Michael Lynskey

Michael Lynskey
King's College London | KCL · Department of Addictions

About

447
Publications
88,623
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32,428
Citations
Additional affiliations
January 2013 - present
King's College London
Position
  • Professor (Full)

Publications

Publications (447)
Article
Full-text available
Background: Among adolescents, cannabis use is a health concern due to associations with drug addiction and mental health disorders across the life course. It has been shown that childhood maltreatment is associated with drug addiction in adulthood. However, a better understanding of the relationship between maltreatment and drug use may improve ta...
Preprint
Background. Drug classes are grouped based on their chemical and pharmacological properties, but prescription and illicit drugs differ in other important ways. Opioid and stimulant classes contain prescription and illicit forms differentially associated with salient risk factors (common route of administration, legality), making them useful compara...
Article
Full-text available
Aims This study compared prevalence and hospital use among individuals frequently admitted to hospital in England with wholly attributable alcohol‐related diagnoses (WAAD), known as alcohol related frequent attenders (ARFAs), with those of non‐alcohol frequent attenders (NAFAs), non‐frequent alcohol attenders (ARNFAs) and non‐alcohol non‐frequent a...
Preprint
Individuals with a gambling disorder are more likely to engage in suicidal behaviors, but it is not yet clear whether this is due to common etiologic factors or to gambling disorder being causally related to suicidality. In a large national community-based twin sample, the temporal relation and the underlying causes of the association between gambl...
Article
This review summarizes evidence on the effects of cannabis use on the development of adolescents and young adults. It draws on epidemiological studies, neuroimaging studies, case-control studies, and twin and Mendelian randomization studies. The acute risks include psychiatric symptoms associated with the use of high THC (tetrahydrocannabinol) prod...
Article
The sale of cannabis for adult recreational use has been made legal in nine US states since 2012, and nationally in Uruguay in 2013 and Canada in 2018. We review US research on the effects of legalization on cannabis use among adults and adolescents and on cannabis‐related harms; the impact of legalizing adult recreational use on cannabis price, av...
Article
Background First episode psychosis (FEP) patients who use cannabis experience more frequent psychotic and euphoric intoxication experiences compared to controls. It is not clear whether this is consequent to patients being more vulnerable to the effects of cannabis use or to their heavier pattern of use. We aimed to determine whether extent of use...
Article
Background: People who inject drugs (PWID) are at elevated risk of HIV infection. Data on population sizes of PWID living with HIV are needed to inform the implementation of prevention, treatment and care programs. We estimated national population sizes of people who recently (past 12 months) injected drugs living with HIV and evaluated ecological...
Article
Full-text available
Background: Globally, an estimated 15·6 million people inject drugs. We aimed to investigate global variation in the age profile of people who inject drugs (PWID), identify country-level factors associated with age of PWID, and assess the association between injecting drug use (IDU) in young people and rates of injecting and sexual risk behaviours...
Preprint
Full-text available
Background: Some recent studies have challenged the direction of causality for the association between cannabis use and psychotic disorder, suggesting that cannabis use initiation is explained by common genetic variants associated with risk of schizophrenia. We used data from the European Union Gene-Environment Interaction consortium (EUGEI) case-c...
Article
We assess the current and describe possible future public health impacts of the legalisation of cannabis production, sale, and use in the Americas. First, we describe global patterns of cannabis use and their most probable adverse health effects. Second, we summarise evidence regarding the effectiveness of cannabinoids for medicinal use and describ...
Preprint
Full-text available
Aims First Episode Psychosis (FEP) patients who use cannabis experience more frequent psychotic and euphoric intoxication experiences compared to controls. It is not clear whether this is consequent to patients being more vulnerable to the effects of cannabis use or to their heavier pattern of use. We aimed to determine whether extent of use predic...
Article
Full-text available
Background: Rumination is a cognitive process that is implicated in the development and maintenance of various forms of psychopathology, including problematic substance use. Most studies on the role of rumination in substance use have been conducted among community samples or individuals with alcohol use disorders and have predominately focused on...
Article
Psychotic patients with a lifetime history of cannabis use generally show better cognitive functioning than other psychotic patients. Some authors suggest that cannabis-using patients may have been less cognitively impaired and less socially withdrawn in their premorbid life. Using a dataset comprising 948 patients with first-episode psychosis (FEP...
Article
Background FEP patients who use cannabis experience more frequent intoxication experiences compared to controls. It is not clear whether this is consequent to patients being more vulnerable to the effects of cannabis use or to their heavier pattern of use. We aimed to determine whether extent of use predicted psychotic-like and euphoric intoxicatio...
Article
Full-text available
Background: Cannabis use is associated with increased risk of later psychotic disorder but whether it affects incidence of the disorder remains unclear. We aimed to identify patterns of cannabis use with the strongest effect on odds of psychotic disorder across Europe and explore whether differences in such patterns contribute to variations in the...
Article
Background: Women-specific factors exist that increases vulnerability to drug-related harms from injecting drug use including bloodborne viruses (BBV), but gender differences in BBV prevalence have not been systematically examined. Methods: We conducted meta-analyses to estimate country, regional, and global prevalence of serologically-confirmed...
Article
Preceding initiation, opportunity to use heroin is the earliest necessary condition for heroin-related outcomes to occur. This study aimed to characterise first heroin use opportunity (prior to initiation) and to identify heroin-related outcomes associated with earlier age at first opportunity. Structured interviews were conducted with 93 opiate su...
Article
Background and Aims People who have recently injected drugs are a priority population in efforts to achieve hepatitis C virus (HCV) elimination. This study estimated the prevalence and number of people with recent injecting drug use living with HCV, and the proportion of people with recent injecting drug use among all people living with HCV infecti...
Article
Background: Cannabis is the second most commonly used substance after alcohol among people seeking treatment for other drug use, but no statistics are available regarding secondary cannabis use among drug treatment clients. Objectives: To investigate levels of secondary cannabis use among drug treatment clients and perceived need for support addre...
Poster
The poster presents findings from survey of clients from four London drug and alcohol treatment centers. It investigates the level of secondary cannabis use among treatment clients and their perceived need for and availability of support for problem cannabis use.
Article
The present study examined the phenotypic, genetic, and environmental correlations between four humor styles (affiliative, self-enhancing, aggressive, and self-defeating) and loneliness in Australian adult twins. At the phenotypic level, the two adaptive humor style dimensions (affiliative and self-enhancing) were found to correlate negatively with...
Article
Full-text available
Background: People who inject drugs (PWID) are a key population affected by the global HIV and hepatitis C virus (HCV) epidemics. HIV and HCV prevention interventions for PWID include needle and syringe programmes (NSP), opioid substitution therapy (OST), HIV counselling and testing, HIV antiretroviral therapy (ART), and condom distribution progra...
Article
Full-text available
Background: Sharing of equipment used for injecting drug use (IDU) is a substantial cause of disease burden and a contributor to blood-borne virus transmission. We did a global multistage systematic review to identify the prevalence of IDU among people aged 15-64 years; sociodemographic characteristics of and risk factors for people who inject dru...
Article
Objective: Few studies linking single motherhood and maternal smoking during pregnancy consider correlated risk from problem substance use beyond history of smoking and concurrent use of alcohol. In the present study, we used propensity score methods to examine whether the risk of smoking during pregnancy associated with single motherhood is the r...
Article
Neuroticism, a ‘Big Five’ personality trait, has been associated with sub-clinical traits of both autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). The objective of the current study was to examine whether causal overlap between ASD and ADHD traits can be accounted for by genetic and environmental risk factors that...
Article
Full-text available
Introduction Harmful alcohol consumption, particularly alcohol use disorder (AUD), is a worldwide health priority, contributing substantially to global morbidity and mortality. The peak age of onset of AUD is 18–24, thus a deeper understanding of the young adult experience is vital if we are to identify modifiable risk factors and intervene early i...
Article
Full-text available
Cannabis use disorder (CUD) co-occurs with major depressive disorder (MDD) more frequently than would be expected by chance. However, studies to date have not produced a clear understanding of the mechanisms underlying this co-morbidity. Genetically informative studies can add valuable insight to this problem, as they allow the evaluation of compet...
Article
Full-text available
Background: Early and frequent cannabis use are associated with an increased likelihood of major depressive disorder (MDD) as well as suicidal thoughts and behaviours. We identify associations between aspects of cannabis use, MDD, and suicidal thoughts and behaviours and examine whether such associations persist after accounting for those predispo...
Article
Introduction and aims: The effect of heroin administration route on speed of transition to regular use is unknown. This paper aims to determine whether the speed of transition from initiation of heroin use to daily heroin use differs by route of administration (injecting, chasing/inhaling or snorting). Design and methods: Privileged access inter...
Article
Increasing mortality and morbidity associated with opioid analgesics has led to concerns about their misuse and abuse, even when obtained via a prescription. These concerns have been most pronounced in the United States of America (USA), but limited data make it difficult to determine whether it is a problem in other countries. We investigated opio...
Article
Background: The risk of individuals having adverse effects from drug use (eg, alcohol, tobacco) generally depends on the frequency of use and potency of the drug used. The risk of individuals having a psychotic disorder showed a roughly 3 times increase in users of skunk-like/high potency cannabis and over 5 times in daily users of high potency can...
Article
Full-text available
Background: Substance use and misuse and suicidal thoughts and behaviors tend to co-occur. The purpose of this study was to examine whether (a) suicidal ideation and attempt are related to onset of alcohol, nicotine and cannabis use and dependence; (b) early use of alcohol, nicotine and cannabis is associated with onset of suicidal ideation and at...
Article
Background Excess alcohol consumption is a growing public health problem, causing 5·3% of deaths worldwide in those aged under 60 years. In the UK, alcohol use costs the National Health Service (NHS) £3·5 billion annually, 80% of which is used for hospital-based care. Alcohol-related hospital admissions have doubled in the past 8 years in England....
Article
Sensation seeking and impulsivity are personality traits that are correlated with risk for antisocial behavior (ASB). This paper uses two independent samples of twins to (a) test the extent to which sensation seeking and impulsivity statistically mediate genetic influence on ASB, and (b) compare this to genetic influences accounted for by other per...
Article
Aims: To identify trajectories of heroin use in Australia, predictors of trajectory group membership, and subsequent outcomes, among people with heroin dependence over 10-11-years. Design: Longitudinal cohort study. Setting: Sydney, Australia. Participants: 615 participants were recruited between 2001-2002 as part of the Australian Treatment...
Article
Full-text available
Objective: Cannabis use, particularly at an early age, has been linked to suicidal thoughts and behavior, but minimal work has examined the association between cannabis use and lifetime nonsuicidal self-injury (NSSI). The current study aims to characterize the overlap between lifetime and early cannabis use and NSSI and to examine genetic and envi...
Article
Background and aims: Since 2012 four US states have legalized the retail sale of cannabis for recreational use by adults, and more are likely to follow. This report aimed to (1) briefly describe the regulatory regimes so far implemented; (2) outline their plausible effects on cannabis use and cannabis-related harm; and (3) suggest what research is...
Article
The present study examined the phenotypic, genetic, and environmental correlations between four humor styles (affiliative, self-enhancing, aggressive, and self-defeating) and four dimensions of borderline personality disorder (affective instability, identity disturbance, negative relationships, self-harm) as well as a total borderline personality d...
Article
Behavioral genetic studies have provided insights into why early substance use initiation is associated with increased risk for disorder. Few genetically informative studies, however, have operationalized initiation as the of first use and simultaneously modeled the timing of initiation and problematic use of multiple substances. Such research can...
Article
Full-text available
Cannabis and tobacco are common drugs of abuse worldwide and are often used in combination through various routes of administration (ROAs). Here, we aimed to provide an overview of how cannabis and tobacco routes varied across countries and assess the impact of tobacco-based ROAs on motivation to use less cannabis, and less tobacco, in different mo...
Article
Full-text available
Despite evidence of substantial comorbidity between psychiatric disorders and substance involvement, the extent to which common genetic factors contribute to their co-occurrence remains understudied. In the current study, we tested for associations between polygenic risk for psychiatric disorders and substance involvement (i.e., ranging from ever-u...
Article
Full-text available
The current study examined a stage-based alcohol use trajectory model to test for potential causal effects of earlier drinking milestones on later drinking milestones in a combined sample of two cohorts of Australian monozygotic and same-sex dizygotic twins (N = 7,398, age M = 30.46, SD = 2.61, 61% male, 56% monozygotic twins). Ages of drinking, dr...
Article
Background and aims: Substance use has been implicated in the onset and maintenance of risky sexual behaviors, which have particularly devastating consequences in young women. This study examined whether (i) adolescent onset of cannabis use is associated with repeated voluntary unprotected sex in women and (ii) whether this association persists af...
Article
The citizens of four US states—Alaska, Colorado, Oregon, and Washington—have voted to legalise the sale of cannabis to adults for recreational purposes, and more states look likely to follow. Experience with alcohol and tobacco suggests that a for-profit legal cannabis industry will increase use by making cannabis more socially acceptable to use, m...
Article
Commentary to: Considering marijuana legalization carefully: insights for other jurisdictions from analysis for Vermont
Article
Full-text available
Despite well-known adverse health effects of maternal smoking during pregnancy (MSP), it is still unclear if MSP varies geographically and if neighborhood socioeconomic deprivation (SED) plays an important role in MSP. This study aims to investigate small-area geographic variation in MSP and examine the association of SED with MSP.The Missouri Adol...
Article
Full-text available
Background: Use of cigarettes and cannabis frequently co-occurs. We examine the role of genetic and environmental influences on variation in and covariation between tobacco cigarette and cannabis use across European-American (EA) and African-American (AA) women. Methods: Data on lifetime cannabis and cigarette use were drawn from interviews of 9...
Article
Aims: This study examines the type of alcohol-related problems that commonly occur before the onset of depressive experiences to shed light on the mechanisms underlying the alcohol-depression comorbidity relationship. Methods: Data were from the 1992 USA National Longitudinal Alcohol Epidemiologic Survey. Analytical sample comprised of drinkers...
Article
Full-text available
The mu1 opioid receptor gene, OPRM1, has long been a high-priority candidate for human genetic studies of addiction. Because of its potential functional significance, the non-synonymous variant rs1799971 (A118G, Asn40Asp) in OPRM1 has been extensively studied, yet its role in addiction has remained unclear, with conflicting association findings. To...
Article
We did a systematic review of reviews with evidence on the effectiveness of prevention, early intervention, harm reduction, and treatment of problem use in young people for tobacco, alcohol, and illicit drugs (eg, cannabis, opioids, amphetamines, or cocaine). Taxation, public consumption bans, advertising restrictions, and minimum legal age are eff...
Article
During the last 20 years, there have been substantial changes in the legal status and public perception of marijuana in the United States. Decriminalization, medical dispensaries with marijuana for those with a physician’s note, and legalization of marijuana in several states have resulted in increased availability and more relaxed views toward mar...
Article
Substance use in young people (aged 10-24 years) might disrupt key periods of transition that occur as the adolescent brain undergoes cognitive and emotional development, and key psychosocial transitions are made. Adolescence is the peak time for initiation of substance use, with tobacco and alcohol usually preceding the use of illicit drugs. Subst...
Article
During puberty, when young people are completing their education, transitioning into employment, and forming longer-term intimate relationships, a shift in emotional regulation and an increase in risky behaviour, including substance use, is seen. This Series paper considers the potential effects of alcohol, tobacco, and illicit drug use during this...
Article
Introduction: Forms of childhood trauma tend to co-occur and are associated with increased risk for psychiatric and substance use disorders. Commonly used binary measures of trauma exposure have substantial limitations. Methods: We performed multigroup confirmatory factor analysis (CFA), separately by sex, using data from the Childhood Trauma (C...
Data
Data S1. Supplementary Methods. Figure S1. Factor model showing the three first‐order factors (CSA, CPA, and PPA) and one second‐order factor (CTF) developed in CT Study data. Table S1. Prevalence (%) of factor component items by gender in the three samples. Table S2. Factor loadings (SE) by gender in the CT Study and CAT Study samples. Table S...
Article
Full-text available
Background: Many studies have reported that cannabis use increases the risk of a first episode of psychosis (FEP). However, only a few studies have investigated the nature of cannabis-related experiences in FEP patients, and none has examined whether these experiences are similar in FEP and general populations. The aim of this study was to explore...
Article
The present study examined the phenotypic, genetic, and environmental correlations between four humor styles (affiliative, self-enhancing, aggressive, and self-defeating) and four dimensions of borderline personality disorder (affective instability, identity disturbance, negative relationships, self-harm) as well as a total borderline personality d...
Article
Full-text available
Cannabis;co-administration;harm reduction;marijuana;nicotine;route of administration;tobacco;vaping;vaporizer
Article
Despite evidence for heritable variation in cannabis involvement and the discovery of cannabinoid receptors and their endogenous ligands, no consistent patterns have emerged from candidate endocannabinoid (eCB) genetic association studies of cannabis involvement. Given interactions between eCB and stress systems and associations between childhood s...
Article
Background: Self-harm has considerable societal and economic costs and has been extensively studied in relation to alcohol involvement. Although early onset alcohol use (EAU) has been causally linked to maladaptive clinical outcomes, its association with self-harm is less well characterized. This study aimed to further examine the link between EAU...
Article
Childhood maltreatment (CM) has consistently been linked with adverse outcomes including substance use disorders and adult sexual revictimization. Adult sexual victimization itself has been linked with psychopathology but has predominately been studied in women. The current investigation examines the impact of CM and co-occurring psychopathology on...
Article
Prior neuroimaging studies have suggested that alterations in brain structure may be a consequence of cannabis use. Siblings discordant for cannabis use offer an opportunity to use cross-sectional data to disentangle such causal hypotheses from shared effects of genetics and familial environment on brain structure and cannabis use. To determine whe...
Article
Genetic influences contribute significantly to co-morbidity between conduct disorder and substance use disorders. Estimating the extent of overlap can assist in the development of phenotypes for genomic analyses. Multivariate quantitative genetic analyses were conducted using data from 9577 individuals, including 3982 complete twin pairs and 1613 i...