Mortality following treatment for cannabis use disorders: Predictors and causes

Association of substance use with suicide mortality: An updated systematic review and meta-analysis

Background

Rates of suicide mortality and substance use have increased globally. We updated and extended existing systematic reviews of the association between substance use and suicide.

Methods

This systematic review and meta-analysis explored the association between substance use and suicide mortality in peer reviewed, longitudinal cohort studies published from 2003 through 2024. Risk of bias was assessed using the Newcastle-Ottawa Scale. Pooled data were analyzed using a quality effects model. Meta-regression was used to assess the effect of moderation by study quality. Asymmetry in funnel plots and Doi plots were used to detect reporting bias.

Findings

The analysis involved 47 studies from 12 countries. Substance misuse (SMR: 5.58, 95 % CI: 3.63-8.57, I2: 99 %) was significantly associated with risk for suicide. Alcohol (SMR: 65.39, 95 % CI: 3.02-19.62, I2: 99 %), tobacco (SMR: 1.83, 95 % CI: 1.20-2.79, I2: 83 %), opioid (SMR: 5.46, 95 % CI: 3.66-8.15, I2: 96 %), cannabis (SMR 3.31, 95 % CI: 1.42-7.70, I2: 95 %), and amphetamine (SMR 11.97, 95 % CI: 3.13-45.74, I2: 99 %) misuse were each linked to higher rates of suicide mortality. The association between substance misuse and suicide was stronger for females (SMR: 12.37, 95 % CI: 7.07-21.63, I2: 98 %) than males (SMR: 5.21, 95 % CI: 3.09-8.78, I2: 99 %) overall and in analyses of specific substances. Further disaggregated data were not available to sufficiently explore for potential health inequities across social factors.

Conclusions

This meta-analysis highlights that substance misuse remains a significant suicide risk factor. It underscores the need for universal and targeted prevention and equitable access to effective interventions.

Cannabis Use Disorder Emergency Department Visits and Hospitalizations and 5-Year Mortality

Importance

Cannabis use disorders (CUD) are associated with adverse health effects, including mental disorders and motor vehicle collision-related injuries. However, little is known about whether CUDs are associated with increased mortality risk.

Objective

To examine whether individuals receiving incident hospital-based care (an emergency department visit or hospitalization) for a CUD is associated with increased risk of death.

Design, Setting, and Participants

This population-based retrospective cohort study included all individuals aged 15 to 105 years living in Ontario, Canada, between 2006 and 2021 (n = 11 622 571 individuals). Overall and cause-specific mortality were compared between individuals with incident hospital-based CUD care and age- and sex-matched members of the general population or individuals with hospital-based care for other substance use disorders using cause-specific hazard models adjusted for comorbid mental health, substance use, and chronic health conditions. Statistical analysis was performed from September to December 2024.

Exposure

Incident hospital-based CUD care.

Main Outcomes and Measures

Overall and cause-specific mortality identified using vital statistics.

Results

The matched analysis included 527 972 individuals (mean [SD] age, 29.9 [13.6] years; 330 034 [62.5%] female) with a median (IQR) follow-up of 5 (3-9) years; 106 994 had incident CUD. Within 5 years of incident hospital-based CUD care, 3770 individuals (3.5%) died compared with 3770 (0.6%) of matched general population members. After adjusting for comorbid conditions, individuals with incident hospital-based CUD care were at increased risk of death relative to the general population (adjusted hazard ratio [aHR], 2.79 [95% CI, 2.62-2.97]). Individuals with hospital-based CUD care were at increased risk of all investigated types of death and particularly elevated risk of death by suicide (aHR, 9.70 [95% CI, 6.04-15.57]), trauma (aHR, 4.55 [95% CI, 3.55-5.82]), opioid poisoning (aHR, 5.03 [95% CI, 2.86-8.84]), other drug poisonings (aHR, 4.56 [95% CI, 3.11-6.68]), and lung cancer (aHR, 3.81 [95% CI, 2.39-6.07]) relative to the general population. Compared with an individual with hospital-based care for CUD, individuals with hospital-based care for alcohol (aHR, 1.30 [95% CI, 1.26-1.34]), stimulants (aHR, 1.69 [95% CI, 1.62-1.75]), and opioids (aHR, 2.19 [95% CI, 2.10-2.27]) were at relatively increased risk of death within 5 years.

Conclusions and Relevance

In this cohort study of all residents of Ontario, Canada, individuals with incident hospital-based CUD care were at markedly increased risk of death compared with the general population. These findings suggest important clinical and policy implications, given global trends toward cannabis legalization and market commercialization accompanied by increasing cannabis use and CUDs.

Suicide Attempts in an Italian Population with Cannabis Use Disorders: Results of a Follow-Up Study

The relationship between cannabis use and suicidal behavior is complex, with no consensus in the literature. We used electronic health records of national health services to identify individuals who received a diagnosis of Cannabis Use Disorder in the Metropolitan area of Bologna from 2009 to 2019. In this cohort we identified accesses to Emergency Departments for suicide attempts from 2009 to 2019. The Crude Suicide Rate for 1,000 Person Years was 2.5, higher in females, in patients with Alcohol Use Disorders, with any psychiatric diagnosis, within one year from the first visit, and during the COVID-19 period. The risk was over 22 times higher than in the general population. Considering the high prevalence of cannabis use in the general population and the consequent risk of Cannabis Use Disorders, these data suggest the importance of a clinical evaluation for suicidal risk.

Association of semaglutide with reduced incidence and relapse of cannabis use disorder in real-world populations: a retrospective cohort study

Cannabis is the most frequently used illicit drug in the United States with more than 45 million users of whom one-third suffer from a cannabis use disorder (CUD). Despite its high prevalence, there are currently no FDA-approved medications for CUD. Patients treated with semaglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA) approved for treating type 2 diabetes (T2D) and for weight management have reported reduced desire to drink and smoke. Preclinical studies have shown that semaglutide decreased nicotine and alcohol consumption. Preclinical and preliminary clinical evidence of semaglutide's potential beneficial effects on various substance use disorders led us to evaluate if it pertained to CUD. In this retrospective cohort study of electronic health records (EHRs) from the TriNetX Analytics Network, a global federated health research network of approximately 105.3 million patients from 61 large healthcare organizations in the US, we aimed to assess the associations of semaglutide with both incident and recurrent CUD diagnosis compared to non-GLP-1RA anti-obesity or anti-diabetes medications. Hazard ratio (HR) and 95% confidence intervals (CI) of incident and recurrent CUD were calculated for 12-month follow-up by comparing propensity-score matched patient cohorts. The study population included 85,223 patients with obesity who were prescribed semaglutide or non-GLP-1RA anti-obesity medications, with the findings replicated in 596,045 patients with T2D. In patients with obesity (mean age 51.3 years, 65.6% women), semaglutide compared with non-GLP-1RA anti-obesity medications was associated with lower risk for incident CUD in patients with no prior history CUD (HR: 0.56, 95% CI: 0.42-0.75), and recurrent CUD diagnosis in patients with a prior history CUD (HR: 0.62, 95% CI: 0.46-0.84). Consistent reductions were seen for patients stratified by gender, age group, race and in patients with and without T2D. Similar findings were replicated in the study population with T2D when comparing semaglutide with non-GLP-1RA anti-diabetes medications for incident CUD (HR: 0.40, 95% CI: 0.29-0.56) and recurrent CUD (HR: 0.66, 95% CI: 0.42-1.03). While these findings provide preliminary evidence of the potential benefit of semaglutide in CUD in real-world populations, further preclinical studies are warranted to understand the underlying mechanism and randomized clinical trials are needed to support its use clinically for CUD.

Excess mortality among individuals who have undergone addiction treatment: a study from Greenland

In Greenland, where addiction-related concerns significantly affect well-being, research has explored alcohol's impact on health and mortality. However, no studies have focused on mortality among those who received addiction treatment. This study investigates whether individuals treated for addiction in Greenland experience elevated mortality rates compared to the general population. The study encompassed individuals receiving addiction treatment through the national system between 2012 and December 31, 2022. Data on treatment were sourced from the National Addiction Database, and Statistics Greenland. Person-years at risk were calculated and used to estimate crude mortality rates (CMRs). Adjusted standardized mortality rates (SMRs), accounting for age, sex, and calendar year, were estimated using an indirect method based on observed and expected deaths. Of the 3286 in treatment, 53.9% were women, with a median age of 37. About a third had undergone multiple treatment episodes, and 60.1% received treatment in 2019 or later. The cohort was followed for a median of 2.89 years, yielding 12,068 person-years. The overall CMR was 7.79 deaths per 1000 person-years, with a SMR of 1.42 (95% confidence interval: 1.15; 1.74). Significantly, SMRs differed by age at treatment entry, with younger groups exhibiting higher SMRs (p value = .021). This study found that individuals seeking treatment for addiction problems in Greenland had a higher mortality rate than the general population. Importantly, these SMRs were substantially lower than those observed in clinical populations in other countries.

Mortality during and after specialist alcohol and other drug treatment: Variation in rates according to principal drug of concern and treatment modality

INTRODUCTION

For people accessing treatment for problems with drugs other than opioids, little is known about the relationship between treatment and mortality risk, nor how mortality risk varies across treatment modalities. We addressed these evidence gaps by determining mortality rates during and after treatment for people accessing a range of treatment modalities for several drugs of concern.

METHODS

We conducted a cohort study using linked data on publicly funded specialist alcohol or other drug treatment service use and mortality for people receiving treatment in New South Wales between January 2012 and December 2018. We calculated and compared during-treatment and post-treatment crude mortality rates and age- and sex-standardised mortality rates, separately for each principal drug of concern and modality.

RESULTS

Over the study period, 45,026 people accessed treatment for problems with alcohol, 26,407 for amphetamine-type stimulants, 23,047 for cannabinoids and 21,556 for opioids. People treated for alcohol or opioid problems had higher crude mortality rates (1.48, 1.91, 1.09 per 100 person years, respectively) than those with problems with amphetamine-type stimulants or cannabinoids (0.46, 0.30 per 100 person years, respectively). Mortality rates differed according to treatment status and modality only among people with alcohol or opioid problems.

DISCUSSION AND CONCLUSIONS

The observed variation in mortality rates indicates there is scope to reduce mortality among people accessing treatment with alcohol or opioid problems. Future research on mortality among people accessing drug and alcohol treatment should account for the variation in mortality by drug of concern and treatment modality.

Predictors of Death From Physical Illness or Accidental/Intentional Causes Among Patients With Substance-Related Disorders

OBJECTIVE

This study identified patient clinical and sociodemographic characteristics, and, more originally, service use patterns as predictors of death from physical illness or accidental/intentional causes.

METHODS

A cohort of 19,015 patients with substance-related disorders (SRD) from 14 addiction treatment centers was investigated using Quebec (Canada) health administrative databases. Death was studied over a 3-year period (April 1, 2013, to March 31, 2016), and most predictors from 4 years to 12 months prior to the time of death, using multinomial logistic regression.

RESULTS

Frequent emergency department (ED) use strongly predicted both causes of death, suggesting that outpatient care responded inadequately to patient needs. Only receipt of specialized SRD and psychiatric care significantly decreased the risk of death from physical illness, with trends toward significance for accidental/intentional death. Hospitalization, greater material deprivation and having SRD-chronic physical illnesses or alcohol-related disorders most strongly predicted risk of death from physical illness. Sociodemographic characteristics, mainly social deprivation, were more likely to predict accidental/intentional death.

CONCLUSIONS

Outpatient services could be improved by increasing outreach and motivational interventions and, for ED and hospital units, better screening, brief intervention, and referral to treatment, particularly for men and socially deprived patients at high risk of accidental/intentional death. Patients with more severe health conditions, notably older or materially deprived men at higher risk of death from physical illness, could benefit from programs like assertive community treatment or intensive case management that respond well to diverse and continuous patient needs. Collaborative care between SRD and health services could also be improved.

Profiles of quality of outpatient care use, associated sociodemographic and clinical characteristics, and adverse outcomes among patients with substance-related disorders

BACKGROUND

This study identified patient profiles in terms of their quality of outpatient care use, associated sociodemographic and clinical characteristics, and adverse outcomes based on frequent emergency department (ED) use, hospitalization, and death from medical causes.

METHODS

A cohort of 18,215 patients with substance-related disorders (SRD) recruited in addiction treatment centers was investigated using Quebec (Canada) health administrative databases. A latent class analysis was produced, identifying three profiles of quality of outpatient care use, while multinomial and logistic regressions tested associations with patient characteristics and adverse outcomes, respectively.

RESULTS

Profile 1 patients (47% of the sample), labeled "Low outpatient service users", received low quality of care. They were mainly younger, materially and socially deprived men, some with a criminal history. They had more recent SRD, mainly polysubstance, and less mental disorders (MD) and chronic physical illnesses than other Profiles. Profile 2 patients (36%), labeled "Moderate outpatient service users", received high continuity and intensity of care by general practitioners (GP), while the diversity and regularity in their overall quality of outpatient service was moderate. Compared with Profile 1, they  were older, less likely to be unemployed or to live in semi-urban areas, and most had common MD and chronic physical illnesses. Profile 3 patients (17%), labeled "High outpatient service users", received more intensive psychiatric care and higher quality of outpatient care than other Profiles. Most Profile 3 patients lived alone or were single parents, and fewer lived in rural areas or had a history of homelessness, versus Profile 1 patients. They were strongly affected by MD, mostly serious MD and personality disorders. Compared with Profile 1, Profile 3 had more frequent ED use and hospitalizations, followed by Profile 2. No differences in death rates emerged among the profiles.

CONCLUSIONS

Frequent ED use and hospitalization were strongly related to patient clinical and sociodemographic profiles, and the quality of outpatient services received to the severity of their conditions. Outreach strategies more responsive to patient needs may include motivational interventions and prevention of risky behaviors for Profile 1 patients, collaborative GP-psychiatrist care for Profile 2 patients, and GP care and intensive specialized treatment for Profile 3 patients.

Cannabis and Intentional Self-injury: a Narrative Review

Purpose of Review

Observational studies assessing the association of cannabis use with subsequent intentional self-injury have reported mixed findings. Longitudinal studies examining the association of cannabis use with subsequent suicide death are notably rare. Our objective was to review longitudinal studies examining cannabis use and subsequent self-harm, suicide attempt, or suicide death.

Recent Findings

Few population-based studies have focused on self-harm with considerable variability across studies in how this outcome has been operationalized. Studies assessing the association between cannabis use and suicide attempt are equivocal in their conclusions and heterogenous in terms of samples utilized and assessment of confounding bias. The results of one meta-analysis were suggestive of dose dependency. For suicide death, the findings are inconsistent, and there is reason for concern of selection bias.

Summary

The existing evidence base on these associations is not yet rigorous enough to allow drawing conclusions on causality. However, cannabis might be seen as an adverse prognostic marker for intentional self-injury.

Mortality risk for individuals with cannabis use disorders in relation to alcohol use disorders: Results of a follow-up study

BACKGROUND

There are few studies on mortality on individuals entering treatment for cannabis use disorders.

OBJECTIVES

To estimate mortality risk for individuals treated for cannabis use disorders comparing patients with concomitant alcohol use disorders to those with only cannabis use disorders.

METHODS

Follow-up study on 1136 residents in Northern Italy who turned to health services following problems caused by cannabis use disorders between 2009 and 2019. Individuals with concomitant use of opioids, amphetamines, cocaine, or injecting drugs were excluded. Crude mortality rates per 1000 Person Years (CMR), and standardized mortality ratios adjusted for age, sex and calendar year (SMR) were calculated.

RESULTS

Elevated CMRs (CMR 4.4, 3-6.4), higher among patients with concomitant alcohol use disorders (CMR 10.2, 6.6-15.6) compared to those with only cannabis use disorders (CMR 1.8, 0.9-3.6) were found. Regarding excess mortality with respect to the general population, SMRs were higher and statistically significant (SMR 5.4, 3.7-7.8), both among patients with concomitant alcohol use disorders (SMR 10.2, 6.6-15.6) and among those with only cannabis use disorders (SMR 2.3, 1.1-4.5).

CONCLUSIONS

The results of this study show that individuals with only cannabis use disorders have a lower mortality risk compared to those with both cannabis and alcohol use disorders.

Association between cannabis use and suicidal behavior: A systematic review of cohort studies

The use of cannabis is highly prevalent worldwide, with known short and long-term adverse effects. However, the relationship between cannabis use and suicidal behavior remains relatively unexplored and this paper aims to unify existing literature on the topic. A systematic review was conducted using MEDLINE, Embase, PsycINFO and LILACS databases with a supplementary search to identify cohort articles published up to January 2020, with no age delimitation for the samples. This review aimed to address the relationship between cannabis use and suicidal behavior, defined as suicidal ideation, attempted suicide or completed suicide. Twenty-two articles were identified, with no clear consensus, irrespective of the outcome being investigated. This was the case even when taking into consideration only those studies with a sound methodology (according to the Newcastle-Ottawa scale). Studies that identified an association explored the importance of the endocannabinoid system as well as the psychosocial context of the individual while developing suicidal behavior, with certain studies demonstrating that greater intensity or precocity of cannabis use increases the strength of this association. The relationship between cannabis use and suicidal behavior is complex, with no consensus in the literature. Further studies with standardized definitions for cannabis use, including frequency of use, along with improved controls for confounding variables are needed.

Does cannabis use in adolescence predict self-harm or suicide? Results from a Finnish Birth Cohort Study

OBJECTIVE

Longitudinal studies examining the association between adolescent cannabis use and self-harm are rare, heterogeneous and mixed in their conclusions. We study this association utilizing a large general population-based sample with prospective data.

METHODS

The Northern Finland Birth Cohort 1986 (n = 6582) with linkage to nationwide register data was used to study the association of self-reported cannabis use at age 15-16 years and self-harm and suicide death until age 33 (until year 2018), based on register information. Cox regression analysis with Hazard Ratios (HR) and 95% confidence intervals (CI) was used. Psychiatric disorders, parental psychiatric disorders and other substance use were considered as confounders.

RESULTS

In all, 6582 (49.2% male) were included in the analysis, and 377 adolescents (5.7%) reported any cannabis use until the age of 15-16 years. Based on register information, 79 (55.7% male) had visited in health care services due to self-harm, and 22 (90.1% male) had died by suicide. In crude analyses, adolescent cannabis use was associated with self-harm (HR = 3.93; 95% CI 2.24-6.90). The association between cannabis use and self-harm remained statistically significant after adjusting for sex, psychiatric disorders at baseline, frequent alcohol intoxications, other illicit drug use, and parental psychiatric disorders (HR 2.06; 95% CI 1.07-3.95). In contrast, the association of cannabis use with suicide did not reach statistical significance even in crude analysis (HR 2.60; 95% CI 0.77-8.78).

CONCLUSION

Cannabis use in adolescence may increase risk of self-harm independent of adolescent psychopathology and other substance use.

Associations of Suicidality Trends With Cannabis Use as a Function of Sex and Depression Status

IMPORTANCE

During the past decade, cannabis use among US adults has increased markedly, with a parallel increase in suicidality (ideation, plan, attempt, and death). However, associations between cannabis use and suicidality among young adults are poorly understood.

OBJECTIVE

To determine whether cannabis use and cannabis use disorder (CUD) are associated with a higher prevalence of suicidality among young adults with or without depression and to assess whether these associations vary by sex.

DESIGN, SETTING, AND PARTICIPANTS

This survey study examined data from 281 650 adults aged 18 to 34 years who participated in the National Surveys on Drug Use and Health. Data were collected from January 1, 2008, to December 31, 2019.

EXPOSURES

Prevalence of past-year daily or near-daily cannabis use (≥300 days in the past year), CUD, and major depressive episode (MDE). Past-year CUD and MDE were based on DSM-IV diagnostic criteria.

MAIN OUTCOMES AND MEASURES

Past-year suicidal ideation, plan, and attempt.

RESULTS

Among the 281 650 adults aged 18 to 34 (men, 49.9% [95% CI, 49.6%-50.2%]; women, 50.1% [95% CI, 49.8%-50.4%]) included in the analysis, past-year suicidal ideation and plan along with daily cannabis use increased among all examined sociodemographic subgroups (except daily cannabis use among current high-school students), and past-year suicide attempt increased among most subgroups. National trends in adjusted prevalence of past-year suicidal ideation, plan, and attempt varied by daily and nondaily cannabis use and CUD among adults with or without MDE. After controlling for MDE, CUD, cannabis use status, and potential confounding factors, the adjusted prevalence of suicidal ideation, plan, and attempt increased 1.4 to 1.6 times from the 2008-2009 to 2018-2019 periods (adjusted risk ratio [ARR] for suicidal ideation, 1.4 [95% CI, 1.3-1.5]; ARR for suicide plan, 1.6 [95% CI, 1.5-1.9]; ARR for suicide attempt, 1.4 [95% CI, 1.2-1.7]), with 2008 to 2009 as the reference period. Past-year CUD, daily cannabis use, and nondaily cannabis use were associated with a higher prevalence of past-year suicidal ideation, plan, and attempt in both sexes (eg, among individuals without MDE, prevalence of suicidal ideation for those with vs without CUD was 13.9% vs 3.5% among women and 9.9% vs 3.0% among men; P < .001), but significantly more so in women than men (eg, suicide plan among those with CUD and MDE was 52% higher for women [23.7%] than men [15.6%]; P < .001).

CONCLUSIONS AND RELEVANCE

From 2008 to 2019, suicidal ideation, plan, and attempt increased 40% to 60% over increases ascribed to cannabis use and MDE. Future research is needed to examine this increase in suicidality and to determine whether it is due to cannabis use or overlapping risk factors.

Association of Cannabis Use With Self-harm and Mortality Risk Among Youths With Mood Disorders

Importance

Cannabis use and cannabis use disorder (CUD) are common among youths and young adults with mood disorders, but the association of CUD with self-harm, suicide, and overall mortality risk is poorly understood in this already vulnerable population.

Objective

To examine associations of CUD with self-harm, suicide, and overall mortality risk in youths with mood disorders.

Design, Setting, and Participants

A population-based retrospective cohort study was performed using Ohio Medicaid claims data linked with death certificate data. The analysis included 204 780 youths (aged 10-24 years) with a diagnosis of mood disorders between July 1, 2010, and December 31, 2017, who were followed up to 365 days from the index diagnostic claim until the end of enrollment, the self-harm event, or death. Statistical analysis was performed from April 4 to July 17, 2020.

Exposure

Physician-diagnosed CUD defined using outpatient and inpatient claims from 180 days prior to the index mood disorder diagnostic claim through the 365-day follow-up period.

Main Outcomes and Measures

Nonfatal self-harm, all-cause mortality, and deaths by suicide, unintentional overdose, motor vehicle crashes, and homicide. Marginal structural models using inverse probability weights examined associations between CUD and outcomes.

Results

This study included 204 780 youths (133 081 female participants [65.0%]; mean [SD] age at the time of mood disorder diagnosis, 17.2 [4.10] years). Cannabis use disorder was documented for 10.3% of youths with mood disorders (n = 21 040) and was significantly associated with older age (14-18 years vs 10-13 years: adjusted risk ratio [ARR], 9.35; 95% CI, 8.57-10.19; and 19-24 years vs 10-13 years: ARR, 11.22; 95% CI, 10.27-12.26), male sex (ARR, 1.79; 95% CI, 1.74-1.84), Black race (ARR, 1.39; 95% CI, 1.35-1.44), bipolar or other mood disorders (bipolar disorders: ARR, 1.24; 95% CI, 1.21-1.29; other mood disorders: ARR, 1.20; 95% CI, 1.15-1.25), prior history of self-harm (ARR, 1.66; 95% CI, 1.52-1.82), previous mental health outpatient visits (ARR, 1.26; 95% CI, 1.22-1.30), psychiatric hospitalizations (ARR, 1.66; 95% CI, 1.57-1.76), and mental health emergency department visits (ARR, 1.54; 95% CI, 1.47-1.61). Cannabis use disorder was significantly associated with nonfatal self-harm (adjusted hazard ratio [AHR], 3.28; 95% CI, 2.55-4.22) and all-cause mortality (AHR, 1.59; 95% CI, 1.13-2.24), including death by unintentional overdose (AHR, 2.40; 95% CI, 1.39-4.16) and homicide (AHR, 3.23; 95% CI, 1.22-8.59). Although CUD was associated with suicide in the unadjusted model, it was not significantly associated in adjusted models.

Conclusions and Relevance

Cannabis use disorder is a common comorbidity and risk marker for self-harm, all-cause mortality, and death by unintentional overdose and homicide among youths with mood disorders. These findings should be considered as states contemplate legalizing medical and recreational marijuana, both of which are associated with increased CUD.

Immigration Status and Substance Use Disorder-related Mortality in Sweden: A National Longitudinal Registry Study

OBJECTIVES

First-generation immigrants, in many countries, are healthier than their native counterparts. This study examined the association between first- and second-generation immigrant status and alcohol- or drugs other than alcohol-related (primarily opioids) mortality for those with risky substance use.

METHODS

A Swedish longitudinal, 2003 to 2017, registry study combined Addiction Severity Index (ASI) assessment data with mortality data (n = 15 601). Due to missing data, the analysis sample for this study was 15 012. Multivariate models tested the relationship between immigration status and drugs other than alcohol or alcohol-related mortality, controlling for demographics and the 7 ASI composite scores (CS).

RESULTS

Age, a higher ASI CS for alcohol, a lower ASI CS family and social relationship, a lower ASI CS for drug use and a higher ASI CS for health significantly predicted mortality because of alcohol-related causes. Higher ASI CS for drugs other than alcohol, employment, and health, age, male sex, and immigration status predicted drugs other than alcohol, related mortality. Individuals born in Nordic countries, excluding Sweden, were 1.76 times more likely to die of drugs other than alcohol compared with their Swedish counterparts. Individuals born outside a Nordic country (most common countries: Iran, Somalia, Iraq, Chile) were 61% less likely to die of drugs other than alcohol compared with their Swedish counterparts. Those with parents born outside Nordic countries were 54% less likely to die of drugs other than alcohol.

DISCUSSION

Research is needed on why people with risky substance use from Nordic countries (not Sweden) residing in Sweden, have higher mortality rates because of drugs other than alcohol (primarily opioids drugs other than alcohol compared with the other population groups in our study). Findings indicate that ASI CSs are strong predictors of future health problems including mortality due to alcohol and other drug-related causes.

Prediction of psychiatric comorbidity on premature death in a cohort of patients with substance use disorders: a 42-year follow-up

BACKGROUND

We need to better understand how the use of different substances and psychiatric comorbidity influence premature death generally and cause-specific death by overdose, intoxication and somatic disorders in people with substance use disorders.

METHOD

A cohort of 1405 patients consecutively admitted to a Swedish detoxification unit for substance use disorders in 1970-1995 was followed-up for 42 years. Substances were identified by toxicological analyses. Mortality figures were obtained from a national registry. Causes of death were diagnosed by forensic autopsy in 594 patients deceased by 2012. Predictions were calculated by competing risks analysis.

RESULTS

Forty-two per cent of the cohort died during follow-up; more men than women (46.3% vs 30.4%). The standardised mortality ratio (SMR) was calculated as the ratio of observed deaths in males and females in specific age groups in the cohort versus expected deaths in corresponding groups in the general population. SMR was 5.68 for men (CI 95%; 5.04-6.11) and 4.98 (CI 95%; 4.08-5.88) for women. The crude mortality rate (number of deaths divided by number of person observation years) was 2.28% for men and 1.87% for women. Opiates predicted increased risk of premature death while amphetamine and cannabis predicted lower risk. Comorbid psychiatric disorders were identified in 378 cases and personality disorders in 763 cases. Primary psychoses or mood/depression and anxiety disorders predicted a higher risk of premature mortality. Death by overdose was predicted by male gender, younger age at admission to substance treatment, opiate use, and comorbid depression and anxiety syndromes. Cannabis and amphetamine use predicted a lower risk of overdose. Death by intoxication was predicted by male gender, use of sedatives/hypnotics or alcohol/mixed substances, primary psychoses and depression/anxiety syndromes. Premature death by somatic disorder was predicted by male gender and alcohol/mixed abuse.

CONCLUSION

Psychiatric comorbid disorders were important risk factors for premature drug-related death. Early identification of these factors may be life-saving in the treatment of patients with substance use disorders.

From Substance Use Disorders in Life to Autopsy Findings: A Combined Case-Record and Medico-Legal Study

Objectives: Several studies have shown mortality and suicide risk in substance use disorders, and autopsy findings with respect to the used substances. However, there seems to be a gap in the knowledge about substances misused in life and at death at the within-person level. Methods: All consecutive, autopsied patients during 1993 to 1997, who had been in contact with the Addiction Centre in Malmö from 1968, were investigated (365 subjects). Drug misuse in the long-term course noted in case records was related to autopsy findings. Self-inflicted death (suicide/undetermined suicide/accidental overdose) was compared with natural death. Results: Benzodiazepine misuse was associated with a high risk of autopsy findings of the substance in suicide and death of undetermined intent. It was also associated among non-misusers, but less so. An alcohol level above 1‰ was found more often in self-inflicted death. Prescription opioids at autopsy were mainly found in self-inflicted death among non-misusers. Heroin misuse was related to overdose. Central nervous system stimulants (CNS-S) and cannabis were rarely found in self-inflicted death among previous misusers. The overlap between depression in life and antidepressants at death was low. Conclusions: Benzodiazepines and alcohol seem to disinhibit suicidal tendencies. Suicide risk among users of cannabis and CNS-S may be related to other risk factors than acute use. Implications for suicide prevention are discussed.

Perceptions of plain packaging and health warning labels for cannabis among young adults: findings from an experimental study

BACKGROUND

There is strong evidence that plain cigarette packaging and health warning labels (HWLs) reduce brand appeal and increase health knowledge. There is limited evidence examining this population-level public health approach for cannabis packaging. This issue is of particular importance in light of the recent legalization of recreational cannabis in Canada. The current study examined perceptions of plain packaging and HWLs for cannabis packages among young adults.

METHODS

An online experimental study was conducted with a sample of university students in Alberta, Canada (n = 656). Respondents were randomly assigned to view cannabis packages in one of four conditions: Condition 1: branded pack, Condition 2: plain pack (uniform color, brand imagery removed, standardized font), Condition 3: branded pack with a HWL, and Condition 4: plain pack with a HWL. Respondents in Conditions 3 and 4 viewed five text-based HWLs, each corresponding to a health effect associated with cannabis use: (1) brain development, (2) mental health issues, (3) impaired driving, (4) nonlethal overdose, and (5) addiction. After viewing packs, respondents rated packs and health warnings on various measures.

RESULTS

Branded packages without HWLs were rated as most appealing compared to all other packs (p < 0.001 for all contrasts). No differences were found in ratings of appeal when comparing branded and plain packs with HWLs. Warning messages for cognitive development and impaired driving were rated highest on levels of perceived effectiveness, believability, and fear, whereas the addiction warning was rated among the lowest. In general, there were gaps in health knowledge related to cannabis use, however after viewing packs with warnings (compared to viewing packs without warnings) levels of health knowledge increased across all health effects (p < 0.01 for all). Lastly, a significant majority of young adults reported they would purchase the branded pack without a HWL (39.5%), compared to all other pack types (p < 0.05 for all contrasts). The lowest proportion of young adults reported they would purchase a plain pack with a HWL (1.1%).

CONCLUSIONS

Plain packaging and health warnings may reduce brand appeal and increase health knowledge among young adults.

Mortality and Cause of Death-A 30-Year Follow-Up of Substance Misusers in Sweden

BACKGROUND

This article presents a 30-year follow-up study of a cohort of 1163 substance misusers who were in inpatient treatment in the early 1980s. Data was originally collected in the Swedish Drug Addict Treatment Evaluation (SWEDATE).

OBJECTIVES

The aim is to examine the overall mortality and identify causes of death in different groups based on self-reported most dominant substance misuse among those who have died during January 1984-December 2013.

METHODS

SWEDATE-data was linked to the National Cause of Death Register. Five mutually exclusive study groups were created based on self-reported most dominant substance misuse for the last 12 months before intake to treatment: Alcohol, Cannabis, Stimulants, Opiates, and Other. The Standardized Mortality Ratio (SMR) was calculated.

RESULTS

During the follow-up, 40% died. SMR is 10.3 for women and 11.7 for men. The study groups differed regarding SMR; 13.1 in the Alcohol group, 9.2 in the Cannabis group, 9.6 in the Stimulants group, 16.7 in the Opiates group and 10.8 in the Other group. Drug related death was the most common cause of death (28% only underlying, 19% both underlying and contributing) followed by alcohol related reasons (17% vs. 9%).

CONCLUSIONS

Alcohol misuse among substance abusers might have a negative impact on mortality rates. Methodological changes in how drug related deaths is registered affects the interpretation of the statistics of cause of death. Further analysis on the relation between drug related cause of death and drug misuse related death is needed.

Who seeks treatment for cannabis use? Registered characteristics and physical, psychological and psychosocial problem indicators among cannabis patients and matched controls

BACKGROUND

There has been an absolute and relative increase in the number of patients with cannabis-related disorders as the principal diagnosis in many countries in recent years. Cannabis is now the most frequently mentioned problem drug reported by new patients in Europe, and cannabis patients constituted one third of all drug treatment patients in 2015. There is limited knowledge with regard to patient characteristics, the extent and types of health and psychosocial problems, as well as their association with long-term outcomes.

METHODS

We analysed indicators of physical, psychological and psychosocial problems of all patients admitted to treatment for cannabis use in Norway in 2009 and 2010 using register data and observed them to the end of 2013. Patient characteristics and outcomes were compared to a randomly drawn control group with corresponding age and gender distribution. Using logistic regression of prospective data, we studied associations between baseline characteristics and work and study status in 2013.

RESULTS

Cannabis patients tended to be relatively young and the large majority were male. They had parents who were less highly educated compared to controls, while there was no difference in migration background. In addition to an increased risk of premature death, nearly half of the patients received a secondary psychological diagnosis and a similar proportion received an additional substance use diagnosis during the 4-5 years of study follow-up. The cannabis patients were less educated than the control group and also less likely to be studying or working at the end of the study period. Entering treatment at a young age, having completed more than secondary education, having a highly-educated mother and not having a secondary diagnosis were factors that were positively associated with being in education or employment at the end of follow-up.

CONCLUSIONS

Data covering the entire Norwegian population of patients admitted primarily for cannabis-related problems showed comprehensive and complex patterns of physical, psychological and psychosocial problems. The prevalence and extent of these problems varied markedly from those of the general population. Work and study outcomes following treatment depended on the seriousness of the condition including co-morbidity as well as social capital.

Cannabis as Secondary Drug Is Not Associated With a Greater Risk of Death in Patients With Opiate, Cocaine, or Alcohol Dependence

BACKGROUND

The health burden of cannabis use in patients with other substance dependencies is not fully understood.

OBJECTIVE

To assess the impact of cannabis use as secondary drug on mortality of patients with other major substance use disorders.

PARTICIPANTS

Patients with opiate, cocaine, or alcohol dependence admitted to detoxification from 2001 to 2010 at a teaching hospital in Badalona, Spain.

MAIN MEASUREMENTS

Sociodemographic characteristics, drug use, medical comorbidities, and urine drug screens were obtained at admission. Deaths were ascertained through clinical records and a death registry. Mortality rates and Cox regression models were used to analyze the association between urinary cannabis and mortality.

RESULTS

A total of 474 patients (20% women) were admitted with a median age of 38 years (interquartile range: 32-44 years). The main substances that motivated admissions were opiates (27%), cocaine (24%), and alcohol (49%). Positive urinary cannabis was detected in 168 patients (35%). Prevalence of cannabis use among patients with opiate, cocaine, or alcohol dependence was 46.5%, 42.9%, and 25.5%, respectively. At admission, 110 (23.7%) patients had human immunodeficiency virus infection and 217 (46.5%) had hepatitis C virus infection. Patients were studied for a median of 5.6 years (interquartile range: 2.6-7.7 years) (2454.7 person-years), and at the end of the study, 50 patients (10.5%) had died, yielding a mortality rate of 2.04 × 100 patient-years (95% confidence interval: 1.53-2.66). There was no association between cannabis detection and overall mortality in the adjusted regression models [hazard ratio (95% confidence interval): 1.12 (0.60-2.00), P = 0.73], but acquired immune deficiency syndrome-related deaths were more frequent in those positive for cannabis (26% vs 2%, P = 0.03).

CONCLUSION

Positive urinary cannabis did not confer an increased risk of death in patients with severe opiate, cocaine or alcohol dependence.

A literature review and meta-analyses of cannabis use and suicidality

BACKGROUND

We lack a review of the epidemiological literature on cannabis use (acute use and chronic-usual quantity/frequency and heavy use) and suicidality (suicide death, suicide ideation, suicide attempt).

METHODS

The English language literature on Medline, PsychInfo, Google Scholar, and public-use databases was searched for original articles, critical review reports, and public use data on cannabis use and suicide for the period ranging from 1990-2015 (February). Odds ratios (OR) from random effects in meta-analyses for any cannabis use and heavy cannabis use were calculated.

RESULTS

The acute cannabis-suicidality literature mostly includes descriptive toxicology reports. In terms of death by suicide, the average positive cannabis rate was 9.50% for studies sampling from all suicides, with higher cannabis detection rates amongst suicide decedents by non-overdose methods. We found only 4 studies providing estimates for any chronic cannabis use and death by suicide (OR=2.56 (1.25-5.27)). After deleting duplicates we found 6 studies on any cannabis use and suicide ideation (OR=1.43 (1.13-1.83)), 5 studies on heavy cannabis use and suicide ideation (OR=2.53 (1.00-6.39)), 6 studies on any cannabis use and suicide attempt (OR=2.23 (1.24-4.00)) and 6 studies on heavy cannabis use and suicide attempt (OR=3.20 (1.72-5.94)).

CONCLUSIONS

We currently lack evidence that acute cannabis use increases imminent risk for suicidality. The evidence tends to support that chronic cannabis use can predict suicidality, but the lack of homogeneity in the measurement of cannabis exposure and, in some instances, the lack of systematic control for known risk factors tempered this finding.

Drop-out from the Swedish addiction compulsory care system

Drop-out of addiction treatment is common, however, little is known about drop-out of compulsory care in Sweden. Data from two national register databases were merged to create a database of 4515 individuals sentenced to compulsory care 2001-2009. The study examined (1) characteristics associated with having dropped out from a first compulsory care episode, (2) the relationship between drop-out and returning to compulsory care through a new court sentence, and (3) the relationship between drop-out and mortality.

METHODS

Multivariable logistic regression analysis was used to address Aim 1 and Cox proportional hazards regression modeling was applied to respond to Aims 2 and 3.

FINDINGS

Age and previous history of crime were significant predictors for drop-out. Clients who dropped out were 1.67 times more likely to return to compulsory care and the hazard of dying was 16% higher than for those who dropped-out.

CONCLUSION

This study finds that 59% of clients assigned to compulsory care drop-out. Younger individuals are significantly more likely to drop-out. Those who drop out are significantly more likely to experience negative outcomes (additional sentence to compulsory care and higher risk of mortality). Interventions need to be implemented that increase motivation of youth to remain in compulsory care.

What has research over the past two decades revealed about the adverse health effects of recreational cannabis use?

AIMS

To examine changes in the evidence on the adverse health effects of cannabis since 1993.

METHODS

A comparison of the evidence in 1993 with the evidence and interpretation of the same health outcomes in 2013.

RESULTS

Research in the past 20 years has shown that driving while cannabis-impaired approximately doubles car crash risk and that around one in 10 regular cannabis users develop dependence. Regular cannabis use in adolescence approximately doubles the risks of early school-leaving and of cognitive impairment and psychoses in adulthood. Regular cannabis use in adolescence is also associated strongly with the use of other illicit drugs. These associations persist after controlling for plausible confounding variables in longitudinal studies. This suggests that cannabis use is a contributory cause of these outcomes but some researchers still argue that these relationships are explained by shared causes or risk factors. Cannabis smoking probably increases cardiovascular disease risk in middle-aged adults but its effects on respiratory function and respiratory cancer remain unclear, because most cannabis smokers have smoked or still smoke tobacco.

CONCLUSIONS

The epidemiological literature in the past 20 years shows that cannabis use increases the risk of accidents and can produce dependence, and that there are consistent associations between regular cannabis use and poor psychosocial outcomes and mental health in adulthood.

The impact of drug use patterns on mortality among polysubstance users in a Canadian setting: a prospective cohort study

Background

Illicit drug use is a well-established risk factor for morbidity and mortality. However, few studies have examined the impact of different drug use patterns on mortality among polysubstance using populations. This study aimed to identify drug-specific patterns of mortality among a cohort of polysubstance using persons who inject drugs (PWIDs).

Methods

PWIDs in Vancouver, Canada were prospectively followed between May 1996 and December 2011. Participants were linked to the provincial vital statistics database to ascertain mortality rates and causes of death. We used multivariate Cox proportional hazards regression to investigate the relationships between drug use patterns (daily alcohol use, heroin injection and non-injection use, cocaine injection, amphetamine injection and non-injection use, crack smoking and speedball injecting) and time to all-cause mortality.

Results

2330 individuals were followed for a median of 61 months (inter-quartile range: 33 – 112). In total, 466 (19.1%) individuals died for an incidence density of 3.1 (95% confidence interval [CI]: 2.8 – 3.4) deaths per 100 person-years. In multivariate analyses, after adjusting for HIV infection and other potential confounders, only daily cocaine injection remained independently associated with all-cause mortality (adjusted hazard ratio [AHR] = 1.36, 95% CI: 1.06 – 1.76).

Conclusions

Although heroin injecting is traditionally viewed as carrying the highest risk of mortality, in this setting, only daily cocaine injecting was associated with all-cause mortality. These findings highlight the urgent need to identify novel treatments and harm reduction strategies for cocaine injectors.

Cannabis use and first manic episode

BACKGROUND

Cannabis is the most commonly abused drug among patients with bipolar disorder. Available data has shown that the risk of psychotic disorders increases with the frequency and intensity of cannabis abuse. The present purpose was to review relevant studies to investigate whether cannabis use can be linked to the onset of mania in bipolar disorder.

METHODS

Articles published between 1972 and December 2013 were searched on Medline and PsychInfo using the following keywords: first manic episode, or onset mania, or bipolar disorder and cannabis. Relevant papers cited in the references of selected articles were further considered for inclusion into the review.

RESULTS

Lifetime use of cannabis among bipolar patients appears to be around 70% and approximately 30% of patients with a bipolar disorder present a comorbidity of cannabis abuse or dependence. Cannabis use is associated with younger age at onset of first mania and with more frequent depressive or manic episodes, although the evidence is somewhat inconsistent. Likewise cannabis consumption is related to poorer outcome and an increased risk of rapid cycling or mixed episodes. In contrast, neuro-cognitive functioning seems to be positively affected in patients with psychiatric comorbidity. While cannabis use often precedes first manic episodes, the causal direction remains to be determined.

LIMITATIONS

Variations in definition of cannabis use/dependence. Lack of controlled studies limiting definite conclusions about a putative causal relationship between cannabis and onset of mania.

CONCLUSIONS

Further investigations are needed to clarify the relationships between cannabis use and first manic episode.