Ready access to illicit drugs among youth and adult users

Retrospective Cohort Study Examining the Correlates of Reported Lifetime Stimulant Use in Persons Diagnosed With Infectious Syphilis in Alberta, Canada, 2018 to 2019

BACKGROUND

We sought to examine the correlates for stimulant use in persons diagnosed with infectious syphilis during an outbreak in Alberta to help guide public health interventions.

METHODS

Infectious syphilis data were extracted from the Communicable Disease and Outbreak Management database from January 1, 2018, to December 31, 2019. Behavioral, demographic, and lifetime reported stimulant use data were obtained. Descriptive analyses and logistic regression were performed for 3 subpopulations (gay, bisexual, and other men who have sex with men; men who have sex with women; and women).

RESULTS

Of 3627 individuals diagnosed with infectious syphilis, 23.9% (n = 867) cases were not interviewed for substance use and were removed from further analysis. Of the remaining 2759 people, 41.8% (n = 1153) self-reported lifetime stimulant use. Gay, bisexual, and other men who have sex with men reported stimulant use less often than women (24.6% vs. 44.1%; P < 0.0001) and men who have sex with women (24.6% vs. 46.2%; P < 0.0001). Multivariable analyses demonstrated that stimulant use was associated with persons who injected drugs, had correctional involvement, or reported multiple sex partners. Men who have sex with women were more likely to self-report First Nations ethnicity (adjusted odds ratio, 1.76 [95% confidence interval, 1.25-2.49]), and women were more likely to have a concurrent gonorrhea infection (adjusted odds ratio, 1.62 [95% confidence interval, 1.15-2.28]).

CONCLUSIONS

Nearly half of infectious syphilis cases in Alberta reported lifetime nonprescription stimulant use. Infectious syphilis cases with stimulant use were associated with injection drug use, multiple sex partners, and correctional involvement. Our observations highlight the need for integration of sexual health services into programs for people who use substances and those in corrections custody.

Social isolation, residential stability, and opioid use disorder among older Medicare beneficiaries: Metropolitan and non-metropolitan county comparison

Research has shown that the prevalence of opioid use disorder (OUD) may rise substantially as society ages, but this issue receives the least attention in the literature. To address this gap, this study utilizes county-level data from multiple data sources (1) to investigate whether social isolation is associated with OUD prevalence among older Medicare beneficiaries, (2) to examine whether and how residential stability moderates the association between social isolation and OUD prevalence in US counties, and (3) to determine if there are any differences in these associations between metropolitan and non-metropolitan counties. The results show that social isolation is a significant factor for county-level OUD prevalence, regardless of metropolitan status. In addition, counties with high residential stability have low prevalence of OUD among older adults and this association is stronger in metropolitan than in non-metropolitan counties. Nonetheless, high levels of residential stability reinforce the positive relationship between social isolation and OUD prevalence. As a result, when developing policies and interventions aimed at reducing OUD among older adults, place of residence must be taken into account.

Initiation into heroin use among street-involved youth in a Canadian setting: A longitudinal cohort study

BACKGROUND

Emerging evidence suggests that non-medical prescription opioid (NMPO) use may be a risk factor for initiating heroin use; however, pathways from PO to heroin use among youth remain underexplored. We sought to examine the association between NMPO use and heroin initiation.

METHODS

Between September 2005 and June 2017 data were derived from an open prospective cohort of street-involved youth aged 14-28 who use illegal drugs in Vancouver, Canada. The study included 526 youth who had never used non-injection heroin, and 652 youth who had never used injection heroin at baseline. We used Cox proportional hazards regressions to examine the association between NMPO use - in addition to other substance use patterns - and subsequent initiation into non-injection and injection heroin use.

RESULTS

Among those who had never used non-injection heroin at baseline, 133 (25.3%) initiated non-injection heroin use during the study period. Among those who had never injected heroin at baseline, 137 (21.0%) initiated heroin injection during the study period. In multivariable analyses, NMPO use, crack use, and crystal methamphetamine use predicted non-injection heroin initiation (all p < 0.05). In separate multivariable analyses, non-injection heroin and crystal methamphetamine predicted heroin injection initiation (all p < 0.05).

CONCLUSIONS

Among street-involved youth in this setting, NMPO use predicted initiation into non-injection heroin use but not initiation into heroin injection. Interestingly, crack cocaine and crystal methamphetamine use were stronger predictors of heroin initiation than NMPO use was, suggesting that stimulant use may carry greater risks for heroin initiation than NMPO use.

Homelessness and incarceration associated with relapse into stimulant and opioid use among youth who are street-involved in Vancouver, Canada

INTRODUCTION AND AIMS

While much research has sought to identify the factors associated with initiation and cessation of various forms of drug use among vulnerable youth, little is known about relapse into drug use in this population. We sought to characterise relapse into stimulant and opioid use among street-involved youth in Vancouver, Canada.

DESIGN AND METHODS

Data were collected between 2005 and 2017 from the At-Risk Youth Study, a prospective cohort study of street-involved youth who use illicit drugs in Vancouver. Multivariable extended Cox regression was utilised to identify factors associated with relapse into illegal stimulants and/or opioids among youth who had previously ceased using stimulants and/or opioids for 6 months or longer.

RESULTS

Among 246 participants who reported a period of cessation lasting 6 months or longer, 165 (67.1%) relapsed at some point during study follow-up. Youth who were recently incarcerated (adjusted hazard ratio [AHR]: 1.46), homeless (AHR: 1.43), or had a history of daily stimulant use (AHR: 1.48) were significantly more likely to report relapse, while youth of who identified as white (AHR: 0.74) were significantly less likely to report relapse (all P < 0.05).

DISCUSSION AND CONCLUSIONS

Relapse into stimulants and/or opioids was common among youth in our setting, and incarceration, homelessness, and daily stimulant use were found to be positively associated with relapse among youth. Findings suggest that increased access to youth housing supports and alternatives to the criminalisation of drug use may help to reduce the rates of relapse into stimulants and/or opioids in this population.

Unemployment, drugs and attitudes among European youth

This paper studies changes in the patterns of drug consumption and attitudes towards drugs in relation to sky-high (youth) unemployment rates brought about by the Great Recession. Our analysis is based on data for 28 European countries that refer to young people. We find that the consumption of cannabis and 'new substances' is positively related to increasing unemployment rates. An increase of 1% in the regional unemployment rate is associated with an increase of 0.7 percentage points in the ratio of young people who state that they have consumed cannabis at some point in time. Our findings also indicate that higher unemployment may be associated with more young people perceiving that access to drugs has become more difficult, particularly access to ecstasy, cocaine and heroin. According to young Europeans, when the economy worsens, anti-drug policies should focus on the reduction of poverty and unemployment, and not on implementing tougher measures against users.

Development of a brief substance use sensation seeking scale: validation and prediction of injection-related behaviors

Sensation seeking, a personality trait, has been shown to predict engagement in high-risk behaviors. However, little is known regarding the impact of sensation seeking on substance use among street youth. We therefore sought to modify a sensation seeking scale (SSS) for use among this population. Street youth from the Vancouver-based At-Risk Youth Study (n = 226) completed the modified SSS. Exploratory and confirmatory factor analysis (EFA/CFA) were undertaken to establish the scale's dimensionality and internal validity. The association between SSS score and injection-related behaviors was tested using generalized estimating equation analysis. EFA results indicated scale unidimensionality. The comparative fit index (CFI) suggested acceptable fit (CFI = 0.914). In multivariate analysis, sensation seeking was independently associated with injection drug use, crystal methamphetamine use, polysubstance use, and binge drug use (all p < 0.05). Our findings provide preliminary support for the use of the modified SSS among street youth.

Declining incidence of hepatitis C virus infection among people who inject drugs in a Canadian setting, 1996-2012

BACKGROUND

People who inject drugs (PWID) are at high risk of hepatitis C virus (HCV) infection. Trends in HCV incidence and associated risk factors among PWID recruited between 1996 and 2012 in Vancouver, Canada were evaluated.

METHODS

Data were derived from a long-term cohort of PWID in Vancouver. Trends in HCV incidence were evaluated. Factors associated with time to HCV infection were assessed using Cox proportional hazards regression.

RESULTS

Among 2,589, 82% (n = 2,121) were HCV antibody-positive at enrollment. Among 364 HCV antibody-negative participants with recent (last 30 days) injecting at enrollment, 126 HCV seroconversions were observed [Overall HCV incidence density: 8.6 cases/100 person-years (py); 95% confidence interval (95% CI): 7.2, 10.1; HCV incidence density among those with injecting during follow-up: 11.5 cases/100 py; 95% CI 9.7, 13.6]. The overall HCV incidence density declined significantly from 25.0/100 py (95% CI: 20.2, 30.3) in 1996-99, as compared to 6.0/100 py (95% CI: 4.1, 8.5) in 2000-2005, and 3.1/100 py (95% CI: 2.0, 4.8) in 2006-2012. Among those with injecting during follow-up, the overall HCV incidence density declined significantly from 27.9/100 py (95% CI: 22.6, 33.6) in 1996-99, as compared to 7.5/100 py (95% CI: 5.1, 10.6) in 2000-2005, and 4.9/100 py (95% CI: 3.1, 7.4) in 2006-2012. Unstable housing, HIV infection, and injecting of cocaine, heroin and methamphetamine were independently associated with HCV seroconversion.

CONCLUSIONS

HCV incidence has dramatically declined among PWID in this setting. However, improved public health strategies to prevent and treat HCV are urgently required to reduce HCV-associated morbidity and mortality.

Health and social harms associated with crystal methamphetamine use among street-involved youth in a Canadian setting

BACKGROUND AND OBJECTIVES

Despite recent increases in crystal methamphetamine use among high-risk populations such as street-involved youth, few prospective studies have examined the health and social outcomes associated with active crystal methamphetamine use.

METHODS

We enrolled 1,019 street-involved youth in Vancouver, Canada, in a prospective cohort known as the at-risk youth study (ARYS). Participants were assessed semi-annually and a generalized estimating equation (GEE) logistic regression was used to identify factors independently associated with active crystal methamphetamine use.

RESULTS

Among 1,019 participants recruited into ARYS between 2005 and 2012 the median follow up duration was 17 months, 320 (31.4%) participants were female and 454 (44.6%) had previously used crystal methamphetamine at baseline. In adjusted GEE analyses, active crystal methamphetamine use was independently associated with Caucasian ethnicity (adjusted odds ratio [AOR] = 1.37; 95% confidence interval [CI]: 1.04-1.81), homelessness (AOR = 1.34; 95% CI: 1.15-1.56), injection drug use (AOR = 3.40; 95% CI: 2.76-4.19), non-fatal overdose (AOR = 1.46; 95%CI: 1.07-2.00), being a victim of violence (AOR = 1.19; 95% CI: 1.02-1.38), involvement in sex work (AOR = 1.39; 95% CI: 1.03-1.86), and drug dealing (AOR = 1.60; 95% CI: 1.35-1.90).

DISCUSSION AND CONCLUSIONS

Prevalence of crystal methamphetamine use was high in this setting and active use was independently associated with a range of serious health and social harms.

SCIENTIFIC SIGNIFICANCE

Evidence-based strategies to prevent and treat crystal methamphetamine use are urgently needed.

Crystal methamphetamine initiation among street-involved youth

BACKGROUND

Although many settings have recently documented a substantial increase in the use of methamphetamine-type stimulants, recent reviews have underscored the dearth of prospective studies that have examined risk factors associated with the initiation of crystal methamphetamine use.

OBJECTIVES

Our objectives were to examine rates and risk factors for the initiation of crystal methamphetamine use in a cohort of street-involved youth.

METHODS

Street-involved youth in Vancouver, Canada, were enrolled in a prospective cohort known as the At-Risk Youth Study (ARYS). A total of 205 crystal methamphetamine-naïve participants were assessed semi-annually and Cox regression analyses were used to identify factors independently associated with the initiation of crystal methamphetamine use.

RESULTS

Among 205 youth prospectively followed from 2005 to 2012, the incidence density of crystal methamphetamine initiation was 12.2 per 100 person years. In Cox regression analyses, initiation of crystal methamphetamine use was independently associated with previous crack cocaine use (adjusted relative hazard [ARH] = 2.24 [95% CI: 1.20-4.20]) and recent drug dealing (ARH = 1.98 [95% CI: 1.05-3.71]). Those initiating methamphetamine were also more likely to report a recent nonfatal overdose (ARH = 3.63 [95% CI: 1.65-7.98]) and to be male (ARH = 2.12 [95% CI: 1.06-4.25]).

CONCLUSIONS

We identified high rates of crystal methamphetamine initiation among this population. Males those involved in the drug trade, and those who used crack cocaine were more likely to initiate crystal methamphetamine use. Evidence-based strategies to prevent and treat crystal methamphetamine use are urgently needed.

Decreased frontal N-acetylaspartate levels in adolescents concurrently using both methamphetamine and marijuana

INTRODUCTION

The potential neurochemical toxicity associated with methamphetamine (MA) or marijuana (MJ) use on the developing adolescent brain is unclear, particularly with regard to individuals with concomitant use of MA and MJ (MA+MJ). In this study, proton magnetic resonance spectroscopy (MRS) was utilized to measure in vivo brain N-acetylaspartate plus N-acetylaspartyl glutamate (tNAA, an indicator of intact neuronal integrity) levels.

METHODS

Three adolescent groups from Cape Town, South Africa completed MRS scans as well as clinical measures including a drug use history. Subjects included (1) nine MA (age=15.7±1.37), (2) eight MA+MJ (age=16.2±1.16) using adolescents and (3) ten healthy controls (age=16.8±0.62). Single voxel spectra were acquired from midfrontal gray matter using a point-resolved spectroscopy sequence (PRESS). The MRS data were post-processed in the fully automated approach for quantitation of metabolite ratios to phosphocreatine plus creatine (PCr+Cr).

RESULTS

A significant reduction in frontal tNAA/PCr+Cr ratios was seen in the MA+MJ group compared to the healthy controls (p=0.01, by 7.2%) and to the MA group (p=0.04, by 6.9%). Significant relationships were also observed between decreased tNAA/PCr+Cr ratios and drug use history of MA or MJ (total cumulative lifetime dose, age of onset, and duration of MA and MJ exposure) only in the MA+MJ group (all p<0.05).

CONCLUSIONS

These findings suggest that in adolescents, concomitant heavy MA+MJ use may contribute to altered brain metabolites in frontal gray matter. The significant associations between the abnormal tNAA/PCr+Cr ratios and the drug use history suggest that MA+MJ abuse may induce neurotoxicity in a dose-responsive manner in adolescent brain.