strategies for improving health and building financial and social capital for healthy longevity.

Could Alcohol Abuse and Dependence on Junk Foods Inducing Obesity and/or Illicit Drug Use Represent Danger to Liver in Young People with Altered Psychological/Relational Spheres or Emotional Problems?

Recent data show that young people, mainly due to the pressure of some risk factors or due to disrupted interpersonal relationships, utilise greater reward value and display greater sensitivity to the reinforcing properties of “pleasurable stimuli”, specifically in those situations in which an enhanced dopamine release is present. Alcoholic beverages, foods rich in sugar and fat, and illicit drug use are pleasurable feelings associated with rewards. Research shows that there is a link between substance abuse and obesity in brain functioning. Still, alcohol excess is central in leading to obesity and obesity-related morbidities, such as hepatic steatosis, mainly when associated with illicit drug dependence and negative eating behaviours in young people. It is ascertained that long-term drinking causes mental damage, similarly to drug abuse, but also affects liver function. Indeed, beyond the pharmacokinetic interactions of alcohol with drugs, occurring in the liver due to the same metabolic enzymes, there are also pharmacodynamic interactions of both substances in the CNS. To complicate matters, an important noxious effect of junk foods consists of inducing obesity and obesity-related NAFLD. In this review, we focus on some key mechanisms underlying the impact of these addictions on the liver, as well as those on the CNS.

Factors Associated with Recovery and Flourishing Mental Health in a National Sample of Canadians with a History of Illicit Drug Dependence

Factors Associated with Recovery and Flourishing Mental Health in a National Sample of Canadians with a History of Illicit Drug Dependence

Oral Sensations among Individuals with Illicit Drug Dependence in Rehabilitation Centers: A Cross-Sectional Study.

Background:In developing countries like India, irrespective of the various government laws and actions, substance abuse is a growing problem. Individuals with illicit drug dependence face social and psychological stigma with considerable health problems. Negligence to oral hygiene and lack of oral health treatments intensifies the sensations experienced by the subjects.Aim:The aim is to determine the patterns of substance abuse and oral health sensations among individuals with illicit drug dependence.Materials and Methods:A cross-sectional study was conducted wherein 213 male individuals with illicit drug dependence history, admitted in rehabilitation centers of Bhubaneswar, formed the study population. Information pertaining to the type and duration of drug dependence along with oral sensations experienced by the individuals during a period of 3 months was obtained by interviewing by the subjects. Chi-square test was done to identify variations in oral sensations produced by different illicit drugs and its relationship with their usage pattern.Results:About 40.8% of dependents reported cannabis intake, thus making it the most commonly consumed drug. About 80.8% of all the subjects reported dryness of the mouth, 47.9% reported sensitivity of teeth and 28.2% suffered from the numbness of their mouth. About 19.7% of the individuals felt like chewing on something, 23% inclined toward grinding, whereas 11.7% experienced pain in the jaw muscles and joint. Sixty percent of substance dependents who smoked drugs had sensitive teeth (P ≤ 0.05). All the oral sensations experienced were significantly more among drug dependents with a history of illicit drug usage for >5years in comparison to others.Conclusion:Substance abuse results in a range of oral sensations. De-addiction programs in India lack oral health-care components. Studies on oral complications related to addiction stresses on the need of oral healthcare at various levels, including education, prevention, and treatment. All these components should be amalgamated into general care services for addicts.

Shining light on darkness: suicidal ideation and suicide attempt among Iranian women who do and do not use drugs

Background Illicit drug use and dependence is a well-established risk factor for self-harm and suicide. The present comparative study aimed to evaluate the prevalence of suicidal ideation and suicide attempt among Iranian women. Methods With a cross-sectional design, a total of 787 Iranian women who reported using illicit drugs and 406 women without drug use history were recruited and invited to answer questions regarding their socio-demographic status, individual health conditions, interpersonal information, e.g. experience of sexual, verbal, or physical violence, illicit drug use, and history of suicidal ideation and suicide attempt. Data were collected through gender-matched interviews. Generalized Linear Models (GLM) with Poisson family and log link function were used to report adjusted prevalence ratios (APR) of the associated factors of the study outcomes. Results The mean age (SD) of women with and without drug use was 34.3 (9.2) and 30.5 (11.0) years, respectively. Prevalence of lifetime history of both suicidal ideation (38.54 vs 19.01%) and suicide attempt (26.25 vs 6.55%) was significantly higher among women reporting drug use compared to those reporting no drug use. The APR of the associated factors ranged from 1.8 to 3.1 and from 3.3 to 4.8 for suicidal ideation and suicide attempt, respectively. Conclusion Women who use drugs are at greater risk of suicidal ideation and suicide attempt compared with their peers who do not use drugs. Although further studies are required to explore possible causal relationships between drug use and suicide among Iranian women, a comprehensive package of care and treatment in addition to predominantly drug-related harm reduction programs may help address such critical health issues among Iranian women who use drugs.

Disparities in illicit drug use and disability status among a nationally representative sample of U.S. college students

BackgroundThe number of students with disabilities attending postsecondary institutions is increasing. However, research on substance use among this population is limited. ObjectiveThis study examined disparities in the prevalence of illicit drug use and drug use disorders among college students with disabilities and their counterparts without disabilities. MethodsData from the 2017 National Survey on Drug Use and Health were analyzed. We estimated prevalence and odds of disability, illicit drug use, and illicit drug dependence or abuse in a subsample of college students (n = 6,189). ResultsA majority of college students reporting a disability had a cognitive limitation. Students with any disability had a higher prevalence of illicit drug use and significantly higher odds of ever use of illicit drugs (AOR = 1.47; 95% CI 1.20–1.79). Compared to their peers with no disabilities, they were more likely to have misused any psychotherapeutic in the past year (AOR = 1.38; 95% CI 1.08–1.76), and had nearly twice the odds of misusing prescription pain relievers in the past month (AOR = 1.97; 95% CI 1.11–3.49). Additionally, students with disabilities had three times the odds of meeting criteria for past-year dependence or abuse of any illicit drug (AOR = 3.01; 95% CI 2.06–4.40). ConclusionThis study documented a higher prevalence of drug use and drug use disorders among college students with disabilities compared to their nondisabled peers. Understanding the risk factors for substance use in this population is critical for developing effective prevention and treatment strategies.

Assessing the European impact of alcohol misuse and illicit drug dependence research: clinical practice guidelines and evidence-base policy

BackgroundDespite alcohol and illicit drug dependence being one of the most common diagnoses in Europe, there is heterogeneity of research evidence used in policy and practice.ObjectiveWe sought to (1) evaluate...

A Family-Based Genome Wide Association Study of Externalizing Behaviors.

Shared genetic factors contribute to the high degree of comorbidity among externalizing problems (e.g. substance use and antisocial behavior). We leverage this common genetic etiology to identify genetic influences externalizing problems in participants from the Collaborative Study on the Genetics of Alcoholism (European ancestry = 7568; African ancestry = 3274). We performed a family-based genome-wide association study (GWAS) on externalizing scores derived from criterion counts of five DSM disorders (alcohol dependence, alcohol abuse, illicit drug dependence, illicit drug abuse, and either antisocial personality disorder or conduct disorder). We meta analyzed these results with a similar measure of externalizing in an independent sample, Spit for Science (combined sample N = 15,112). We did not discover any robust genome-wide significant signals. Polygenic scores derived from the ancestry-specific GWAS summary statistics predicted externalizing problems in an independent European ancestry sample, but not in those of African ancestry. However, these PRS were no longer significant after adjusting for multiple testing. Larger samples with deep phenotyping are necessary for the discovery of SNPs related to externalizing problems.

Predictors of Adolescents' First Episode of Homelessness Following Substance Use Treatment

PurposeA growing body of research has identified correlates (i.e., predictors) of youth homelessness. However, such risk and protective factors have not been identified for youth receiving substance use treatment. Using characteristics collected at treatment intake, the present study sought to identify predictors of youths' first episode of homelessness during the 12 months after substance use treatment entry. MethodsData come from a longitudinal study of adolescents (n = 17,911; aged 12–17 years) receiving substance use treatment throughout the U.S. Participants completed surveys at intake and at 3, 6, and 12 months later. Logistic regression and Lasso machine learning regression were used to predict participants' first episode of homelessness in the 12 months after treatment intake. ResultsAfter excluding adolescents reporting previous experiences of homelessness, 5.0% of adolescents reported their first episode of homelessness over the 12 months after treatment intake. The results from logistic and lasso models were generally consistent. Final models revealed that adolescents who were older, male, reported more victimization experiences, mental health problems, family problems, deviant peer relationships, and substance use problems (more treatment episodes and illicit drug dependence) were more likely to report experiencing homelessness. Hispanic/Latino adolescents were less likely to experience homelessness, compared with white adolescents. ConclusionsThe results point to the important risk and protective factors that can be assessed at treatment entry to identify adolescents at greater risk of experiencing their first episode of homelessness.

Machine Learning and Natural Language Processing for Geolocation-Centric Monitoring and Characterization of Opioid-Related Social Media Chatter

Automatic curation of consumer-generated, opioid-related social media big data may enable real-time monitoring of the opioid epidemic in the United States. To develop and validate an automatic text-processing pipeline for geospatial and temporal analysis of opioid-mentioning social media chatter. This cross-sectional, population-based study was conducted from December 1, 2017, to August 31, 2019, and used more than 3 years of publicly available social media posts on Twitter, dated from January 1, 2012, to October 31, 2015, that were geolocated in Pennsylvania. Opioid-mentioning tweets were extracted using prescription and illicit opioid names, including street names and misspellings. Social media posts (tweets) (n = 9006) were manually categorized into 4 classes, and training and evaluation of several machine learning algorithms were performed. Temporal and geospatial patterns were analyzed with the best-performing classifier on unlabeled data. Pearson and Spearman correlations of county- and substate-level abuse-indicating tweet rates with opioid overdose death rates from the Centers for Disease Control and Prevention WONDER database and with 4 metrics from the National Survey on Drug Use and Health for 3 years were calculated. Classifier performances were measured through microaveraged F1 scores (harmonic mean of precision and recall) or accuracies and 95% CIs. A total of 9006 social media posts were annotated, of which 1748 (19.4%) were related to abuse, 2001 (22.2%) were related to information, 4830 (53.6%) were unrelated, and 427 (4.7%) were not in the English language. Yearly rates of abuse-indicating social media post showed statistically significant correlation with county-level opioid-related overdose death rates (n = 75) for 3 years (Pearson r = 0.451, P < .001; Spearman r = 0.331, P = .004). Abuse-indicating tweet rates showed consistent correlations with 4 NSDUH metrics (n = 13) associated with nonmedical prescription opioid use (Pearson r = 0.683, P = .01; Spearman r = 0.346, P = .25), illicit drug use (Pearson r = 0.850, P < .001; Spearman r = 0.341, P = .25), illicit drug dependence (Pearson r = 0.937, P < .001; Spearman r = 0.495, P = .09), and illicit drug dependence or abuse (Pearson r = 0.935, P < .001; Spearman r = 0.401, P = .17) over the same 3-year period, although the tests lacked power to demonstrate statistical significance. A classification approach involving an ensemble of classifiers produced the best performance in accuracy or microaveraged F1 score (0.726; 95% CI, 0.708-0.743). The correlations obtained in this study suggest that a social media-based approach reliant on supervised machine learning may be suitable for geolocation-centric monitoring of the US opioid epidemic in near real time.

ERRATUM: Genome-wide association study identifies loci associated with liability to alcohol and drug dependence that is associated with variability in reward-related ventral striatum activity in African- and European-Americans.

Genetic influences on alcohol and drug dependence partially overlap, however, specific loci underlying this overlap remain unclear. We conducted a genome-wide association study (GWAS) of a phenotype representing alcohol or illicit drug dependence (ANYDEP) among 7291 European-Americans (EA; 2927 cases) and 3132 African-Americans (AA: 1315 cases) participating in the family-based Collaborative Study on the Genetics of Alcoholism. ANYDEP was heritable (h 2 in EA = 0.60, AA = 0.37). The AA GWAS identified three regions with genome-wide significant (GWS; P < 5E-08) single nucleotide polymorphisms (SNPs) on chromosomes 3 (rs34066662, rs58801820) and 13 (rs75168521, rs78886294), and an insertion-deletion on chromosome 5 (chr5:141988181). No polymorphisms reached GWS in the EA. One GWS region (chromosome 1: rs1890881) emerged from a trans-ancestral meta-analysis (EA + AA) of ANYDEP, and was attributable to alcohol dependence in both samples. Four genes (AA: CRKL, DZIP3, SBK3; EA: P2RX6) and four sets of genes were significantly enriched within biological pathways for hemostasis and signal transduction. GWS signals did not replicate in two independent samples but there was weak evidence for association between rs1890881 and alcohol intake in the UK Biobank. Among 118 AA and 481 EA individuals from the Duke Neurogenetics Study, rs75168521 and rs1890881 genotypes were associated with variability in reward-related ventral striatum activation. This study identified novel loci for substance dependence and provides preliminary evidence that these variants are also associated with individual differences in neural reward reactivity. Gene discovery efforts in non-European samples with distinct patterns of substance use may lead to the identification of novel ancestry-specific genetic markers of risk.

Self-reported Health Diagnoses and Demographic Correlates With Kratom Use: Results From an Online Survey.

To determine whether diagnosed pre-existing health conditions correlate with Kratom demographics and use patterns. A cross-sectional, anonymous US national online survey was conducted among 8049 Kratom users in October, 2016 to obtain demographic, health, and Kratom use pattern information. People who use Kratom to mitigate illicit drug dependence self-reported less pain and better overall health than individuals who used Kratom for acute/chronic pain. Self-reported improvements in pre-existing mental health symptoms (attention deficit and hyperactivity disorder/attention deficit disorder, anxiety, bipolar disorder, post-traumatic stress disorder, and depression) attributed to Kratom use were greater than those related to somatic symptoms (back pain, rheumatoid arthritis, acute pain, chronic pain, fibromyalgia). Demographic variables, including female sex, older age, employment status, and insurance coverage correlated with increased likelihood of Kratom use. Kratom use may serve as a self-treatment strategy for a diverse population of patients with pre-existing health diagnoses. Healthcare providers need to be engaging with patients to address safety concerns and potential limitations of its use in clinical practice for specific health conditions.

Effects of repetitive transcranial magnetic stimulation (rTMS) on craving and substance consumption in patients with substance dependence: a systematic review and meta-analysis.

Repetitive transcranial magnetic stimulation (rTMS) is increasingly used as an intervention for treating substance dependence. We aimed to assess evidence of the anti-craving and consumption-reducing effects of rTMS in patients with alcohol, nicotine and illicit drug dependence. A systematic review and meta-analysis of 26 randomized controlled trials (RCTs) published from January 2000 to October 2018 that investigated the effects of rTMS on craving and substance consumption in patients with nicotine, alcohol and illicit drug dependence (n=748). Craving, measured using self-reported questionnaires or visual analog scale, and substance consumption, measured using self-report substance intake or number of addiction relapse cases, were considered as primary and secondary outcomes, respectively. Substance type, study design and rTMS parameters were used as the independent factors in the meta-regression. Results showed that excitatory rTMS of the left dorsolateral pre-frontal cortex (DLPFC) significantly reduced craving [Hedges' g=-0.62; 95% confidence interval (CI)=-0.89 to -0.35; P<0.0001], compared with sham stimulation. Moreover, meta-regression revealed a significant positive association between the total number of stimulation pulses and effect size among studies using excitatory left DLPFC stimulation (P=0.01). Effects of other rTMS protocols on craving were not significant. However, when examining substance consumption, excitatory rTMS of the left DLPFC and excitatory deep TMS (dTMS) of the bilateral DLPFC and insula revealed significant consumption-reducing effects, compared with sham stimulation. Excitatory repetitive transcranial magnetic stimulation of the dorsolateral pre-frontal cortex appears to have an acute effect on reducing craving and substance consumption in patients with substance dependence. The anti-craving effect may be associated with stimulation dose.

Disparities by Sexual Orientation Persist for Major Depressive Episode and Substance Abuse or Dependence: Findings from a National Probability Study of Adults in the United States.

Purpose: This study updates psychiatric epidemiological research by providing recent prevalence estimates of major depression and alcohol and illicit drug abuse or dependence among sexual minority (SM) adults. Methods: Using the 2015 National Survey on Drug Use and Health, we estimated prevalence differences between SM and heterosexual adults, and within SM subgroups, with logistic regression models. Results: Bisexual adults faced an increased burden across all outcomes compared with other SM adults. Gay males had the highest prevalence of alcohol and illicit drug abuse or dependence. Conclusions: Future research must consider sex differences within SM subgroups for development of targeted interventions.

Genome-wide association study identifies loci associated with liability to alcohol and drug dependence that is associated with variability in reward-related ventral striatum activity in African- and European-Americans.

Genetic influences on alcohol and drug dependence partially overlap, however, specific loci underlying this overlap remain unclear. We conducted a genome-wide association study (GWAS) of a phenotype representing alcohol or illicit drug dependence (ANYDEP) among 7291 European-Americans (EA; 2927 cases) and 3132 African-Americans (AA: 1315 cases) participating in the family-based Collaborative Study on the Genetics of Alcoholism. ANYDEP was heritable (h 2 in EA = 0.60, AA = 0.37). The AA GWAS identified three regions with genome-wide significant (GWS; P < 5E-08) single nucleotide polymorphisms (SNPs) on chromosomes 3 (rs34066662, rs58801820) and 13 (rs75168521, rs78886294), and an insertion-deletion on chromosome 5 (chr5:141988181). No polymorphisms reached GWS in the EA. One GWS region (chromosome 1: rs1890881) emerged from a trans-ancestral meta-analysis (EA + AA) of ANYDEP, and was attributable to alcohol dependence in both samples. Four genes (AA: CRKL, DZIP3, SBK3; EA: P2RX6) and four sets of genes were significantly enriched within biological pathways for hemostasis and signal transduction. GWS signals did not replicate in two independent samples but there was weak evidence for association between rs1890881 and alcohol intake in the UK Biobank. Among 118 AA and 481 EA individuals from the Duke Neurogenetics Study, rs75168521 and rs1890881 genotypes were associated with variability in reward-related ventral striatum activation. This study identified novel loci for substance dependence and provides preliminary evidence that these variants are also associated with individual differences in neural reward reactivity. Gene discovery efforts in non-European samples with distinct patterns of substance use may lead to the identification of novel ancestry-specific genetic markers of risk.

Cross-national patterns of substance use disorder treatment and associations with mental disorder comorbidity in the WHO World Mental Health Surveys.

To examine cross-national patterns of 12-month substance use disorder (SUD) treatment and minimally adequate treatment (MAT), and associations with mental disorder comorbidity. Cross-sectional, representative household surveys. Twenty-seven surveys from 25 countries of the WHO World Mental Health Survey Initiative. A total of 2446 people with past-year DSM-IV SUD diagnoses (alcohol or illicit drug abuse and dependence). Outcomes were SUD treatment, defined as having either received professional treatment or attended a self-help group for substance-related problems in the past 12months, and MAT, defined as having either four or more SUD treatment visits to a health-care professional, six or more visits to a non-health-care professional or being in ongoing treatment at the time of interview. Covariates were mental disorder comorbidity and several socio-economic characteristics. Pooled estimates reflect country sample sizes rather than population sizes. Of respondents with past-year SUD, 11.0% [standard error (SE)=0.8] received past 12-month SUD treatment. SUD treatment was more common among people with comorbid mental disorders than with pure SUDs (18.1%, SE=1.6 versus 6.8%, SE=0.7), as was MAT (84.0%, SE=2.5 versus 68.3%, SE=3.8) and treatment by health-care professionals (88.9%, SE=1.9 versus 78.8%, SE=3.0) among treated SUD cases. Adjusting for socio-economic characteristics, mental disorder comorbidity doubled the odds of SUD treatment [odds ratio (OR)=2.34; 95% confidence interval (CI)=1.71-3.20], MAT among SUD cases (OR=2.75; 95% CI=1.90-3.97) and MAT among treated cases (OR=2.48; 95% CI=1.23-5.02). Patterns were similar within country income groups, although the proportions receiving SUD treatment and MAT were higher in high- than low-/middle-income countries. Few people with past-year substance use disorders receive adequate 12-month substance use disorder treatment, even when comorbid with a mental disorder. This is largely due to the low proportion of people receiving any substance use disorder treatment, as the proportion of patients whose treatment is at least minimally adequate is high.