Systematic review of prospective studies investigating "remission" from amphetamine, cannabis, cocaine or opioid dependence

Stimulant dependence and stimulant-associated psychosis: clinical characteristics and age of onset in a native American community sample

OBJECTIVES

Native Americans experience some of the highest rates of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) stimulant dependence (SD) of all US ethnic groups. The present report examined the clinical characteristics and age of onset of stimulant use, SD, remission from SD, and stimulant-associated psychosis (SAP) in a Native American community sample.

METHODS

Demographic information, stimulant (methamphetamine or cocaine) use, and lifetime Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) psychiatric disorder diagnoses were assessed in 858 Native Americans. Logistic regression was used to assess the associations of demographic, stimulant use, and psychiatric disorder variables with SD, remission from SD, and SAP. Kaplan-Meier survival analyses were used to assess time from first use to the onset of SD.

RESULTS

The overall rate of SD was 33%, of remission from SD 73%, and of SAP 17%. Stimulant dependence was associated with older age, less current annual household income, fewer lifetime years of education, intravenous stimulant use, and earlier age of first stimulant use. Remission from SD was associated with older age, currently being married, and never having used stimulants intravenously. Attention-deficit/hyperactivity disorder (assessed as a lifetime disorder), increased number of years of daily stimulant use, and intravenous use were independently associated with SAP. Younger age at first use was significantly associated with shorter survival to the onset of SD.

CONCLUSIONS

Stimulant dependence is prevalent in this population and is associated with less income and education and an earlier age at first use. Intravenous stimulant use adds additional risk for SD, nonremission, and psychosis.

Attempts to stop or reduce daily cannabis use: An intensive natural history study

We attempted to replicate and add to our prior study of attempts to stop or reduce cannabis use among daily cannabis users trying to change on their own, by observing a larger sample and adding further clinically relevant outcomes. Daily users (n = 193) who intended to stop or reduce sometime in the next 3 months called an Interactive Voice Response system each morning for 3 months to report on cannabis use, attempts to stop or reduce, withdrawal symptoms, and so forth, on the prior day. This study replicated our prior findings that (a) cannabis users trying to change make many, and often rapid, transitions among use as usual, reduction, and abstinence; (b) reduction attempts are more common than abstinence attempts; (c) quit and reduction attempts are short-lived and few participants achieve long-term abstinence; (d) alcohol and drug use are not greater on abstinence days; and (e) few users seek treatment. Novel findings included (f) a greater number of days of abstinence or intentional reduction predicted a greater decline in cannabis dependence, (g) most users do not prepare before their quit attempt, (h) coping outcomes during abstinence predict increased duration of abstinence, (i) tobacco use is less common on days of abstinence, and (j) withdrawal symptoms occur even with short quit attempts. Replication tests in more generalizable samples and of longer duration are indicated. Further natural history studies are likely to provide information to help improve the content of psychological treatments for cannabis use. (PsycINFO Database Record

A cost-effectiveness analysis of opioid substitution therapy upon prison release in reducing mortality among people with a history of opioid dependence

AIM

Although opioid substitution therapy (OST) immediately after prison release reduces mortality, the cost-effectiveness of treatment has not been examined. Therefore, we undertook a cost-effectiveness analysis of OST treatment upon prison release and the prevention of death in the first 6 months post-release.

DESIGN

Population-based, retrospective data linkage study using records of OST entrants (1985-2010), charges and court appearances (1993-2011), prison episodes (2000-11) and death notifications (1985-2011).

SETTING

New South Wales, Australia.

PARTICIPANTS

A cohort of 16,073 people with a history of opioid dependence released from prison for the first time between 1 January 2000 and 30 June 2011.

INTERVENTION

OST treatment compared to no OST treatment at prison release.

MEASUREMENTS

Mortality and costs (treatment, criminal justice system-court, penalties, prison-and the social costs of crime) were evaluated at 6 months post-release. Analyses included propensity score matching, bootstrapping and regression.

FINDINGS

A total of 13,468 individuals were matched (6734 in each group). Twenty (0.3%) people released onto OST died, compared with 46 people (0.7%) not released onto OST. The final average costs were lower for the group that received OST post-release ($7206 versus $14,356). The incremental cost-effectiveness ratio showed that OST post-release was dominant, incurring lower costs and saving more lives. The probability that OST post-release is cost-effective per life-year saved is 96.7% at a willingness to pay of $500.

CONCLUSION

Opioid substitution treatment (compared with no such treatment), given on release from prison to people with a history of opioid dependence, is cost-effective in reducing mortality in the first 6 months of release.

Natural outcome of cannabis use disorder: a 3-year longitudinal follow-up

AIMS

To assess the prevalence and correlates of remission from cannabis use disorders (CUDs), focusing on the proportion of individuals with CUDs that remit without abstaining from cannabis use.

DESIGN

Three-year longitudinal study.

SETTING

Wave 1 (2001) and wave 2 (2004) of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative sample of US adults aged 18 years and over.

PARTICIPANTS

Our sample included 444 individuals diagnosed with DSM-IV cannabis abuse and/or dependence during the 12 months prior to wave 1 of the NESARC.

MEASUREMENTS

Baseline socio-demographic and clinical correlates were analysed for possible outcomes of CUDs after 3 years: abstinent remission, non-abstinent remission and sustained disorder.

FINDINGS

Approximately two-thirds (67%) of individuals with baseline CUD remitted at follow-up. Approximately 37% of those who remitted were non-abstinent. Remission was associated with Hispanic ethnicity [odds ratio (OR)=2.59; 95% confidence interval (CI)=1.27-4.87], baseline daily or almost daily use of cannabis (OR=1.91; 95% CI=1.15-3.16), baseline use of other drugs (OR=1.63; 95% CI=1.04-2.56) and two or more medical conditions at baseline (OR=8.40; 95% CI=2.67-26.41). Non-abstinent remission was associated with baseline daily or almost daily use of cannabis (OR=1.92; 95% CI=1.05-3.51).

CONCLUSIONS

A substantial level of remission from cannabis use disorders (CUDs), including non-abstinent remission, suggests that the nature of CUDs may be more unstable than reported previously.

Mortality among heroin users and users of other internationally regulated drugs: A 27-year follow-up of users in the Epidemiologic Catchment Area Program household samples

BACKGROUND

In contrast to research on more restricted samples of drug users, epidemiological studies open up a view of death rates and survivorship of those who have tried heroin a few times, with no acceleration toward sustained use patterns often seen in treatment and criminal justice samples. At their best, epidemiological estimates of heroin effects on risk of dying are not subject to serious selection biases faced with more restricted samples.

METHODS

Data are from 7207 adult participants aged 18-48 years in United States Epidemiologic Catchment Area Program field surveys, launched in 1980-1984. US National Death Index (NDI) records through 2007 disclosed 723 deaths. NDI enabled estimation of heroin-associated risk of dying as well as survivorship.

RESULTS

Estimated cumulative mortality for all 18-48 year old participants is 3.9 deaths per 1000 person-years (95% confidence interval, CI=3.7, 4.2), relative to 12.4 deaths per 1000 person-years for heroin users (95% CI=8.7, 17.9). Heroin use, even when non-sustained, predicted a 3-4 fold excess of risk of dying prematurely. Post-estimation record review showed trauma and infections as top-ranked causes of these deaths.

CONCLUSIONS

Drawing strengths from epidemiological sampling, standardized baseline heroin history assessments, and very long-term NDI follow-up, this study of community-dwelling heroin users may help clinicians and public health officials who need facts about heroin when they seek to prevent and control heroin outbreaks. Heroin use, even when sporadic or non-sustained, is predictive of premature death in the US, with expected causes of death such as trauma and infections.

Cessation of injecting drug use: The effects of health service utilisation, drug use and demographic factors

BACKGROUND

Injecting drug use is associated with a range of harms, however cessation of injecting is rare. There is a lack of evidence on factors associated with cessation, notably those related to health services other than drug treatment. We examined the incidence and identified longitudinal correlates of first episode of cessation in a cohort of people who inject drugs (PWID).

METHODS

Using discrete-time survival analysis, we examined correlates of the first episode of cessation (no self-reported injecting drug use in the past 12 months), including the use of health services, socio-demographics and drug-related behaviour in a cohort of PWID recruited between 2008 and 2010.

RESULTS

The cohort of 467 participants contributed 1527 person-years from recruitment to 2014. Under a fifth (17.8%) of people reported cessation of 12 months or more, yielding a cessation rate of 5.4 events per 100 person-years. Younger age (25-29 compared to 30 and above) (adjusted hazard ratio (AHR) 1.79, 95% confidence interval (CI) 1.07-3.00) and male gender (AHR 1.67, 95% CI 2.01-2.76) were positively associated with cessation, while past year use of benzodiazepines (AHR 0.45, 95% CI 0.28-0.72), arrest in the past year (AHR 0.50, 95% CI 0.30-0.83) and low SF-8 physical dimension score (AHR 0.42, 95% CI 0.20-1.88) were negatively associated with cessation. Outpatient service use had the largest effect on cessation (AHR 2.28, 95% CI 0.94-5.48, p=0.067).

CONCLUSIONS

Low rates of cessation emphasise the need for sustained and comprehensive harm reduction services. The relationship between outpatient services and cessation suggests that further research into the use in health services among PWID is warranted.

Mortality among older adults with opioid use disorders in the Veteran's Health Administration, 2000-2011

BACKGROUND

The population of people with opioid use disorders (OUD) is aging. There has been little research on the effects of aging on mortality rates and causes of death in this group. We aimed to compare mortality in older (≥ 50 years of age) adults with OUD to that in younger (<50 years) adults with OUD and older adults with no history of OUD. We also examined risk factors for specific causes of death in older adults with OUD.

METHODS

Using data from the Veteran's Health Administration National Patient Care Database (2000-2011), we compared all-cause and cause-specific mortality rates in older adults with OUD to those in younger adults with OUD and older adults without OUD. We then generated a Cox regression model with specific causes of death treated as competing risks.

RESULTS

Older adults with OUD were more likely to die from any cause than younger adults with OUD. The drug-related mortality rate did not decline with age. HIV-related and liver-related deaths were higher among older OUD compared to same-age peers without OUD. There were very few clinically important predictors of specific causes of death.

CONCLUSION

Considerable drug-related mortality in people with OUD suggests a need for greater access to overdose prevention and opioid substitution therapy across the lifespan. Elevated risk of liver-related death in older adults may be addressed through antiviral therapy for hepatitis C virus infection. There is an urgent need to explore models of care that address the complex health needs of older adults with OUD.

Natural course of cannabis use disorders

BACKGROUND

Despite its importance as a public health concern, relatively little is known about the natural course of cannabis use disorders (CUDs). The primary objective of this research was to provide descriptive data on the onset, recovery and recurrence functions of CUDs during the high-risk periods of adolescence, emerging adulthood and young adulthood based on data from a large prospective community sample.

METHOD

Probands (n = 816) from the Oregon Adolescent Depression Project (OADP) participated in four diagnostic assessments (T1-T4) between the ages of 16 and 30 years, during which current and past CUDs were assessed.

RESULTS

The weighted lifetime prevalence of CUDs was 19.1% with an average onset age of 18.6 years. Although gender was not significantly related to the age of initial CUD onset, men were more likely to be diagnosed with a lifetime CUD. Of those diagnosed with a CUD episode, 81.8% eventually achieved recovery during the study period. Women achieved recovery significantly more quickly than men. The recurrence rate (27.7%) was relatively modest, and most likely to occur within the first 36 months following the offset of the first CUD episode. CUD recurrence was uncommon after 72 months of remission and recovery.

CONCLUSIONS

CUDs are relatively common, affecting about one out of five persons in the OADP sample prior to the age of 30 years. Eventual recovery from index CUD episodes is the norm, although about 30% of those with a CUD exhibit a generally persistent pattern of problematic use extending 7 years or longer.

Three-Year Course of Cannabis Dependence and Prediction of Persistence

AIMS

To examine the course and the predictors of the persistence of cannabis dependence.

METHODS

Through cannabis outlets and chain referral, a prospective enriched community cohort of 207 young adults (aged 18-30) with DSM-IV cannabis dependence at baseline (T0) was formed and followed-up after 1.5 (T1) and 3 (T2) years. The presence of cannabis dependence, cannabis-related problems, functional impairment and treatment was assessed using the Composite International Diagnostic Interview (CIDI 3.0) and the Sheehan Disability Scale (SDS). Predictors of persistence were lifetime cannabis abuse and dependence symptoms, cannabis use characteristics, distant vulnerability factors (e.g. childhood adversity, family history of psychological/substance use problems, impulsivity, mental disorders), and proximal stress factors (recent life events, social support).

RESULTS

Four groups were distinguished: persistent dependent (DDD: 28.0%), stable non-persistent (DNN: 40.6%), late non-persistent (DDN: 17.9%) and recurrent dependent (DND: 13.5%). At T2, persisters (DDD) reported significantly more (heavy) cannabis use and cannabis problems than non-persisters (DNN/DDN/DND). Treatment seeking for cannabis-related problems was rare, even among persisters (15.5%). The number (OR = 1.23 (1.03-1.48)) and type ('role impairment' OR = 2.85 (1.11-7.31), 'use despite problems' OR = 2.34 (1.15-4.76)) of lifetime cannabis abuse/dependence symptoms were the only independent predictors of persistence with a total explained variance of 8.8%.

CONCLUSIONS

Persistence of cannabis dependence in the community is low, difficult to predict, and associated with a negative outcome. The substantial proportion of stable non-persisters suggests that screening and monitoring or low-threshold brief interventions may suffice for many non-treatment-seeking cannabis-dependent people. However, those with many lifetime abuse/dependence symptoms may benefit from more intensive interventions.

Offending, custody and opioid substitution therapy treatment utilisation among opioid-dependent people in contact with the criminal justice system: comparison of Indigenous and non-Indigenous Australians

BACKGROUND

Although Indigenous Australians are over-represented among heroin users, there has been no study examining offending, time in custody, and opioid substitution therapy (OST) treatment utilisation among Indigenous opioid-dependent (including heroin) people at the population level, nor comparing these to non-Indigenous opioid-dependent people. The aims of this study were to compare the nature and types of charges, time in custody and OST treatment utilisation between opioid-dependent Indigenous and non-Indigenous Australians in contact with the criminal justice system.

METHODS

This was a population-based, retrospective data linkage study using records of OST entrants in New South Wales, Australia (1985-2010), court appearances (1993-2011) and custody episodes (2000-2012). Charge rates per 100 person-years were compared between Indigenous and non-Indigenous Australians by sex, age and calendar year. Statistical comparisons were made for variables describing the cumulative time and percentage of follow-up time spent in custody, as well as characteristics of OST initiation and overall OST treatment utilisation.

RESULTS

Of the 34,962 people in the cohort, 6,830 (19.5%) were Indigenous and 28,132 (80.5%) non-Indigenous. Among the 6,830 Indigenous people, 4,615 (67.6%) were male and 2,215 (32.4%) female. The median number of charges per person against Indigenous people (25, IQR 31) was significantly greater than non-Indigenous people (9, IQR 16) (p < 0.001). Overall, Indigenous people were charged with 33.2% of the total number of charges against the cohort and 44.0% of all violent offences. The median percentage of follow-up time that Indigenous males and females spent in custody was twice that of non-Indigenous males (21.7% vs. 10.1%, p < 0.001) and females (6.0% vs. 2.9%, p < 0.001). The percentage of Indigenous people who first commenced OST in prison (30.2%) was three times that of non-Indigenous people (11.2%) (p < 0.001). Indigenous males spent less time in OST compared to non-Indigenous males (median percentage of follow-up time in treatment: 40.5% vs. 43.1%, p < 0.001).

CONCLUSIONS

Compared to non-Indigenous opioid-dependent people, Indigenous opioid-dependent people in contact with the criminal justice system are charged with a greater number of offences, spend longer in custody and commonly initiate OST in prison. Hence, contact with the criminal justice system provides an important opportunity to engage Indigenous people in OST.

Perceived neighborhood safety, recovery capital, and successful outcomes among mothers 10 years after substance abuse treatment

This study examines perceived neighborhood characteristics associated with successful outcome among mothers 10 years after being treated for substance use disorders. Data were obtained from 713 mothers first studied at admission to drug treatment in California in 2000-2002 and followed up in 2009-2011. At follow-up, 53.6% of mothers had a successful outcome (i.e., no use of illicit drugs and not involved with the criminal justice system). Perceived neighborhood safety almost doubled the odds of success. Perceived neighborhood safety interacted with social involvement, decreasing the odds of success among mothers who reported more versus less neighborhood social involvement. Perceived neighborhood climate is associated with long-term outcomes among mothers with substance use disorders independent of individual-level characteristics, underscoring the need for further efforts to understand its interaction with recovery capital in ways that promote and impede health.

Exploring the Concepts of Abstinence and Recovery Through the Experiences of Long-Term Opiate Substitution Clients

BACKGROUND

This study aimed to explore the client experience of long-term opiate substitution treatment (OST).

METHODS

A qualitative grounded theory study set in a U.K. rural community drug treatment service.

RESULTS

Continuous OST enabled stability and a sense of "normality." Participants expressed relief at moving away from previous chaotic lifestyles and freedom from the persistent fear of opiate withdrawal. However, for some, being on a script made them feel withdrawn, lethargic, and unable to fully participate in mainstream society. Intrapersonal barriers (motivation and fear) were perceived as key barriers to abstinence.

CONCLUSIONS

Participants experienced long-term OST as a transition between illicit drug use and recovery. Recovery was seen as a process rather than a fixed goal, confirming that there is a need for services to negotiate individualized recovery goals, spanning harm minimization and abstinence-oriented treatment approaches.

The global epidemiology and burden of opioid dependence: results from the global burden of disease 2010 study

AIMS

To estimate the prevalence and burden of disease attributable to opioid dependence globally, regionally and at country level.

METHODS

Multiple search strategies: (i) peer-reviewed literature searches; (ii) systematic searches of online databases; (iii) internet searches; (iv) consultation and feedback from experts. Culling and data extraction followed protocols. DisMod-MR, the latest version of the generic disease modelling system, a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. Disability weight for opioid dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs). Opioid dependence premature mortality was computed as years of life lost (YLLs) and summed with YLDs to calculate disability-adjusted life years (DALYs).

RESULTS

There were 15.5 million opioid-dependent people globally in 2010 [0.22%, 95% uncertainty interval (UI) = 0.20-0.25%]. Age-standardized prevalence was higher in males (0.30%, 95% UI = 0.27-0.35%) than females (0.14%, 95% UI = 0.12-0.16%), and peaked at 25-29 years. Prevalence was higher than the global pooled prevalence in Australasia (0.46%, 95% UI = 0.41-0.53%), western Europe (0.35%, 95% UI = 0.32-0.39) and North America (0.30%, 95% UI = 0.25-0.36). Opioid dependence was estimated to account for 9.2 million DALYs globally (0.37% of global DALYs) in 2010, a 73% increase on DALYs estimated in 1990. Regions with the highest opioid dependence DALY rates were North America (292.1 per 100,000), eastern Europe (288.4 per 100,000), Australasia (278.6 per 100,000) and southern sub-Saharan Africa (263.5 per 100,000). The contribution of YLLs to opioid dependence burden was particularly high in North America, eastern Europe and southern sub-Saharan Africa.

CONCLUSION

Opioid dependence is a substantial contributor to the global disease burden; its contribution to premature mortality (relative to prevalence) varies geographically, with North America, eastern Europe and southern sub-Saharan Africa most strongly affected.

Influência da família no consumo de crack

Objetivo Dimensionar a contribuição de características de grupos familiares de usuários de crack tanto em situações de consumo quanto na promoção da cessação do uso da substância. Métodos Estudo observacional, transversal, misto, com delineamento quantitativo (estatísticas descritiva e analítica, por regressão de Poisson robusta) e qualitativo (análise temática de conteúdos de entrevistas individuais semiestruturadas). Resultados Foram analisados dados oriundos de entrevistas com 519 usuários de crack, dos quais 48,3% referiram já ter feito uso compartilhado com algum familiar. A relação mais referida para compartilhamento do crack foi a conjugal, indicada por 30,6% dos entrevistados. A estimativa das razões de prevalência do desfecho abstinência na data da entrevista, por regressão de Poisson robusta controlada para fatores de confusão, para usuários de crack que referiram uso compartilhado com irmãos, foi de 0,940 (IC95%: 0,885-0,999; p = 0,045), tendo os que não referiram como referência. Na dimensão qualitativa, 20 entrevistados expuseram livremente modalidades de envolvimento dos familiares com o uso da droga, alguns indicando oposição ao consumo, outros estímulo, ou oferta, além da influência recíproca entre consumo de crack e conflitos familiares ou um ambiente considerado negativo. Além disso, os entrevistados que informaram ter familiares em tratamento em saúde mental tiveram 9% mais probabilidade de estar em uso cessado por 12 semanas ou mais (RP = 1,09; IC95%: 1,03-1,15; p = 0,005). Conclusão Os grupos familiares aparecem não somente como fator de proteção, mas também como importante fator de risco para o uso do crack, e sua inclusão como grupo primário de atendimento se justifica com essas evidências.

Time to relapse following treatment for methamphetamine use: a long-term perspective on patterns and predictors

INTRODUCTION

This paper describes methamphetamine (MA) use patterns, specifically the duration of continuing abstinence ("time to relapse") for periods averaging 5 years post-discharge from treatment for MA use, and the relationship with selected user and treatment characteristics.

METHODS

A sample of 350 treatment admissions from a large county substance use disorder (SUD) treatment system was randomly selected (within gender, race/ethnicity, treatment modality strata). Retrospective self-report data are from natural history interviews (NHI) conducted approximately 3 years after treatment and a follow-up of 2-3 years later. Relapse is defined as any use of MA with time as the number of months of continuous MA abstinence after treatment discharge until relapse. This outcome was constructed from a monthly MA use timeline using NHI data. A Cox model was used to examine time to relapse and predictors.

RESULTS

Sixty-one percent of the sample relapsed to MA use within 1 year after treatment discharge and 14% during years 2-5. Significant protective factors predicting longer time to relapse included having experienced serious MA-related psychiatric/behavioral problems (hazard ratio [HR]=0.75, p=0.027), longer duration of the index treatment episode (HR=0.93, p=0.001), and participating in self-help or other treatment during the post-treatment abstinence period (HR=0.29, p<0.001); risk factors for shorter time to relapse included having a parent with alcohol and/or drug use problems (HR=1.35, p=0.020) and involvement in MA sales (HR=1.48, p=0.002).

CONCLUSIONS

Results contribute a long-term perspective on patterns of MA use following treatment and support a need for early post-treatment and long-term continuing care and relapse-prevention services.

The global epidemiology and burden of psychostimulant dependence: findings from the Global Burden of Disease Study 2010

AIMS

To estimate the global prevalence of cocaine and amphetamine dependence and the burden of disease attributable to these disorders.

METHODS

An epidemiological model was developed using DisMod-MR, a Bayesian meta-regression tool, using epidemiological data (prevalence, incidence, remission and mortality) sourced from a multi-stage systematic review of data. Age, sex and region-specific prevalence was estimated for and multiplied by comorbidity-adjusted disability weightings to estimate years of life lost to disability (YLDs) from these disorders. Years of life lost (YLL) were estimated from cross-national vital registry data. Disability-adjusted life years (DALYs) were estimated by summing YLDs and YLLs in 21 regions, by sex and age, in 1990 and 2010.

RESULTS

In 2010, there were an estimated 24.1 million psychostimulant dependent people: 6.9 million cocaine and 17.2 million amphetamines, equating to a point prevalence of 0.10% (0.09-0.11%) for cocaine, and 0.25% (0.22-0.28%) for amphetamines. There were 37.6 amphetamine dependence DALYs (21.3-59.3) per 100,000 population in 2010 and 15.9 per 100,000 (9.3-25.0) cocaine dependence DALYs. There were clear differences between amphetamines and cocaine in the geographic distribution of crude DALYs. Over half of amphetamine dependence DALYs were in Asian regions (52%), whereas almost half of cocaine dependence DALYs were in the Americas (44%, with 23% in North America High Income).

CONCLUSION

Dependence upon psychostimulants is a substantial contributor to global disease burden; the contribution of cocaine and amphetamines to this burden varies dramatically by geographic region. There is a need to scale up evidence-based interventions to reduce this burden.

Facilitators and barriers in treatment seeking for cannabis dependence

BACKGROUND

Relatively few cannabis dependent people seek treatment and little is known about determinants of treatment seeking.

METHODS

Treatment determinants were compared among 70 DSM-IV cannabis dependent patients and 241 non-treatment seeking DSM-IV cannabis dependent community subjects. In addition, perceived facilitators for treatment seeking were assessed in patients, whereas perceived barriers were assessed in 160/241 cannabis dependent community subjects not prepared to seek treatment (precluders), of whom 63/160 showed an objective treatment need, and 30/241 showed a subjective treatment need.

RESULTS

Compared to non-treatment seekers, patients reported more cannabis use (176.9 versus 82.8 joints monthly), more symptoms of dependence (5.6 versus 4.5), higher perceived lack of social support (70.0% versus 41.1%), more pressure to seek treatment (58.6% versus 21.6%), a more positive attitude to treatment, and more previous treatments. In addition, patients reported more mental health problems (internalising disorders 57.1% versus 24.5%; externalising disorders 52.9% versus 35.3%) and more functional impairments (8.4 versus 4.8 monthly days out of role). Cannabis dependent 'precluders' reported desire for self-reliance (50.0%), preference for informal help (22.5%), and absent treatment need (16.9%) as their main reasons not to seek treatment, whereas cannabis dependent community subjects with a subjective treatment need mainly expressed desire for self-reliance (36.7%), treatment ineffectiveness (16.7%), and avoiding stigma (13.3%).

CONCLUSIONS

Functional impairment, mental health problems and social pressure are important reasons to seek treatment in people with cannabis dependence. Treatment participation might improve if desire for self-reliance and the preference for informal help are considered, and perceived ineffectiveness of treatment and stigmatisation are publicly addressed.

Global burden of disease attributable to illicit drug use and dependence: findings from the Global Burden of Disease Study 2010

BACKGROUND

No systematic attempts have been made to estimate the global and regional prevalence of amphetamine, cannabis, cocaine, and opioid dependence, and quantify their burden. We aimed to assess the prevalence and burden of drug dependence, as measured in years of life lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life years (DALYs).

METHODS

We conducted systematic reviews of the epidemiology of drug dependence, and analysed results with Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) Bayesian meta-regression technique (DisMod-MR) to estimate population-level prevalence of dependence and use. GBD 2010 calculated new disability weights by use of representative community surveys and an internet-based survey. We combined estimates of dependence with disability weights to calculate prevalent YLDs, YLLs, and DALYs, and estimated YLDs, YLLs, and DALYs attributable to drug use as a risk factor for other health outcomes.

FINDINGS

Illicit drug dependence directly accounted for 20·0 million DALYs (95% UI 15·3-25·4 million) in 2010, accounting for 0·8% (0·6-1·0) of global all-cause DALYs. Worldwide, more people were dependent on opioids and amphetamines than other drugs. Opioid dependence was the largest contributor to the direct burden of DALYs (9·2 million, 95% UI 7·1-11·4). The proportion of all-cause DALYs attributed to drug dependence was 20 times higher in some regions than others, with an increased proportion of burden in countries with the highest incomes. Injecting drug use as a risk factor for HIV accounted for 2·1 million DALYs (95% UI 1·1-3·6 million) and as a risk factor for hepatitis C accounted for 502,000 DALYs (286,000-891,000). Suicide as a risk of amphetamine dependence accounted for 854,000 DALYs (291,000-1,791,000), as a risk of opioid dependence for 671,000 DALYs (329,000-1,730,000), and as a risk of cocaine dependence for 324,000 DALYs (109,000-682,000). Countries with the highest rate of burden (>650 DALYs per 100,000 population) included the USA, UK, Russia, and Australia.

INTERPRETATION

Illicit drug use is an important contributor to the global burden of disease. Efficient strategies to reduce disease burden of opioid dependence and injecting drug use, such as delivery of opioid substitution treatment and needle and syringe programmes, are needed to reduce this burden at a population scale.

FUNDING

Australian National Health and Medical Research Council, Australian Government Department of Health and Ageing, Bill & Melinda Gates Foundation.

Global burden of disease attributable to mental and substance use disorders: findings from the Global Burden of Disease Study 2010

BACKGROUND

We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to estimate the burden of disease attributable to mental and substance use disorders in terms of disability-adjusted life years (DALYs), years of life lost to premature mortality (YLLs), and years lived with disability (YLDs).

METHODS

For each of the 20 mental and substance use disorders included in GBD 2010, we systematically reviewed epidemiological data and used a Bayesian meta-regression tool, DisMod-MR, to model prevalence by age, sex, country, region, and year. We obtained disability weights from representative community surveys and an internet-based survey to calculate YLDs. We calculated premature mortality as YLLs from cause of death estimates for 1980-2010 for 20 age groups, both sexes, and 187 countries. We derived DALYs from the sum of YLDs and YLLs. We adjusted burden estimates for comorbidity and present them with 95% uncertainty intervals.

FINDINGS

In 2010, mental and substance use disorders accounted for 183·9 million DALYs (95% UI 153·5 million-216·7 million), or 7·4% (6·2-8·6) of all DALYs worldwide. Such disorders accounted for 8·6 million YLLs (6·5 million-12·1 million; 0·5% [0·4-0·7] of all YLLs) and 175·3 million YLDs (144·5 million-207·8 million; 22·9% [18·6-27·2] of all YLDs). Mental and substance use disorders were the leading cause of YLDs worldwide. Depressive disorders accounted for 40·5% (31·7-49·2) of DALYs caused by mental and substance use disorders, with anxiety disorders accounting for 14·6% (11·2-18·4), illicit drug use disorders for 10·9% (8·9-13·2), alcohol use disorders for 9·6% (7·7-11·8), schizophrenia for 7·4% (5·0-9·8), bipolar disorder for 7·0% (4·4-10·3), pervasive developmental disorders for 4·2% (3·2-5·3), childhood behavioural disorders for 3·4% (2·2-4·7), and eating disorders for 1·2% (0·9-1·5). DALYs varied by age and sex, with the highest proportion of total DALYs occurring in people aged 10-29 years. The burden of mental and substance use disorders increased by 37·6% between 1990 and 2010, which for most disorders was driven by population growth and ageing.

INTERPRETATION

Despite the apparently small contribution of YLLs--with deaths in people with mental disorders coded to the physical cause of death and suicide coded to the category of injuries under self-harm--our findings show the striking and growing challenge that these disorders pose for health systems in developed and developing regions. In view of the magnitude of their contribution, improvement in population health is only possible if countries make the prevention and treatment of mental and substance use disorders a public health priority.

FUNDING

Queensland Department of Health, National Health and Medical Research Council of Australia, National Drug and Alcohol Research Centre-University of New South Wales, Bill & Melinda Gates Foundation, University of Toronto, Technische Universität, Ontario Ministry of Health and Long Term Care, and the US National Institute of Alcohol Abuse and Alcoholism.

Remission from substance dependence: differences between individuals in a general population longitudinal survey who do and do not seek help

BACKGROUND

Only a minority of individuals who have substance use disorders receives treatment, and those who do typically have more severe disorders. The current study examines the relationship of help-seeking with remission from alcohol and/or drug dependence and other outcomes.

METHODS

Data from the Wave 1 (2001-2002) and Wave 2 (2004-2005) National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) were used to examine remission at Wave 2 among respondents who had past-year substance dependence disorders at Wave 1 (N=1262). Multi-group structural equation modeling was used to compare individuals with (n=356) and without (n=906) prior help-seeking at Wave 1 on subsequent help-seeking and other factors that influence outcomes.

RESULTS

Baseline help-seekers sought help at higher levels over the follow-up period (31% vs. 8%) and had lower rates of remission (50% vs. 68%), as compared with those without prior help-seeking, respectively. Among baseline help-seekers, there were stronger relationships between baseline stress and mental disorders and having sought help since baseline; age and past-year level of stress at follow-up; level of stress and health status at follow-up; and social support and mental disorders at follow-up. Among baseline non-help-seekers, there were stronger relationships between being female and past-year stress at follow-up, and between having sought help since baseline and physical health status at follow-up.

CONCLUSIONS

Findings extend our understanding of the factors associated with recovery from substance dependence, including "natural recovery", use of services outside of addiction treatment, and gender differences in help-seeking and remission.

The global epidemiology and contribution of cannabis use and dependence to the global burden of disease: results from the GBD 2010 study

AIMS

Estimate the prevalence of cannabis dependence and its contribution to the global burden of disease.

METHODS

Systematic reviews of epidemiological data on cannabis dependence (1990-2008) were conducted in line with PRISMA and meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Culling and data extraction followed protocols, with cross-checking and consistency checks. DisMod-MR, the latest version of generic disease modelling system, redesigned as a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. The disability weight associated with cannabis dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs) and disability-adjusted life years (DALYs). YLDs and DALYs attributed to regular cannabis use as a risk factor for schizophrenia were also estimated.

RESULTS

There were an estimated 13.1 million cannabis dependent people globally in 2010 (point prevalence0.19% (95% uncertainty: 0.17-0.21%)). Prevalence peaked between 20-24 yrs, was higher in males (0.23% (0.2-0.27%)) than females (0.14% (0.12-0.16%)) and in high income regions. Cannabis dependence accounted for 2 million DALYs globally (0.08%; 0.05-0.12%) in 2010; a 22% increase in crude DALYs since 1990 largely due to population growth. Countries with statistically higher age-standardised DALY rates included the United States, Canada, Australia, New Zealand and Western European countries such as the United Kingdom; those with lower DALY rates were from Sub-Saharan Africa-West and Latin America. Regular cannabis use as a risk factor for schizophrenia accounted for an estimated 7,000 DALYs globally.

CONCLUSION

Cannabis dependence is a disorder primarily experienced by young adults, especially in higher income countries. It has not been shown to increase mortality as opioid and other forms of illicit drug dependence do. Our estimates suggest that cannabis use as a risk factor for schizophrenia is not a major contributor to population-level disease burden.

Probability and predictors of cannabis use disorders relapse: results of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

BACKGROUND

This study aims to estimate the odds and predictors of Cannabis Use Disorders (CUD) relapse among individuals in remission.

METHODS

Analyses were done on the subsample of individuals with lifetime history of a CUD (abuse or dependence) who were in full remission at baseline (Wave 1) of the National Epidemiological Survey of Alcohol and Related Conditions (NESARC) (n=2350). Univariate logistic regression models and hierarchical logistic regression model were implemented to estimate odds of relapse and identify predictors of relapse at 3 years follow up (Wave 2).

RESULTS

The relapse rate of CUD was 6.63% over an average of 3.6 year follow-up period. In the multivariable model, the odds of relapse were inversely related to time in remission, whereas having a history of conduct disorder or a major depressive disorder after Wave 1 increased the risk of relapse.

CONCLUSIONS

Our findings suggest that maintenance of remission is the most common outcome for individuals in remission from a CUD. Treatment approaches may improve rates of sustained remission of individuals with CUD and conduct disorder or major depressive disorder.

Estimating remission from untreated major depression: a systematic review and meta-analysis

BACKGROUND

Few studies have examined spontaneous remission from major depression. This study investigated the proportion of prevalent cases of untreated major depression that will remit without treatment in a year, and whether remission rates vary by disorder severity.

METHOD

Wait-list controlled trials and observational cohort studies published up to 2010 with data describing remission from untreated depression at ≤ 2-year follow-up were identified. Remission was defined as rescinded diagnoses or below threshold scores on standardized symptom measures. Nineteen studies were included in a regression model predicting the probability of 12-month remission from untreated depression, using logit transformed remission proportion as the dependent variable. Covariates included age, gender, study type and diagnostic measure.

RESULTS

Wait-listed compared to primary-care samples, studies with longer follow-up duration and older adult compared to adult samples were associated with lower probability of remission. Child and adolescent samples were associated with higher probability of remission. Based on adult samples recruited from primary-care settings, the model estimated that 23% of prevalent cases of untreated depression will remit within 3 months, 32% within 6 months and 53% within 12 months.

CONCLUSIONS

It is undesirable to expect 100% treatment coverage for depression, given many will remit before access to services is feasible. Data were drawn from consenting wait-list and primary-care samples, which potentially over-represented mild-to-moderate cases of depression. Considering reported rates of spontaneous remission, a short untreated period seems defensible for this subpopulation, where judged appropriate by the clinician. Conclusions may not apply to individuals with more severe depression.

Risky sex in rural America: longitudinal changes in a community-based cohort of methamphetamine and cocaine users

BACKGROUND AND OBJECTIVES

This study examined the longitudinal associations between stimulant use and sexual behaviors.

METHODS

Data are from a 3-year community-based study of 710 rural stimulant users. Past 30-day crack cocaine, powder cocaine, and methamphetamine use and sexual behaviors (any sex, inconsistent condom use, and multiple sexual partners) were assessed through in-person interviews every 6 months.

RESULTS

GEE analyses revealed that the odds of having sex remained steady over time, with crack cocaine and methamphetamine use positively associated with having sex. The odds of multiple sexual partners declined, but the odds of inconsistent condom use remained steady over time. Crack cocaine use was positively associated with multiple sexual partners, whereas powder cocaine use was negatively associated with inconsistent condom use.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Many rural stimulant users could potentially benefit from safe sex educational programs. Such efforts could reduce the incidence of HIV and other STIs in rural America.

Extent of illicit drug use and dependence, and their contribution to the global burden of disease

This paper summarises data for the prevalence, correlates, and probable adverse health consequences of problem use of amphetamines, cannabis, cocaine, and opioids. We discuss findings from systematic reviews of the prevalence of illicit drug use and dependence, remission from dependence, and mortality in illicit drug users, and evidence for acute and chronic effects of illicit drug use. We outline the regional and global distribution of use and estimated health burden from illicit drugs. These distributions are likely to be underestimates because they have not included all adverse outcomes of drug use and exclude those of cannabis--the mostly widely used illicit drug. In high-income countries, illicit drug use contributes less to the burden of disease than does tobacco but a substantial proportion of that due to alcohol. The major adverse health effects of cannabis use are dependence and probably psychotic disorders and other mental disorders. The health-related harms of cannabis use differ from those of amphetamine, cocaine, and opioid use, in that cannabis contributes little to mortality. Intelligent policy responses to drug problems need better data for the prevalence of different types of illicit drug use and the harms that their use causes globally. This need is especially urgent in high-income countries with substantial rates of illicit drug use and in low-income and middle-income countries close to illicit drug production areas.

30-year trajectories of heroin and other drug use among men and women sampled from methadone treatment in California

BACKGROUND

This study examines 30-year trajectories of heroin and other drug use among men and women who were in methadone maintenance treatment in California in the late 1970s and interviewed in 1978-1981.

METHODS

Nearly half (N=428; 46.8%) of the original study sample (N=914) was deceased. Of the remaining 486 subjects, 343 (44.3% female) completed a follow-up interview in 2005-2009 (70.6% of those not deceased). Average age at follow-up was 58.3 (SD=4.9) years for males and 55.0 (SD=4.1) years for females. Longitudinal data was obtained on their drug use, treatment participation, and criminal justice status over the follow-up period. Trajectory group modeling was used to identify distinctive trajectory groups based on monthly averages of heroin and other drug use per year; group differences were examined.

RESULTS

Four heroin and five alcohol and other drug (AOD) trajectory groups were identified. A greater proportion of women (60%) were in the "rapid decrease" heroin group (odds of use less than 10% by 10 years following initiation of use) as compared with the other groups. More rapid decrease of heroin use was associated with increases in AOD use, whereas a gradual decrease in heroin use was associated with a gradual decrease in AOD use. More school problems and earlier age at onset of heroin use and first arrest were associated with more persistent heroin use.

CONCLUSION

Heroin-use trajectories were linked with changes in AOD use. Childhood antecedents of heroin-use trajectories were identified as well as gender differences.

The Dutch Cannabis Dependence (CanDep) study on the course of frequent cannabis use and dependence: objectives, methods and sample characteristics

This paper presents an overview of the prospective cohort design of the Dutch Cannabis Dependence (CanDep) study, which investigates (i) the three-year natural course of frequent cannabis use (≥ three days per week in the past 12 months) and cannabis dependence; and (ii) the factors involved in the transition from frequent non-dependent cannabis use to cannabis dependence, and remission from dependence. Besides its scientific relevance, this knowledge may contribute to improve selective and indicated prevention, early detection, treatment and cannabis policies. The secondary objectives are the identification of factors related to treatment seeking and the validation of self report measures of cannabis use. Between September 2008 and April 2009, baseline data were collected from 600 frequent cannabis users with an average age of 22.1 years, predominantly male (79.3%) and an average cannabis use history of 7.1 years; 42.0% fulfilled a (12-month DSM-IV) diagnosis of cannabis dependence. The response rate was 83.7% after the first follow up at 18 months. The second and last follow-up is planned at 36 months. Computer assisted personal interviews (CAPI) were conducted which covered: cannabis use (including detailed assessments of exposure, motives for use and potency preference); use of other substances; DSM-IV internalizing and externalizing mental disorders; treatment seeking; personality; life events; social support and social functioning.

Probability and predictors of remission from life-time nicotine, alcohol, cannabis or cocaine dependence: results from the National Epidemiologic Survey on Alcohol and Related Conditions

AIM

To estimate the general and racial/ethnic specific cumulative probability of remission from nicotine alcohol cannabis or cocaine dependence, and to identify predictors of remission across substances.

DESIGN

Data were collected from structured diagnostic interviews using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV version.

SETTING

The 2001-2002 National Epidemiological Survey of Alcohol and Related Conditions (NESARC) surveyed a nationally representative sample from US adults (n = 43,093) selected in a three-stage sampling design.

PARTICIPANTS

The subsamples of individuals with life-time DSM-IV diagnosis of dependence on nicotine (n = 6937), alcohol (n = 4781), cannabis (n = 530) and cocaine (n = 408).

MEASUREMENTS

Cumulative probability estimates of dependence remission for the general population and across racial/ethnic groups. Hazard ratios for remission from dependence.

FINDINGS

Life-time cumulative probability estimates of dependence remission were 83.7% for nicotine, 90.6% for alcohol, 97.2% for cannabis and 99.2% for cocaine. Half of the cases of nicotine, alcohol, cannabis and cocaine dependence remitted approximately 26, 14, 6 and 5 years after dependence onset, respectively. Males, Blacks and individuals with diagnosis of personality disorders and history of substance use comorbidity exhibited lower hazards of remission for at least two substances.

CONCLUSIONS

A significant proportion of individuals with dependence on nicotine, alcohol, cannabis or cocaine achieve remission at some point in their life-time, although the probability and time to remission varies by substance and racial/ethnic group. Several predictors of remission are shared by at least two substances, suggesting that the processes of remission overlap. The lower rates of remission of individuals with comorbid personality or substance use disorders highlight the need for providing coordinated psychiatric and substance abuse interventions.