Health outcomes associated with methamphetamine use among young people: a systematic review

Objectives Methamphetamine (MA) use among young people is of significant social, economic and public health concern to affected communities and policy makers. While responses have focused upon various perceived severe harms of MA use, effective public health interventions require a strong scientific evidence base. Methods We conducted a systematic review to identify scientific studies investigating health outcomes associated with MA use among young people aged 10–24 years. The International Classification of Diseases (ICD‐10) was used to categorize outcomes and determine the level of evidence for each series of harms. Results We identified 47 eligible studies for review. Consistent associations were observed between MA use and several mental health outcomes, including depression, suicidal ideation and psychosis. Suicide and overdose appear to be significant sources of morbidity and mortality among young MA users. Evidence for a strong association between MA use and increased risk of human immunodeficiency virus (HIV) and other sexually transmitted infections is equivocal. Finally, we identified only weak evidence of an association between MA use and dental diseases among young people. Conclusions Available evidence indicates a consistent relationship between MA use and mental health outcomes (e.g. depression, psychosis) and an increased risk of mortality due to suicide and overdose. We found insufficient evidence of an association between MA use and other previously cited harms, including infectious diseases and dental outcomes. As such, future research of higher methodological quality is required to further investigate possible associations. Current interventions should focus attention upon MA‐related health outcomes for which sound scientific evidence is available.     

Efficacy and safety of anti‐obesity drugs in children and adolescents: systematic review and meta‐analysis

We undertook a meta‐analysis of randomized controlled trials to summarize the efficacy of anti‐obesity drugs in reducing BMI and improving health in children and adolescents. Data sources included Medline, Embase, the Cochrane controlled trials register and other registers of controlled trials, together with reference lists of identified articles. All data sources were searched from January 1996 to July 2008. We searched for double blind randomized placebo controlled trials of approved anti‐obesity drugs used in children and adolescents (age <20) with primary obesity for ≥6 months. Six trials, 4 of sibutramine (total patients = 686) and 2 of orlistat (n = 573) met inclusion criteria. No trials of rimonabant were identified. Compared with placebo, sibutramine together with behavioural support reduced BMI by 2.20 kg/m² (95% CI: 1.57 to 2.83) and orlistat together with behavioural support reduced BMI by 0.83 kg/m² (95% CI 0.47 to 1.19). Sibutramine improved waist circumference, triglycerides and high density lipoprotein (HDL)‐cholesterol, but raised systolic and diastolic blood pressure and pulse. Orlistat increased rates of gastrointestinal side‐effects. We conclude that sibutramine in adolescents produces clinically meaningful reductions in BMI and waist circumference of approximately 0.63 SD, with improvements in cardiometabolic risk. Orlistat modestly reduces BMI (effect size approximately 0.24 SD) with a high prevalence of gastrointestinal adverse effects.     

Methadone dose and neonatal abstinence syndrome—systematic review and meta‐analysis

Aim To determine if there is a relationship between maternal methadone dose in pregnancy and the diagnosis or medical treatment of neonatal abstinence syndrome (NAS). Methods PubMed, EMBASE, the Cochrane Library and PsychINFO were searched for studies reporting on methadone use in pregnancy and NAS (1966–2009). The relative risk (RR) of NAS was compared for methadone doses above versus below a range of cut‐off points. Summary RRs and 95% confidence intervals (CI) were estimated using random effects meta‐analysis. Sensitivity analyses explored the impact of limiting meta‐analyses to prospective studies or studies using an objective scoring system to diagnose NAS. Results A total of 67 studies met inclusion criteria for the systematic review; 29 were included in the meta‐analysis. Any differences in the incidence of NAS in infants of women on higher compared with lower doses were statistically non‐significant in analyses restricted to prospective studies or to those using an objective scoring system to diagnose NAS. Conclusions Severity of the neonatal abstinence syndrome does not appear to differ according to whether mothers are on high‐ or low‐dose methadone maintenance therapy.     

Intelligence in relation to obesity: a systematic review and meta‐analysis

We performed a systematic review describing obesity/intelligent quotient (IQ) association, particularly childhood IQ in relation to adulthood obesity. After screening 883 citations from five electronic databases, we included 26 studies, most of medium quality. The weighted mean difference (WMD) of the full IQ (FIQ)/obesity association in the pre‐school children was ?15.1 (P > 0.05). Compared with controls, the WMD of FIQ and performance IQ of obese children were ?2.8 and ?10.0, respectively (P < 0.05), and the WMD of verbal IQ was ?7.01 (P > 0.05). With increasing obesity, the FIQ in pre‐school children declined, with a significant difference for severely obese children and FIQ. In pubertal children, a slightly different effect of FIQ and obesity emerged. Two studies reported an inverse FIQ/obesity association in adults, but it was non‐significant after adjusting for educational attainment. Four papers found that childhood FIQ was inversely associated with adult body mass index, but after adjusting for education, became null. Overall there was an inverse FIQ/obesity association, except in pre‐school children. However, after adjusting for educational attainment, FIQ/obesity association was not significantly different. A lower FIQ in childhood was associated with obesity in later adulthood perhaps with educational level mediating the persistence of obesity in later life.     

A systematic review of methamphetamine precursor regulations

Aims To assess the effectiveness of methamphetamine precursor regulations in reducing illicit methamphetamine supply and use. Methods A systematic review of 12 databases was used to identify studies that had evaluated the impact of methamphetamine precursor regulations on methamphetamine supply and/or use. The guidelines of the Effective Practice and Organization of Care Group (EPOC) of The Cochrane Collaboration were used to determine which study designs were included and assess their quality. Results Ten studies met the inclusion criteria. These studies evaluated 15 interventions (13 regulations and two related interdiction efforts), all of which were located in North America. Interventions had consistent impacts across various indicators of methamphetamine supply and use. Seven of the 15 interventions produced reductions in methamphetamine indicators (ranging from 12% to 77%). Two of the largest impacts were seen following interdiction efforts, involving the closure of rogue pharmaceutical companies. There was no evidence of a shift into other types of drug use, or injecting use, although the impact on the synthetic drug market was not examined. Null effects were related largely to the existence of alternative sources of precursor chemicals or the availability of imported methamphetamine. Conclusions Methamphetamine precursor regulations can reduce indicators of methamphetamine supply and use. Further research is needed to determine whether regulations can be effective outside North America, particularly in developing countries, and what impact they have on the broader synthetic drug market. Improved data on precursor diversion are needed to facilitate the evaluation of precursor regulations.