All-cause and cause-specific mortality among people with regular or problematic cocaine use: a systematic review and meta-analysis

Disruption of relapse to cocaine and morphine seeking by LiCl-induced aversive counterconditioning following memory retrieval

Substance use disorder is conceptualized as a form of maladaptive learning, whereby drug-associated memories, elicited by the presence of stimuli related to drug contexts or cues, contribute to the persistent recurrence of craving and the reinstatement of drug-seeking behavior. Hence, use of pharmacology or non-pharmacology way to disrupt drug-related memory holds promise to prevent relapse. Several studies have shown that memories can be unstable and susceptible to modification during the retrieval reactivation phase, termed the "reconsolidation time window". In this study, we use the classical conditioned place preference (CPP) model to investigate the role of aversive counterconditioning on drug-related memories during reconsolidation. Specifically, we uncovered that reconditioning drug cues through counterconditioning with LiCl-induced aversive outcomes following drug memory retrieval reduces subsequent drug-seeking behavior. Notably, the recall of cocaine- or morphine-CPP was eliminated when LiCl-induced aversive counterconditioning was performed 10 min, but not 6 h (outside the reconsolidation time window) after cocaine or morphine memory retrieval. In addition, the effect of LiCl-induced aversive counterconditioning could last for about 14 days. These results suggest that aversive counterconditioning during the reconsolidation of cocaine or morphine memory can prevent the re-seeking of cocaine or morphine, presumably by updating or replacing cocaine or morphine memories with aversive information.

Cytogenotoxicity effects in addicts with multidrug consumption

Drug abuse is considered a global health problem with serious social impact. In recent decades, changes in drug consumption patterns have shown a clear rising trend in the use of multiple drugs. Although the buccal micronucleus cytome (BMCyt) assay has evaluated cytotoxicity in drug abuse, there has not been an approach that takes into account this pattern of multiple drug use. Therefore, in this study, we evaluate for the first time the cytogenotoxic effects in multidrug users, and its correlation with the amount consumed and years of abuse. This study was conducted on 166 individuals by the BMCyt assay. A total of 83 individuals with a history of multiple licit (alcohol and tobacco) and at least one illicit drug abuse (marijuana, methamphetamines, cocaine, and/or inhalants), and 83 healthy individuals, non-drug abusers were analyzed. The results showed that drug abusers had higher frequencies of nuclear abnormalities nuclear buds, binucleated cells, pyknotic nuclei (PNs), karyorrhexis (KX), and abnormally condensed chromatin when compared with healthy controls. Moreover, results suggests that the use of licit and illicit drugs is related to cytogenotoxic damage, as was shown by an upward trend in the frequency of nuclear abnormalities identified in groups 1 (alcohol + tobacco + at least one illicit drug) and 2 (tobacco + at least one illicit drug). Furthermore, a positive correlation was found in the different groups, between the years and the amount of consumption of some drugs (alcohol, methamphetamine, and tobacco) with cytotoxicity markers such as KL, KX, and PNs.

Opioid Misuse and Associated Health Risks among Adults on Probation and Parole: Prevalence and Correlates 2015-2020

BACKGROUND

As state legislatures work to reduce prison populations and increase the use of community-based alternatives, limited knowledge exists about the service needs of those under criminal justice supervision in the community. Preliminary research indicates unusually high rates of disease, disability, and death. Health risks for this population include opioid misuse, a form of substance misuse that has reached epidemic proportions in the U.S. Evidence indicates this may be one of multiple epidemics this population experiences, complicating intervention.

METHODS

Our study included 5154 individuals on probation or parole. Using 2015-2020 data from the National Survey of Drug Use and Health (NSDUH), we conducted a series of logistic regressions examining associations between opioid misuse and a range of health risks, controlling for sociodemographic variables and survey year.

RESULTS

Approximately 17% of those on probation or parole indicated past-year opioid misuse, a rate 4 times higher than in the general population. Compared to those on probation and parole who did not misuse opioids, it was associated with higher odds of other health risk behaviors and mental health problems. For example, the odds of marijuana and cocaine use were 4-6 times higher and the odds of substance use disorder were 10 times higher. Similarly, the odds of experiencing major depressive episodes and serious psychological distress were 2-3 times higher.

CONCLUSIONS

Our findings reveal a markedly high risk for opioid misuse within this population along with associated risks for behavioral and mental health problems. The complex treatment needs of this population require greater policy attention and further research.

Individual-level risk factors for suicide mortality in the general population: an umbrella review

BACKGROUND

Deaths by suicide remain a major public health challenge worldwide. Identifying and targeting risk factors for suicide mortality is a potential approach to prevention. We aimed to summarise current knowledge on the range and magnitude of individual-level risk factors for suicide mortality in the general population and evaluate the quality of the evidence.

METHODS

In this umbrella review, five bibliographic databases were systematically searched for articles published from database inception to Aug 31, 2022. We included meta-analyses of observational studies on individual-level risk factors for suicide mortality in the general population. Biological, genetic, perinatal, and ecological risk factors were beyond the scope of this study. Effect sizes were synthesised and compared across domains. To test robustness and consistency of the findings, evidence for small-study effects and excess significance bias (ie, the ratio between the overall meta-analysis effect size and that of its largest included study) was examined, and prediction intervals were calculated. Risk of bias was assessed by the Risk of Bias in Systematic Reviews instrument. The protocol was pre-registered with PROSPERO (CRD42021230119).

FINDINGS

We identified 33 meta-analyses on 38 risk factors for suicide mortality in the general population. 422 (93%) of the 454 primary studies included in the meta-analyses were from high-income countries. A previous suicide attempt and suicidal ideation emerged as strong risk factors (with effect sizes ranging from 6 to 16). Psychiatric disorders were associated with a greatly elevated risk of suicide mortality, with risk ratios in the range of 4-13. Suicide risk for physical illnesses (such as cancer and epilepsy) and sociodemographic factors (including unemployment and low education) were typically increased two-fold. Contact with the criminal justice system, state care in childhood, access to firearms, and parental death by suicide also increased the risk of suicide mortality. Among risk factors for which sex-stratified analyses were available, associations were generally similar for males and females. However, the quality of the evidence was limited by excess significance and high heterogeneity, and prediction intervals suggested poor replicability for almost two-thirds of identified risk factors.

INTERPRETATION

A wide range of risk factors were identified across various domains, which underscores suicide mortality as a multifactorial phenomenon. Prevention strategies that span individual and population approaches should account for the identified factors and their relative strengths. Despite the large number of risk factors investigated, few associations were supported by robust evidence. Evidence of causal inference will need to be tested in high-quality study designs.

FUNDING

Wellcome Trust.

Cocaine and Ischemic or Hemorrhagic Stroke: A Systematic Review and Meta-Analysis of Clinical Evidence

Cocaine consumption has increased over the last decade. The potent sympathomimetic effects of the drug can lead to serious neurovascular complications in the form of ischemic stroke (IS), intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH). This systematic review and meta-analysis were designed to describe the clinical features and outcomes of patients suffering from IS, ICH, or SAH occurring in the context of cocaine use. The PubMed, Embase, Cochrane, and Web of Science libraries were queried in December 2022. Studies were included if they provided information regarding the epidemiology, clinical presentation, or outcomes in cocaine-associated strokes. Odds ratios (OR) were pooled using a random-effects model. A total of 36 papers were included. Strokes associated with cocaine use were more prevalent in younger populations and those of African American descent. Cocaine use increased the odds of IS, ICH, or SAH (OR = 5.05, p < 0.001). The odds of mortality (OR = 1.77, p = 0.0021), vasospasm (OR = 2.25, p = 0.0037), and seizures (OR = 1.61, p < 0.001) were also worse when strokes were associated with cocaine use. In addition to counseling patients on the benefits of drug cessation, clinicians should remain vigilant of the potential complications in patients who are hospitalized with cocaine-associated strokes.

Ethanol and illicit drugs acute use and abuse as risk factors for suicide: A case-control study based on forensic autopsies in the Basque Country, Spain

INTRODUCTION

Abuse/dependence and acute use of ethanol and illicit drug are considered risk factors for suicide. The risk is also influenced by demographic conditions and/or psychiatric comorbidity. The aim of the study was to test the association between presence of ethanol, illicit substances and prescribed drugs in suicide decedents and controls.

MATERIALS AND METHODS

Case-control study of autopsies performed in the Biscay Forensic Pathology Service, Basque Country, Spain from 01/01/2010 to 30/06/2021 in subjects between 15 and 55 years old. Suicide deaths (n=481) with completed autopsy were evaluated. Concurrent natural deaths were chosen as controls (n=330). The risk for suicide according to demographic, toxicological and psychiatric variables was analyzed using logistic regression.

RESULTS

Ethanol was present in 21% and illicit drugs, mainly cannabis, cocaine and amphetamine, in 27% of suicide deaths. Illicit drugs were more frequent among males. In 63% of suicide cases, prescribed psychotropic drugs were detected. In a multivariate analysis, the main risk factors for suicide were psychiatric diagnosis of illicit drug abuse/dependence (OR=5.56, 95% CI 2.74-11.30) or another mental disease as mood or psychotic disorders (OR=13.05, 95% CI 8.79-19.37). Acute presence of ethanol (OR=4.22, 95% CI 2.52-7.08), recent use of cocaine (OR=2.52, 95% CI 1.05-6.07) and age <35 years (OR=2.50, 95% CI 1.62-3.87) were also associated with suicide deaths.

CONCLUSIONS

The presence of drugs of abuse in suicide deaths of people ≤55 years old is high. Recent use of ethanol and cocaine is significantly associated with an increased suicide risk. Specific prevention strategies against exposition to substances of abuse should be promoted, especially in psychiatric patients.

Characteristics and circumstances of cocaine-related completed suicide in Australia, 2000-2021

BACKGROUND

There has been a substantial global increase in cocaine use and associated harms. The current study aimed to: 1. Determine the case characteristics and circumstances of death of cocaine-related suicide in Australia 2000-2021; and 2. Determine the toxicological profiles of cases.

METHODS

Retrospective study of cocaine-related death in Australia, 2000-2021, retrieved from the National Coronial Information System (NCIS). Suicide intent was based upon the NCIS code for "Intentional Self-harm", derived from case circumstances and coroners' conclusions. Sex comparisons were made for all major variables.

RESULTS

A total of 157 cases were identified, 82.2% male, 79.5% employed, with a mean age of 32.3 years. Concerns for mental health were documented in 65.6%, a previous suicide attempt in 21.0%, a history of substance use treatment and/or negative consequences of substance use in 45.9% and injecting drug use in 14.6%. Manner of death amongst both sexes was predominantly by physical means (82.8%). Written intent was documented in 29.3%. Intense agitation prior to the incident was noted in 28.0% and conflict in 24.8%. The median blood cocaine concentration was 0.060 mg/L (range 0.007-5.500). Other drugs were present in 95.5%, most commonly alcohol (63.1%) with a median concentration of 0.140 g/100 ml. Psychostimulants other than cocaine were present in 31.2%.

CONCLUSIONS

The 'typical' cocaine-related suicide case was a male, aged in their early thirties, who was highly likely to be employed. The majority of cases used physical means, and a substantial minority were highly agitated and engaged in conflict prior to the fatal incident.

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.

Clinical characteristics of fatal cocaine toxicity in Australia, 2000-2021

INTRODUCTION

With increased use, the number of cocaine-related deaths has increased. We aimed to determine: (i) the toxicological profile of cocaine, metabolites and adulterants amongst three groups of cocaine-related fatalities in which cocaine and/or metabolites were present in blood: (a) fatal toxicity, where cocaine only (CO) was present (n = 48), (b) multiple drug toxicity (MDT) where other drugs were present (n = 604), and (c) a comparison group of death from traumatic injury (TI, n = 232); (ii) the acute clinical presentation by group; and (iii) cardiovascular disease by group.

METHODS

Retrospective study of cocaine-related deaths in Australia, 2000-2021, from the National Coronial Information System.

RESULTS

The parent drug cocaine was significantly more common, and had a higher median concentration, amongst the CO group (97.9%, 1.550 mg/L) than the MDT (68.9%, 0.09 mg/L) and TI (70.7%, 0.05 mg/L) groups respectively. Similarly large ratios between CO, MDT and TI were seen for benzoylecgonine (2.100, 0.510, 0.240 mg/L), methylecgonine (1.350, 0.140, 0.070 mg/L), lignocaine (1.200, 0.200, 0.150 mg/L) and levamisole (0.230, 0.045, 0.025 mg/L). The two toxicity groups had significantly higher proportions than the TI group for reports of sudden collapse, seizure, acute psychosis, hyperthermia and vomiting. In addition, CO had higher proportions than MDT and TI of sudden collapse. CO had significantly higher proportions of cardiomegaly and coronary artery disease than the TI group.

DISCUSSION AND CONCLUSIONS

Compared to MDT and TI cases, CO cases had higher cocaine concentrations, higher concentrations of adulterants, higher levels of cardiovascular disease and were more likely to suddenly collapse.

Rates, characteristics and toxicology of cocaine-related deaths in Australia, 2000-2021

AIMS

To (i) assess the population mortality rates of cocaine-related deaths in Australia, 2000 to 2021; (ii) determine the circumstances of death and case characteristics; and (iii) determine their toxicological profile.

DESIGN

Retrospective study of cocaine-related deaths in Australia, 2000 to 2021, retrieved from the National Coronial Information System.

SETTING

Australia-wide.

CASES

A total of 884 cases, mean age = 33.8 (SD, 10.0) years and 86.5% (n = 765) male.

MEASUREMENTS

Information was collected on characteristics, manner of death and toxicology. Only cases in which the presence of blood cocaine and/or metabolites were included.

FINDINGS

Population rates did not significantly increase during 2001-2011 (annual percentage change [APC] = 1.5; CI, -3.2, 6.5), but from 2012, there was a marked acceleration (APC = 20.0, 95% CI, 15.5, 25.3). Circumstances of death were unintentional drug toxicity (70.7%, n = 625), intentional self-harm (17.8%, n = 157), traumatic accident (11.5%, n = 102). The proportion of cases constituted by unintentional toxicity declined across the study period (APC = -2.6; CI, -3.1, -2.1). There was a substantial decline in the proportion of cases with a history of injecting drug use (APC = -5.7; CI, -6.5, -4.9) and with a history of substance use problems (APC = -3.2; CI, -3.9, -2.5). Both cocaine (0.100 vs 0.050 mg/L, P < 0.001) and benzoylecgonine (0.590 vs 0.240 mg/L, P < 0.001) concentrations were higher amongst toxicity cases than in cases of death from traumatic injury. Cocaethylene was present in 26.4% (n = 233), levamisole in 18.6% (n = 164) and lignocaine in 11.5% (n = 102). Psychoactive drugs in addition to cocaine were present in 92.9% (n = 821), most commonly opioids (50.5%, n = 446), alcohol (47.1%, n = 416), hypnosedatives (43.2%, n = 382) and psychostimulants (30.3%, n = 268). There was a steady decline in the proportion of opioid positive cases (APC = -5.4; CI, -6.3, -4.5).

CONCLUSIONS

There was a large increase in cocaine-related deaths across Australia from 2000 to 2021. This was accompanied by changes in case profiles, with histories of injecting drug use and substance use problems, as well as recent opioid use, becoming less prominent.

All-cause and cause-specific mortality among people with severe mental illness in Brazil's public health system, 2000-15: a retrospective study

BACKGROUND

People with severe mental illness have a mortality rate higher than the general population, living an average of 10-20 years less. Most studies of mortality among people with severe mental illness have occurred in high-income countries (HICs). We aimed to estimate all-cause and cause-specific relative risk (RR) and excess mortality rate (EMR) in a nationwide cohort of inpatients with severe mental illness compared with inpatients without severe mental illness in a middle income country, Brazil.

METHODS

This national retrospective cohort study included all patients hospitalised through the Brazilian Public Health System (Sistema Único de Saúde [SUS]-Brazil) between Jan 1, 2000, and April 21, 2015. Probabilistic and deterministic record linkages integrated data from the Hospital Information System (Sistema de informações Hospitalares) and the National Mortality System (Sistema de Informação sobre Mortalidade). Follow-up duration was measured from the date of the patients' first hospitalisation until their death, or until April 21, 2015. Severe mental illness was defined as schizophrenia, bipolar disorder, or depressive disorder by ICD-10 codes used for the admission. RR and EMR were calculated with 95% CIs, comparing mortality among patients with severe mental illness with those with other diagnoses for patients aged 15 years and older. We redistributed deaths using the Global Burden of Diseases, Injuries, and Risk Factors Study methodology if ill-defined causes of death were stated as an underlying cause.

FINDINGS

From Jan 1, 2000, to April 21, 2015, 72 021 918 patients (31 510 035 [43·8%] recorded as male and 40 974 426 [56·9%] recorded as female; mean age 41·1 (SD 23·8) years) were admitted to hospital, with 749 720 patients (372 458 [49·7%] recorded as male and 378 670 [50·5%] as female) with severe mental illness. 5 102 055 patient deaths (2 862 383 [56·1%] recorded as male and 2 314 781 [45·4%] as female) and 67 485 deaths in patients with severe mental illness (39 099 [57·9%] recorded as male and 28 534 [42·3%] as female) were registered. The RR for all-cause mortality in patients with severe mental illness was 1·27 (95% CI 1·27-1·28) and the EMR was 2·52 (2·44-2·61) compared with non-psychiatric inpatients during the follow-up period. The all-cause RR was higher for females and for younger age groups; however, EMR was higher in those aged 30-59 years. The RR and EMR varied across the leading causes of death, sex, and age groups. We identified injuries (suicide, interpersonal violence, and road injuries) and cardiovascular disease (ischaemic heart disease) as having the highest EMR among those with severe mental illness. Data on ethnicity were not available.

INTERPRETATION

In contrast to studies from HICs, inpatients with severe mental illness in Brazil had high RR for idiopathic epilepsy, tuberculosis, HIV, and acute hepatitis, and no significant difference in mortality from cancer compared with inpatients without severe mental illness. These identified causes should be addressed as a priority to maximise mortality prevention among people with severe mental illness, especially in a middle-income country like Brazil that has low investment in mental health.

FUNDING

Bill and Melinda Gates Foundation, Fundação de Amparo a Pesquisa do Estado de Minas Gerais, FAPEMIG, and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil.

Strengthened and posterior-shifted structural rich-club organization in people who use cocaine

BACKGROUND

People with cocaine use disorder (CUD) often have abnormal cognitive function and brain structure. Cognition is supported by brain networks that typically have characteristics like rich-club organization, which is a group of regions that are highly connected across the brain and to each other, and small worldness, which is a balance between local and long-distance connections. However, it is unknown whether there are abnormalities in structural brain network connectivity of CUD.

METHODS

Using diffusion-weighted imaging, we measured structural connectivity in 37 people with CUD and 38 age-matched controls. We identified differences in rich-club organization and whether such differences related to small worldness and behavior. We also tested whether rich-club reorganization was associated with caudate and putamen structural connectivity due to the relevance of the dopamine system to cocaine use.

RESULTS

People with CUD had a higher normalized rich-club coefficient than controls, more edges connecting rich-club nodes to each other and to non-rich-club nodes, and fewer edges connecting non-rich-club nodes. Rich-club nodes were shifted posterior and lateral. Rich-club reorganization was related to lower clustered connectivity around individual nodes found in CUD, to increased impulsivity, and to a decrease in caudate connectivity.

CONCLUSIONS

These findings are consistent with previous work showing increased rich-club connectivity in conditions associated with a hypofunctional dopamine system. The posterior shift in rich-club nodes in CUD suggests that the structural connectivity of posterior regions may be more impacted than previously recognized in models based on brain function and morphology.

The impact of behavioural risk factors on communicable diseases: a systematic review of reviews

Background

The coronavirus (COVID-19) pandemic has highlighted that individuals with behavioural risk factors commonly associated with non-communicable diseases (NCDs), such as smoking, harmful alcohol use, obesity, and physical inactivity, are more likely to experience severe symptoms from COVID-19. These risk factors have been shown to increase the risk of NCDs, but less is known about their broader influence on communicable diseases. Taking a wide focus on a range of common communicable diseases, this review aimed to synthesise research examining the impact of behavioural risk factors commonly associated with NCDs on risks of contracting, or having more severe outcomes from, communicable diseases.

Methods

Literature searches identified systematic reviews and meta-analyses that examined the association between behavioural risk factors (alcohol, smoking, illicit drug use, physical inactivity, obesity and poor diet) and the contraction/severity of common communicable diseases, including infection or associated pathogens. An a priori, prospectively registered protocol was followed (PROSPERO; registration number CRD42020223890).

Results

Fifty-three systematic reviews were included, of which 36 were also meta-analyses. Reviews focused on: tuberculosis, human immunodeficiency virus, hepatitis C virus, hepatitis B virus, invasive bacterial diseases, pneumonia, influenza, and COVID-19. Twenty-one reviews examined the association between behavioural risk factors and communicable disease contraction and 35 examined their association with communicable disease outcomes (three examined their association with both contraction and outcomes). Fifty out of 53 reviews (94%) concluded that at least one of the behavioural risk factors studied increased the risk of contracting or experiencing worse health outcomes from a communicable disease. Across all reviews, effect sizes, where calculated, ranged from 0.83 to 8.22.

Conclusions

Behavioural risk factors play a significant role in the risk of contracting and experiencing more severe outcomes from communicable diseases. Prevention of communicable diseases is likely to be most successful if it involves the prevention of behavioural risk factors commonly associated with NCDs. These findings are important for understanding risks associated with communicable disease, and timely, given the COVID-19 pandemic and the need for improvements in future pandemic preparedness. Addressing behavioural risk factors should be an important part of work to build resilience against any emerging and future epidemics and pandemics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12148-y.

Population-Based Study on the All-Cause and Cause-Specific Risks of Mortality among Long-Term Opioid Analgesics Users without Cancer in Taiwan

(1) Background: The prevalence of opioid use in Taiwan increased by 41% between 2002 and 2014. However, little is known regarding the risk of mortality among long-term opioid analgesics users who do not have cancer. This study investigated this mortality risk with an emphasis on the calendar year and patients’ age and sex. (2) Methods: This retrospective cohort study included 12,990 adult individuals without cancer who were long-term users of opioid analgesics and were randomly selected from the data set of Taiwan’s National Health Insurance program from 2000 to 2012. They were then followed up through 2013. Information on the underlying causes of death was retrieved from the Taiwan Death Registry. Age, sex, and calendar year-standardized mortality ratios (SMRs) of all-cause and cause-specific mortality were calculated with reference to those of the general population. (3) Results: With up to 14 years of follow-up, 558 individuals had all-cause mortality in 48,020 person-years (cumulative mortality: 4.3%, mortality rate: 11.62 per 1000 person-years). Compared with the general population, the all-cause SMR of 4.30 (95% confidence interval (95% CI): 3.95–4.66) was significantly higher: it was higher in men than in women, declined with calendar year and age, and was significantly higher for both natural (4.15, 95% CI: 3.78–4.53) and unnatural (5.04, 95% CI: 3.88–6.45) causes. (4) Conclusions: Long-term opioid analgesics use among individuals without cancer in Taiwan was associated with a significantly increased risk of mortality. The notably increased mortality in younger adults warrants attention. Strategies to reduce long-term opioid analgesics use, especially their overuse or misuse, are in an urgent need.

The role of mitochondria in cocaine addiction

The incidence of cocaine abuse is increasing especially in the U.K. where the rates are among the highest in Europe. In addition to its role as a psychostimulant, cocaine has profound effect on brain metabolism, impacting glycolysis and impairing oxidative phosphorylation. Cocaine exposure alters metabolic gene expression and protein networks in brain regions including the prefrontal cortex, the ventral tegmental area and the nucleus accumbens, the principal nuclei of the brain reward system. Here, we focus on how cocaine impacts mitochondrial function, in particular through alterations in electron transport chain function, reactive oxygen species (ROS) production and oxidative stress (OS), mitochondrial dynamics and mitophagy. Finally, we describe the impact of cocaine on brain energy metabolism in the developing brain following prenatal exposure. The plethora of mitochondrial functions altered following cocaine exposure suggest that therapies maintaining mitochondrial functional integrity may hold promise in mitigating cocaine pathology and addiction.