-
Neuroscience and Biobehavioral Reviews Jan 2019Whether the effects of cannabis use on brain function persist or recover following abstinence remains unclear. Therefore, using meta-analytic techniques, we examined... (Meta-Analysis)
Meta-Analysis
Regular cannabis use is associated with altered activation of central executive and default mode networks even after prolonged abstinence in adolescent users: Results from a complementary meta-analysis.
Whether the effects of cannabis use on brain function persist or recover following abstinence remains unclear. Therefore, using meta-analytic techniques, we examined whether functional alterations measured using fMRI persist in cannabis users abstinent for over 25 days (or 600 h) as evidence suggests that the effects on cognitive performance no longer persist beyond this period. Systematic literature search identified 20 studies, of which, 12 examined current cannabis users (CCU) (361 CCU versus 394 non-cannabis using controls (NU)) and 3 examined abstinent cannabis users (ACU) in 5 separate comparisons (98 ACU versus 106 NU). Studies in ACU were carried out in adolescents and suggest significantly greater activation in components of the central executive and default mode networks in adolescent ACU compared to NU. While this evidence is to be interpreted with caution because studies were carried out in overlapping samples, they indicate a pressing need for independent confirmation whether certain neurofunctional alterations in adolescent cannabis users may persist even after cannabis and its metabolites are likely to have left their bodies.
Topics: Adolescent; Brain; Cannabis; Executive Function; Humans; Magnetic Resonance Imaging; Marijuana Abuse; Marijuana Use; Neural Pathways
PubMed: 30395923
DOI: 10.1016/j.neubiorev.2018.10.026 -
Paediatric and Perinatal Epidemiology Nov 2018Normalisation of medicinal and recreational marijuana use has increased the importance of fully understanding effects of marijuana use on individual-and population-level...
BACKGROUND
Normalisation of medicinal and recreational marijuana use has increased the importance of fully understanding effects of marijuana use on individual-and population-level health, including prenatal exposure effects on child development. We undertook a systematic review of the literature to examine the long-term effects of prenatal marijuana exposure on neuropsychological function in children aged 1-11 years.
METHODS
Primary research publications were searched from Medline, Embase, PsychInfo, CINAHL EbscoHost, Cochrane Library, Global Health and ERIC (1980-2018). Eligible articles documented neuropsychological outcomes in children 1-11 years who had been prenatally exposed to marijuana. Studies of exposure to multiple prenatal drugs were included if results for marijuana exposure were reported separately from other substances. Data abstraction was independently performed by two reviewers using a standardised protocol.
RESULTS
The eligible articles (n = 21) on data from seven independent longitudinal studies had high quality based on the Newcastle-Ottawa Scale. Some analyses found associations (P < 0.05) between prenatal marijuana exposure and decreased performance on memory, impulse control, problem-solving, quantitative reasoning, verbal development and visual analysis tests; as well as increased performance on attention and global motion perception tests. Limitations included concurrent use of other substances among study participants, potential under-reporting and publication biases, non-generalisable samples and limited published results preventing direct comparison of analyses.
CONCLUSIONS
The specific effects of prenatal marijuana exposure remain unclear and warrant further research. The larger number of neuropsychological domains that exhibit decreased versus increased psychological and behavioural functions suggests that exposure to marijuana may be harmful for brain development and function.
Topics: Child; Child Behavior; Executive Function; Female; Humans; Marijuana Abuse; Mothers; Neuropsychological Tests; Pregnancy; Prenatal Exposure Delayed Effects
PubMed: 30335203
DOI: 10.1111/ppe.12505 -
Revista Da Associacao Medica Brasileira... May 2018The consumption and abuse of alcohol and other drugs are increasingly present in the lives of university students and may already be considered a public health problem... (Review)
Review
INTRODUCTION
The consumption and abuse of alcohol and other drugs are increasingly present in the lives of university students and may already be considered a public health problem because of the direct impacts on the physical and mental health of these individuals. The requirements of the medical program play a vital role in the increasing rate of drug users.
OBJECTIVES
To carry out a systematic review of the literature on the use of drugs, licit or not, in Brazilian medical students.
METHODS
A descriptive-exploratory study, in which the SciELO and MEDLINE databases were used. A total of 99 articles were found, of which 16 were selected for this review.
RESULTS
Alcohol and tobacco were the most frequently used licit drugs among medical students. The most consumed illicit drugs were marijuana, solvents, "lança-perfume" (ether spray), and anxiolytics. The male genre presented a tendency of consuming more significant amounts of all kinds of drugs, with the exception of tranquilizers. It was found an increasing prevalence of drug consumption in medical students, as the program progressed, which may result from the intrinsic stress from medical school activities. Students who do not use psychoactive drugs are more likely to live with their parents, to disapprove drugs consumption, to practice religious beliefs and to be employed.
CONCLUSION
The prevalence of licit and illicit drug use among medical students is high, even though they understand the injuries it may cause.
Topics: Alcohol Drinking; Brazil; Female; Humans; Illicit Drugs; Male; Marijuana Smoking; Prevalence; Sex Factors; Smoking; Students, Medical; Substance-Related Disorders
PubMed: 30304147
DOI: 10.1590/1806-9282.64.05.462 -
The Cochrane Database of Systematic... Oct 2018Engagement in multiple risk behaviours can have adverse consequences for health during childhood, during adolescence, and later in life, yet little is known about the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Engagement in multiple risk behaviours can have adverse consequences for health during childhood, during adolescence, and later in life, yet little is known about the impact of different types of interventions that target multiple risk behaviours in children and young people, or the differential impact of universal versus targeted approaches. Findings from systematic reviews have been mixed, and effects of these interventions have not been quantitatively estimated.
OBJECTIVES
To examine the effects of interventions implemented up to 18 years of age for the primary or secondary prevention of multiple risk behaviours among young people.
SEARCH METHODS
We searched 11 databases (Australian Education Index; British Education Index; Campbell Library; Cumulative Index to Nursing and Allied Health Literature (CINAHL); Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; Embase; Education Resource Information Center (ERIC); International Bibliography of the Social Sciences; MEDLINE; PsycINFO; and Sociological Abstracts) on three occasions (2012, 2015, and 14 November 2016)). We conducted handsearches of reference lists, contacted experts in the field, conducted citation searches, and searched websites of relevant organisations.
SELECTION CRITERIA
We included randomised controlled trials (RCTs), including cluster RCTs, which aimed to address at least two risk behaviours. Participants were children and young people up to 18 years of age and/or parents, guardians, or carers, as long as the intervention aimed to address involvement in multiple risk behaviours among children and young people up to 18 years of age. However, studies could include outcome data on children > 18 years of age at the time of follow-up. Specifically,we included studies with outcomes collected from those eight to 25 years of age. Further, we included only studies with a combined intervention and follow-up period of six months or longer. We excluded interventions aimed at individuals with clinically diagnosed disorders along with clinical interventions. We categorised interventions according to whether they were conducted at the individual level; the family level; or the school level.
DATA COLLECTION AND ANALYSIS
We identified a total of 34,680 titles, screened 27,691 articles and assessed 424 full-text articles for eligibility. Two or more review authors independently assessed studies for inclusion in the review, extracted data, and assessed risk of bias.We pooled data in meta-analyses using a random-effects (DerSimonian and Laird) model in RevMan 5.3. For each outcome, we included subgroups related to study type (individual, family, or school level, and universal or targeted approach) and examined effectiveness at up to 12 months' follow-up and over the longer term (> 12 months). We assessed the quality and certainty of evidence using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.
MAIN RESULTS
We included in the review a total of 70 eligible studies, of which a substantial proportion were universal school-based studies (n = 28; 40%). Most studies were conducted in the USA (n = 55; 79%). On average, studies aimed to prevent four of the primary behaviours. Behaviours that were most frequently addressed included alcohol use (n = 55), drug use (n = 53), and/or antisocial behaviour (n = 53), followed by tobacco use (n = 42). No studies aimed to prevent self-harm or gambling alongside other behaviours.Evidence suggests that for multiple risk behaviours, universal school-based interventions were beneficial in relation to tobacco use (odds ratio (OR) 0.77, 95% confidence interval (CI) 0.60 to 0.97; n = 9 studies; 15,354 participants) and alcohol use (OR 0.72, 95% CI 0.56 to 0.92; n = 8 studies; 8751 participants; both moderate-quality evidence) compared to a comparator, and that such interventions may be effective in preventing illicit drug use (OR 0.74, 95% CI 0.55 to 1.00; n = 5 studies; 11,058 participants; low-quality evidence) and engagement in any antisocial behaviour (OR 0.81, 95% CI 0.66 to 0.98; n = 13 studies; 20,756 participants; very low-quality evidence) at up to 12 months' follow-up, although there was evidence of moderate to substantial heterogeneity (I² = 49% to 69%). Moderate-quality evidence also showed that multiple risk behaviour universal school-based interventions improved the odds of physical activity (OR 1.32, 95% CI 1.16 to 1.50; I² = 0%; n = 4 studies; 6441 participants). We considered observed effects to be of public health importance when applied at the population level. Evidence was less certain for the effects of such multiple risk behaviour interventions for cannabis use (OR 0.79, 95% CI 0.62 to 1.01; P = 0.06; n = 5 studies; 4140 participants; I² = 0%; moderate-quality evidence), sexual risk behaviours (OR 0.83, 95% CI 0.61 to 1.12; P = 0.22; n = 6 studies; 12,633 participants; I² = 77%; low-quality evidence), and unhealthy diet (OR 0.82, 95% CI 0.64 to 1.06; P = 0.13; n = 3 studies; 6441 participants; I² = 49%; moderate-quality evidence). It is important to note that some evidence supported the positive effects of universal school-level interventions on three or more risk behaviours.For most outcomes of individual- and family-level targeted and universal interventions, moderate- or low-quality evidence suggests little or no effect, although caution is warranted in interpretation because few of these studies were available for comparison (n ≤ 4 studies for each outcome).Seven studies reported adverse effects, which involved evidence suggestive of increased involvement in a risk behaviour among participants receiving the intervention compared to participants given control interventions.We judged the quality of evidence to be moderate or low for most outcomes, primarily owing to concerns around selection, performance, and detection bias and heterogeneity between studies.
AUTHORS' CONCLUSIONS
Available evidence is strongest for universal school-based interventions that target multiple- risk behaviours, demonstrating that they may be effective in preventing engagement in tobacco use, alcohol use, illicit drug use, and antisocial behaviour, and in improving physical activity among young people, but not in preventing other risk behaviours. Results of this review do not provide strong evidence of benefit for family- or individual-level interventions across the risk behaviours studied. However, poor reporting and concerns around the quality of evidence highlight the need for high-quality multiple- risk behaviour intervention studies to further strengthen the evidence base in this field.
Topics: Adolescent; Alcohol Drinking; Automobile Driving; Child; Child, Preschool; Exercise; Family Therapy; Humans; Infant; Marijuana Abuse; Program Evaluation; Randomized Controlled Trials as Topic; Risk-Taking; Schools; Sexual Behavior; Smoking Prevention; Social Behavior Disorders; Substance-Related Disorders; Young Adult
PubMed: 30288738
DOI: 10.1002/14651858.CD009927.pub2 -
Campbell Systematic Reviews 2018This Campbell systematic review examines the effects of recovery schools on student behavioral and academic outcomes, compared to the effects of non-recovery schools....
UNLABELLED
This Campbell systematic review examines the effects of recovery schools on student behavioral and academic outcomes, compared to the effects of non-recovery schools. The review summarizes evidence from one quasi-experimental study (with a total of 194 participants) that had potential serious risk of bias due to confounding. Sizable portions of youth are in recovery from substance use disorders, and many youth will return to use after receiving substance use treatment. Youth spend most of their waking hours at school, and thus schools are important social environments for youth in recovery from substance use disorders. Recovery schools have been identified as educational programs that may help support youth in recovery from substance use disorders. This review focused on two types of recovery schools: RHSs, which are schools that award secondary school diplomas and offer a range of therapeutic services in addition to standard educational curricula; and CRCs, which offer therapeutic and sober support services on college campuses. This review looked at whether recovery schools (RHSs or CRCs) affect academic success and substance use outcomes among students, compared to similar students who are not enrolled in recovery schools.
PLAIN LANGUAGE SUMMARY
Evidence that recovery high schools (RHSs) may improve academic and substance use outcomes is based on the findings from a single study with a serious risk of bias. Very limited evidence addresses the effectiveness of recovery high schools (RHSs). There is no rigorous evidence on the effectiveness of collegiate recovery communities (CRCs).It is unclear whether CRCs are effective in promoting academic success and reducing substance use among college students. This Campbell systematic review examines the effects of recovery schools on student behavioral and academic outcomes, compared to the effects of non-recovery schools. The review summarizes evidence from one quasi-experimental study (with a total of 194 participants) that had potential serious risk of bias due to confounding. Sizable portions of youth are in recovery from substance use disorders, and many youth will return to use after receiving substance use treatment. Youth spend most of their waking hours at school, and thus schools are important social environments for youth in recovery from substance use disorders. Recovery schools have been identified as educational programs that may help support youth in recovery from substance use disorders.This review focused on two types of recovery schools: RHSs, which are schools that award secondary school diplomas and offer a range of therapeutic services in addition to standard educational curricula; and CRCs, which offer therapeutic and sober support services on college campuses.This review looked at whether recovery schools (RHSs or CRCs) affect academic success and substance use outcomes among students, compared to similar students who are not enrolled in recovery schools. The included study of recovery high schools used a controlled quasi-experimental pretest-posttest design and reported on the following outcomes: grade point average, truancy, school absenteeism, alcohol use, marijuana use, other drug use, and abstinence from alcohol/drugs. The included study focused on a sample of U.S. high school students. There were no eligible studies of CRCs. Findings from this review indicate insufficient evidence on the effects of recovery schools on student well-being. Although there is some indication RHSs may improve academic and substance use outcomes, this is based on the findings from a single study. There is no available evidence on the effects of CRCs.No strong conclusions can be drawn at this time, given the lack of available evidence on RHSs and CRCs, and the serious risk of bias in the one RHS study included in the review. The evidence from this review suggests there is a clear need for additional rigorous evaluations of recovery school effects prior to widespread implementation. The review authors searched for studies until September 2018. This Campbell systematic review was published in 2018.
EXECUTIVE SUMMARY/ABSTRACT
Substance use disorders (SUDs) among youth are a major public health problem. In the United States, for example, the incidence of SUDs increases steadily after age 12 and peaks among youth ages 18-23 (White, Evans, Ali, Achara-Abrahams, & King, 2009). Although not every youth who experiments with alcohol or illicit drugs is diagnosed with an SUD, approximately 7-9% of 12-24 year olds in the United States were admitted for public SUD treatment in 2013 (Substance Abuse and Mental Health Services Administration [SAMHSA], 2016). Recovery from an SUD involves reduction or complete abstinence of use, defined broadly as "voluntarily sustained control over substance use, which maximises health and wellbeing and participation in the rights, roles and responsibilities of society" (UK Drug Policy Commission, 2008). However, SUDs are often experienced as chronic conditions; among youth who successfully complete substance use treatment, approximately 45-70% return to substance use within months of treatment discharge (Anderson, Ramo, Schulte, Cummins, & Brown, 2007; Brown, D'Amico, McCarthy, & Tapert, 2001; Ramo, Prince, Roesch, & Brown, 2012; White et al., 2004). Thus, multiple treatment episodes and ongoing recovery supports after treatment are often necessary to assist with the recovery process (Brown et al., 2001; Ramo et al., 2012; White et al., 2004).Success and engagement at school and in postsecondary education are critical to healthy youth development. For youth in recovery from SUDs, school attendance, engagement, and achievement build human capital by motivating personal growth, creating new opportunities and social networks, and increasing life satisfaction and meaning (Keane, 2011; Terrion, 2012; 2014). Upon discharge from formal substance use treatment settings, schools become one of the most important social environments in the lives of youth with SUDs. Healthy school peer environments can enable youth to replace substance use behaviors and norms with healthy activities and prosocial, sober peers. Conversely, many school environments may be risky for youth in recovery from SUDs due to perceived substance use among peers, availability of drugs or alcohol, and substance-approving norms on campus (Centers for Disease Control [CDC], 2011; Spear & Skala, 1995; Wambeam, Canen, Linkenbach, & Otto, 2014).Given the many social and environmental challenges faced by youth in recovery from substance use, recovery-specific institutional supports are increasingly being linked to educational settings. The two primary types of education-based continuing care supports for youth in recovery, defined under the umbrella term of "recovery schools" for this review, are recovery high schools (RHSs) and collegiate recovery communities (CRCs). RHSs are secondary schools that provide standard high school education and award secondary school diplomas, but also include therapeutic programming aimed at promoting recovery (e.g., group check-ins, community service, counseling sessions). CRCs also provide recovery oriented support services (e.g., self-help groups, counseling sessions, sober dorms) for students, but are embedded within larger college or university settings. The primary aims of RHSs and CRCs are to promote abstinence and prevent relapse among students, and thus ultimately improve students' academic success. This review summarized and synthesized the available research evidence on the effects of recovery schools for improving academic success and behavioural outcomes among high school and college students who are in recovery from substance use. The specific research questions that guided the review are as follows: 1. What effect does recovery school attendance (versus attending a non-recovery or traditional school setting) have on academic outcomes for students in recovery from substance use? Specifically (by program type): a. For recovery high schools: what are the effects on measures of academic achievement, high school completion, and college enrolment?b. For collegiate recovery communities: what are the effects on measures of academic achievement and college completion?2. What effect does recovery school attendance have on substance use outcomes for students in recovery from substance use? Specifically, what are the effects on alcohol, marijuana, cocaine, or other substance use?3. Do the effects of recovery schools on students' outcomes vary according to the race/ethnicity, gender, or socioeconomic status of the students?4. Do the effects of recovery schools on students' outcomes vary according to existing mental health comorbidity status or juvenile justice involvement of the students? We aimed to identify all published and unpublished literature on recovery schools by using a comprehensive and systematic literature search. We searched multiple electronic databases, research registers, grey literature sources, and reference lists from prior reviews; and contacted experts in the field. Studies were included in the review if they met the following criteria: Randomized controlled trial (RCT), quasi-randomized controlled trial (QRCT), or controlled quasi-experimental design (QED). Students in recovery from substance use who were enrolled part-time or full-time in secondary (high school) or postsecondary (college or university) educational institutions. Recovery schools broadly defined as educational institutions, or programs at educational institutions, developed specifically for students in recovery and that address recovery needs in addition to academic development.: Traditional educational programs or services that did not explicitly have a substance use recovery focus. The review focused on primary outcomes in the following two domains: academic performance (e.g., achievement test scores, grade-point average, high school completion, school attendance, college enrolment, college completion) and substance use (alcohol, marijuana, cocaine, heroin, stimulant, mixed drug use, or other illicit drug use). Studies that met all other eligibility criteria were considered eligible for the narrative review portion of this review even if they did not report outcomes in one of the primary outcome domains. Studies must have been reported between 1978 and 2016. The search was not restricted by geography, language, publication status, or any other study characteristic. Two reviewers independently screened all titles and abstracts of records identified in the systematic search. Records that were clearly ineligible or irrelevant were excluded at the title/abstract phase; all other records were retrieved in full-text and screened for eligibility by two independent reviewers. Any discrepancies in eligibility assessments were discussed and resolved via consensus. Studies that met the inclusion criteria were coded by two independent reviewers using a structured data extraction form; any disagreements in coding were resolved via discussion and consensus. If members of the review team had conducted any of the primary studies eligible for the review, external and independent data collectors extracted data from those studies. Risk of bias was assessed using the ROBINS-I tool for non-randomized study designs (Sterne, Higgins, & Reeves, 2016).Inverse variance weighted random effects meta-analyses were planned to synthesize effect sizes across studies, as well as heterogeneity analysis, subgroup analysis, sensitivity analysis, and publication bias analysis. However, these synthesis methods were not used given that only one study met the inclusion criteria for the review. Instead, effect sizes (and their corresponding 95% confidence intervals) were reported for all eligible outcomes reported in the study. Only one study met criteria for inclusion in the review. This study used a QED to examine the effects of RHSs on high school students' academic and substance use outcomes. No eligible studies examining CRCs were identified in the search.The results from the one eligible RHS study indicated that after adjusting for pretest values, students in the RHS condition reported levels of grade point averages (= 0.26, 95% CI [-0.04, 0.56]), truancy (= 0.01, 95% CI [-0.29, 0.31]), and alcohol use (= 0.23, 95% CI [-0.07, 0.53]) similar to participants in the comparison condition. However, students in the RHS condition reported improvements in absenteeism (= 0.56, 95% CI [0.25, 0.87]), abstinence from alcohol/drugs ( = 4.36, 95% CI [1.19, 15.98]), marijuana use (= 0.51, 95% CI [0.20, 0.82]), and other drug use (= 0.45, 95% CI [0.14, 0.76]).Overall, there was a serious risk of bias in the one included study. The study had a serious risk of bias due to confounding, low risk of bias due to selection of participants into the study, moderate risk of bias due to classification of interventions, inconclusive risk of bias due to deviations from intended interventions, inconclusive risk of bias due to missing data, moderate risk of bias in measurement of outcomes, and low risk of bias in selection of reported results. There is insufficient evidence regarding the effectiveness of RHSs and CRCs for improving academic and substance use outcomes among students in recovery from SUDs. Only one identified study examined the effectiveness of RHSs. Although the study reported some beneficial effects, the results must be interpreted with caution given the study's potential risk of bias due to confounding and limited external validity. No identified studies examined the effectiveness of CRCs across the outcomes of interest in this review, so it is unclear what effects these programs may have on students' academic and behavioral outcomes.The paucity of evidence on the effectiveness of recovery schools, as documented in this review, thus suggest the need for caution in the widespread adoption of recovery schools for students in recovery from SUDs. Given the lack of empirical support for these recovery schools, additional rigorous evaluation studies are needed to replicate the findings from the one study included in the review. Furthermore, additional research examining the costs of recovery schools may be needed, to help school administrators determine the potential cost-benefits associated with recovery schools.
PubMed: 37131375
DOI: 10.4073/csr.2018.9 -
European Journal of Gastroenterology &... Feb 2019An estimated 22 million adults use marijuana in the USA. The role of marijuana in the progression of hepatic fibrosis remains unclear. (Meta-Analysis)
Meta-Analysis
BACKGROUND
An estimated 22 million adults use marijuana in the USA. The role of marijuana in the progression of hepatic fibrosis remains unclear.
AIMS
We carried out a systematic review and meta-analysis to evaluate the impact of marijuana on prevalence and progression of hepatic fibrosis in chronic liver disease.
PATIENTS AND METHODS
We searched several databases from inception through 10 November 2017 to identify studies evaluating the role of marijuana in chronic liver disease. Our main outcome of interest was prevalence/progression of hepatic fibrosis. Adjusted odds ratios (ORs) and hazards ratios (HRs) were pooled and analyzed using random-effects model.
RESULTS
Nine studies with 5 976 026 patients were included in this meta-analysis. Prevalence of hepatic fibrosis was evaluated in nonalcoholic fatty liver disease (NAFLD), hepatitis C virus (HCV), and hepatitis C and HIV coinfection by two, four, and one studies. Progression of hepatic fibrosis was evaluated by two studies. Pooled OR for prevalence of fibrosis was 0.91 (0.72-1.15), I=75%. On subgroup analysis, pooled OR among NAFLD patients was 0.80 (0.75-0.86), I=0% and pooled OR among HCV patients was 1.96 (0.78-4.92), I=77%. Among studies evaluating HR, pooled HR for progression of fibrosis in HCV-HIV co-infected patients was 1.03 (0.96-1.11), I=0%.
CONCLUSION
Marijuana use did not increase the prevalence or progression of hepatic fibrosis in HCV and HCV-HIV-coinfected patients. On the contrary, we noted a reduction in the prevalence of NAFLD in marijuana users. Future studies are needed to further understand the therapeutic impact of cannabidiol-based formulations in the management of NAFLD.
Topics: Adult; Coinfection; Comorbidity; Disease Progression; Female; HIV Infections; Hepatitis C; Humans; Liver Cirrhosis; Male; Marijuana Abuse; Marijuana Smoking; Middle Aged; Non-alcoholic Fatty Liver Disease; Prevalence; Prognosis; Risk Assessment; Risk Factors; Time Factors
PubMed: 30234644
DOI: 10.1097/MEG.0000000000001263 -
Neuropsychopharmacology : Official... Mar 2019Use of alcohol, cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs. The exact pathophysiology of abuse or... (Meta-Analysis)
Meta-Analysis
Use of alcohol, cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs. The exact pathophysiology of abuse or addiction associated with these sedative substances is not completely understood, but previous research implicates the important role of the striatal dopamine system in the addiction process. Multiple studies investigated changes in the striatal dopamine systems of users of sedative substances, but currently these results are very heterogeneous. Therefore, we conducted a meta-analysis of in vivo neuroimaging studies investigating dopaminergic alterations in the striatum of users of alcohol, opioids or cannabis. Analyses for each substance were conducted separately for the availability of D2/D3 dopamine receptors, dopamine transporters and dopamine synthesis capacity. In total, 723 substance users and 752 healthy controls were included. The results indicated a significant lower striatal D2/D3 receptor availability in alcohol users compared to controls (g = 0.46) but no difference in dopamine transporter availability or dopamine synthesis capacity. Our analysis indicated that changes of dopamine receptors and transporters are moderated by the duration of abstinence. Comparing opioid users with controls revealed a significant lower D2/D3 receptor availability (g = 1.17) and a significantly lower transporter availability (g = 1.55) in opioid users. For cannabis users, there was no significant difference in receptor availability compared to controls and too few studies provided information on dopamine transporter availability or synthesis capacity. Our analysis provides strong evidence for a central role of the striatal dopamine system in use of alcohol or opioids. Further studies are needed to clarify the impact of the dopamine system in cannabis users.
Topics: Alcoholism; Corpus Striatum; Dopamine Plasma Membrane Transport Proteins; Humans; Marijuana Abuse; Neuroimaging; Opioid-Related Disorders; Receptors, Dopamine D2; Receptors, Dopamine D3
PubMed: 30188512
DOI: 10.1038/s41386-018-0191-9 -
BMJ Open Jul 2018We reviewed cohort studies to determine the magnitude and temporal direction of the association between recent intimate partner violence (IPV) and a range of adverse... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
We reviewed cohort studies to determine the magnitude and temporal direction of the association between recent intimate partner violence (IPV) and a range of adverse health outcomes or health risk behaviours.
DESIGN
Systematic review and meta-analysis.
METHODS
Medline, EMBASE and PsycINFO were searched from the first record to November 2016. Recent IPV was defined as occurring up to and including the last 12 months; all health outcomes were eligible for inclusion. Results were combined using random-effects meta-analysis.
RESULTS
35 separate cohort studies were retrieved. Eight studies showed evidence of a positive association between recent IPV and subsequent depressive symptoms, with a pooled OR from five estimates of 1.76 (95% CI 1.26 to 2.44, I=37.5%, p=0.172). Five studies demonstrated a positive, statistically significant relationship between depressive symptoms and subsequent IPV; the pooled OR from two studies was 1.72 (95% CI 1.28 to 2.31, I=0.0%, p=0.752). Recent IPV was also associated with increased symptoms of subsequent postpartum depression in five studies (OR=2.19, 95% CI 1.39 to 3.45, p=0.000), although there was substantial heterogeneity. There was some evidence of a bidirectional relationship between recent IPV and hard drug use and marijuana use, although studies were limited. There was no evidence of an association between recent IPV and alcohol use or sexually transmitted infections (STIs), although there were few studies and inconsistent measurement of alcohol and STIs.
CONCLUSIONS
Exposure to violence has significant impacts. Longitudinal studies are needed to understand the temporal relationship between recent IPV and different health issues, while considering the differential effects of recent versus past exposure to IPV. Improved measurement will enable an understanding of the immediate and longer term health needs of women exposed to IPV. Healthcare providers and IPV organisations should be aware of the bidirectional relationship between recent IPV and depressive symptoms.
PROSPERO REGISTRATION NUMBER
CRD42016033372.
Topics: Alcohol Drinking; Crime Victims; Depression; Depressive Disorder, Major; Female; Humans; Risk Factors; Sex Offenses; Spouse Abuse
PubMed: 30056376
DOI: 10.1136/bmjopen-2017-019995 -
Psychology of Addictive Behaviors :... Aug 2018Reduced motivation is often noted as a consequence of cannabis use. However, prior studies examining this association have suboptimally operationalized motivation and...
Reduced motivation is often noted as a consequence of cannabis use. However, prior studies examining this association have suboptimally operationalized motivation and have yielded mixed findings. This review discusses motivation and the closely related construct of reward sensitivity. We summarize the available literature examining associations between motivation and cannabis use, addressing the following questions: (a) Is there evidence for decreased motivation among cannabis users? (b) Is there evidence that lack of motivation among cannabis users is specific to their use of cannabis (rather than to use of other addictive drugs)? and (c) Is there evidence suggesting a causal relationship between cannabis use and motivation? Using PubMed, PsycINFO, and WebofScience, we conducted a literature search of studies examining nonacute effects of cannabis use on motivation, apathy, amotivation, effort, and reward sensitivity in humans. This search yielded 22 studies, which were reviewed in detail. We conclude that, although cross-sectional evidence of a cannabis-specific effect on motivation is equivocal, there is partial support from longitudinal studies for a causal link between cannabis use and reduced motivation. Additionally, we propose that reward sensitivity and motivation represent distinct yet related constructs and that reductions in one may not always lead to reductions in the other. Future work should longitudinally examine associations between cannabis use, motivation, and reward sensitivity; carefully define and operationalize these constructs; and control for the influence of potential confounding factors. (PsycINFO Database Record
Topics: Cannabis; Cross-Sectional Studies; Humans; Marijuana Abuse; Marijuana Use; Motivation; Reward; Substance-Related Disorders
PubMed: 29963875
DOI: 10.1037/adb0000380 -
Neuron Jun 2018The impaired response inhibition and salience attribution (iRISA) model proposes that impaired response inhibition and salience attribution underlie drug seeking and...
The impaired response inhibition and salience attribution (iRISA) model proposes that impaired response inhibition and salience attribution underlie drug seeking and taking. To update this model, we systematically reviewed 105 task-related neuroimaging studies (n > 15/group) published since 2010. Results demonstrate specific impairments within six large-scale brain networks (reward, habit, salience, executive, memory, and self-directed networks) during drug cue exposure, decision making, inhibitory control, and social-emotional processing. Addicted individuals demonstrated increased recruitment of these networks during drug-related processing but a blunted response during non-drug-related processing, with the same networks also being implicated during resting state. Associations with real-life drug use, relapse, therapeutic interventions, and the relevance to initiation of drug use during adolescence support the clinical relevance of the results. Whereas the salience and executive networks showed impairments throughout the addiction cycle, the reward network was dysregulated at later stages of abuse. Effects were similar in alcohol, cannabis, and stimulant addiction.
Topics: Alcoholism; Amphetamine-Related Disorders; Brain; Cues; Decision Making; Executive Function; Functional Neuroimaging; Humans; Inhibition, Psychological; Marijuana Abuse; Memory; Substance-Related Disorders
PubMed: 29879391
DOI: 10.1016/j.neuron.2018.03.048