Medical cannabis and mental health: A guided systematic review

doi:10.1016/j.cpr.2016.10.002

Clinical Psychology Review

Volume 51, February 2017, Pages 15-29

https://doi.org/10.1016/j.cpr.2016.10.002 Get rights and content

Highlights

•
Mental health conditions are prominent among the reasons for medical cannabis use.
•
Cannabis has potential for the treatment of PTSD and substance use disorders.
•
Cannabis use may influence cognitive assessment, particularly with regard to memory.
•
Cannabis use does not appear to increase risk of harm to self or others.
•
More research is needed to characterize the mental health impact of medical cannabis.

Abstract

This review considers the potential influences of the use of cannabis for therapeutic purposes (CTP) on areas of interest to mental health professionals, with foci on adult psychopathology and assessment. We identified 31 articles relating to the use of CTP and mental health, and 29 review articles on cannabis use and mental health that did not focus on use for therapeutic purposes. Results reflect the prominence of mental health conditions among the reasons for CTP use, and the relative dearth of high-quality evidence related to CTP in this context, thereby highlighting the need for further research into the harms and benefits of medical cannabis relative to other therapeutic options. Preliminary evidence suggests that CTP may have potential for the treatment of PTSD, and as a substitute for problematic use of other substances. Extrapolation from reviews of non-therapeutic cannabis use suggests that the use of CTP may be problematic among individuals with psychotic disorders. The clinical implications of CTP use among individuals with mood disorders are unclear. With regard to assessment, evidence suggests that CTP use does not increase risk of harm to self or others. Acute cannabis intoxication and recent CTP use may result in reversible deficits with the potential to influence cognitive assessment, particularly on tests of short-term memory.

Section snippets

Background

The first decades of the 21st century have witnessed a dramatic resurgence of interest in the therapeutic potential of cannabis. In response, a growing number of countries and jurisdictions have initiated or expanded programs to allow legal access to cannabis for therapeutic purposes (CTP). Although the majority of CTP programs specifically focus on the use of cannabis for symptoms associated with physical health disorders (e.g. arthritis, cancer, chronic pain; see Belendiuk, Baldini, &

Methodology

To systematically review research elucidating the influence of CTP use on adult psychopathology and psychological assessment, we comprehensively review studies of CTP and meta-review studies of NMC. Throughout, we adopt an integrative approach that allows for review of diverse methodologies including longitudinal, cross-sectional, and lab-based studies (Whittemore & Knafl, 2005). The review is organized as mini-reviews of areas of interface between CTP and clinical practice, with discussion of

Results

Our CTP search identified 31 studies, with a total of 23,850 participants. Of these studies 87% (27) were cross-sectional and 68% (21) were US samples. Recruitment from medical cannabis dispensaries was the most frequent method of data collection (42% (13)), followed by recruitment from clinics that specialize in disorders for which CPT use is prominent (e.g. pain, M.S.) (19% (6)), and reviews of records from clinics that focus on providing assessments for eligibility to access CTP (19% (6)).

Summary

The reemergence of the therapeutic use of cannabis leads to several points of interface with domains related to clinical psychology and other mental health professions. Our review focused on what we feel are the most central areas in which CTP presents an issue of interest to clinical judgment or practice; implications for clinical disorders of adulthood (i.e. DSM-V, Axis I), assessment of cognitive functioning, and of risk of harm to self and others. The literature on CTP and mental health is

Conflict of interest

Zach Walsh is Coordinating Principal Investigator on a clinical trial of cannabis that is sponsored by Tilray, a licensed producer of medical cannabis. Kim Crosby and Michelle Thiessen are paid by Tilray as graduate research assistants to Dr. Walsh in running that trial. Marcel Bonn-Miller has been a paid consultant for CW Botanicals, Tilray, and Aphria within the past 12 months, all of whom are producers of medical cannabis. Within the past 12 months, he has also served as a consultant for

Contributors

Zach Walsh designed and initiated the review, and wrote the first draft. Raul Gonzalez wrote portions of the first draft and provided several editorial reviews of the manuscript. Kim Crosby and Chris Carroll conducted literature searches, provided summaries of previous research studies and contributed to the writing of the first draft. Michelle Thiessen and Kim Crosby conducted literature searches and rated the studies for quality. Marcel Bonn-Miller provided several editorial reviews of the

Acknowledgement

Preparation of this manuscript was supported in part by a grant to Zach Walsh from the Social Sciences and Humanities Research Council of Canada. The expressed views do not necessarily represent those of the Social Sciences and Humanities Research Council of Canada or of the U.S. Department of Veterans Affairs.

References (206)

A. Agrawal et al.
Cannabis involvement in individuals with bipolar disorder
Psychiatry Research
(2011)
L. Ashrafioun et al.
Characteristics of substance use disorder treatment patients using medical cannabis for pain
Addictive Behaviors
(2015)
N. Bally et al.
Cannabis use and first manic episode
Journal of Affective Disorders
(2014)
L. Belle-Isle et al.
Barrier to access for Canadians who use cannabis for therapeutic purposes
The International Journal on Drug Policy
(2014)
M.T. Boden et al.
The interactive effects of emotional clarity and cognitive reappraisal on problematic cannabis use among medical cannabis users
Addictive Behaviors
(2013)
K.M. Bohnert et al.
Positive posttraumatic stress disorder screens among first-time medical cannabis patients: Prevalence and association with other substance use
Addictive Behaviors
(2014)
M.O. Bonn-Miller et al.
Using cannabis to help you sleep: Heightened frequency of medical cannabis use among those with PTSD
Drug and Alcohol Dependence
(2014)
C.J. Boyd et al.
Adolescents’ use of medical marijuana: A secondary analysis of Monitoring the Future data
Journal of Adolescent Health
(2015)
R.J. Braga et al.
Cognitive and clinical outcomes associated with cannabis use in patients with bipolar I disorder
Psychiatry Research
(2012)
J.D. Buckner et al.
Marijuana effect expectancies: Relations to social anxiety and marijuana use problems
Addictive Behaviors
(2008)

J.D. Buckner et al.

Peer influence and gender differences in problematic cannabis use among individuals with social anxiety

Journal of Anxiety Disorders

(2006)

J.D. Buckner et al.

Social anxiety and problematic cannabis use: Evaluating the moderating role of stress reactivity and perceived coping

Behaviour Research and Therapy

(2006)

J.D. Buckner et al.

Marijuana use motives and social anxiety among marijuana-using young adults

Addictive Behaviors

(2007)

J.D. Buckner et al.

Specificity of social anxiety disorder as a risk factor for alcohol and cannabis dependence

Journal of Psychiatric Research

(2008)

J.D. Buckner et al.

The relationship between cannabis use disorders and social anxiety disorder in the National Epidemiological Study of Alcohol and Related Conditions (NESARC)

Drug and Alcohol Dependence

(2012)

J.D. Buckner et al.

Cannabis-related impairment and social anxiety: The roles of gender and cannabis use motives

Addictive Behaviors

(2012)

K.E. Cairns et al.

Risk and protective factors for depression that adolescents can modify: A systematic review and meta-analysis of longitudinal studies

Journal of Affective Disorders

(2014)

G. Carrà et al.

Attempted suicide in people with co-occurring bipolar and substance use disorders: Systematic review and meta-analysis

Journal of Affective Disorders

(2014)

H. Chabrol et al.

Cannabis use and suicidal behaviors in high-school students

Addictive Behaviors

(2008)

L. Degenhardt et al.

Evaluating the drug use “gateway” theory using cross-national data

Drug and Alcohol Dependence

(2010)

T.F. Denson et al.

Decreased depression in marijuana users

Addictive Behaviors

(2006)

D.C. D'Souza et al.

Delta-9-tetrahydrocannabinol effects in schizophrenia: Implications for cognition, psychosis, & addiction

Biological Psychiatry

(2005)

M. Gibbs et al.

Cannabis use and mania symptoms: A systematic review and meta-analysis

Journal of Affective Disorders

(2015)

C.L. Hart et al.

Effects of acute smoked marijuana on cognitive performance

Neuropsychopharmacology

(2001)

M.R. Hayatbakhsh et al.

Cannabis and anxiety and depression in young adults: A large prospective study

Journal of the American Academy of Child and Adolescent Psychiatry

(2007)

K.P. Hill et al.

Association of cannabis use with opioid outcomes among opioid-dependent youth

Drug and Alcohol Dependence

(2013)

P.N. Hoaken et al.

Drugs of abuse and the elicitation of human aggressive behavior

Addictive Behaviors

(2003)

M.A. Ilgen et al.

Characteristics of adults seeking medical marijuana certification

Drug and Alcohol Dependence

(2013)

T.A. Iseger et al.

A systematic review of the antipsychotic properties of cannabidiol in humans

Schizophrenia Research

(2015)

E.L. Abel

The relationship between cannabis and violence: A review

Psychological Bulletin

(1977)

S.K. Aggarwal et al.

Prospectively surveying health-related quality of life and symptom relief in a lot-based sample of medical cannabis-using patients in urban Washington state reveals managed chronic illness and debility

American Journal of Hospice & Palliative Medicine

(2012)

J. Alfonso et al.

Differences in the marijuana expectancies of adolescents in relation to marijuana use

Substance Use & Misuse

(2007)

American Psychiatric Association

Diagnostic and statistical manual of mental disorders

(2000)

American Psychiatric Association

Diagnostic and statistical manual of mental disorders

(2013)

D.M. Anderson et al.

Medical marijuana laws, traffic fatalities, and alcohol consumption

Journal of Law and Economics

(2013)

D.M. Anderson et al.

Medical marijuana laws and suicides by gender and age

American Journal of Public Health

(2014)

M. Arendt et al.

Testing the self-medication hypothesis of depression and aggression in cannabis-dependent subjects

Psychological Medicine

(2007)

L. Arseneault et al.

Mental disorders and violence in a total birth cohort: Results from the Dunedin study

Archives of General Psychiatry

(2000)

C.H. Ashton et al.

Cannabinoids in bipolar affective disorder: A review and discussion of their therapeutic potential

Journal of Psychopharmacology

(2005)

K.A. Babson et al.

Sleep disturbances: Implications for cannabis use, cannabis use cessation, and cannabis use treatment

Current Addiction Reports

(2014)

K.A. Babson et al.

Sleep quality moderates the relation between depression symptoms and problematic cannabis use among medical cannabis users

The American Journal of Drug and Alcohol Abuse

(2013)

M.A. Bachhuber et al.

Medical cannabis laws and opioid analgesic overdose mortality in the United States, 1999–2010

JAMA Internal Medicine

(2014)

L. Barcella

Secret “sober” pot smokers

A.L. Beautrais et al.

Cannabis abuse and serious suicide attempts

Addiction

(1999)

G. Bedi et al.

Efficacy and tolerability of high-dose dronabinol maintenance in HIV-positive marijuana smokers: A controlled laboratory study

Psychopharmacology

(2010)

K.A. Belendiuk et al.

Narrative review of the safety and efficacy of marijuana for the treatment of commonly state-approved medical and psychiatric disorders

Addiction Science and Practice

(2015)

M.M. Bergamaschi et al.

Cannabidiol reduces the anxiety induced by simulated public speaking in treatment-naive social phobia patients

Neuropsychopharmacology

(2011)

M.A.P. Bloomfield et al.

The link between dopamine function and apathy in cannabis users: An [¹⁸F]-DOPA PET imaging study

Psychopharmacology

(2014)

M.T. Boden et al.

Posttraumatic stress disorder and cannabis use characteristics among military veterans with cannabis dependence

The American Journal on Addictions

(2013)

M.O. Bonn-Miller et al.

Prevalence of cannabis use disorder diagnoses among veterans in 2002, 2008, and 2009

Psychological Services

(2012)

Cited by (174)

Do trauma cue exposure and/or PTSD symptom severity intensify selective approach bias toward cannabis cues in regular cannabis users with trauma histories?
2023, Behaviour Research and Therapy
Trauma cue-elicited activation of automatic cannabis-related cognitive biases are theorized to contribute to comorbid posttraumatic stress disorder and cannabis use disorder. This phenomenon can be studied experimentally by combining the trauma cue reactivity paradigm (CRP) with cannabis-related cognitive processing tasks. In this study, we used a computerized cannabis approach-avoidance task (AAT) to assess automatic cannabis (vs. neutral) approach bias following personalized trauma (vs. neutral) CRP exposure. We hypothesized that selective cannabis (vs. neutral) approach biases on the AAT would be larger among participants with higher PTSD symptom severity, particularly following trauma (vs. neutral) cue exposure. We used a within-subjects experimental design with a continuous between-subjects moderator (PTSD symptom severity). Participants were exposed to both a trauma and neutral CRP in random order, completing a cannabis AAT (cannabis vs. neutral stimuli) following each cue exposure. Current cannabis users with histories of psychological trauma (n = 50; 34% male; mean age = 37.8 years) described their most traumatic lifetime event, and a similarly-detailed neutral event, according to an established interview protocol that served as the CRP. As hypothesized, an AAT stimulus type x PTSD symptom severity interaction emerged (p = .042) with approach bias greater to cannabis than neutral stimuli for participants with higher (p = .006), but not lower (p = .36), PTSD symptom severity. Contrasting expectations, the stimulus type x PTSD symptoms effect was not intensified by trauma cue exposure (p = .19). Selective cannabis approach bias may be chronically activated in cannabis users with higher PTSD symptom severity and may serve as an automatic cognitive mechanism to help explain PTSD-CUD co-morbidity.
Psychedelics and Related Pharmacotherapies as Integrative Medicine for Older Adults in Palliative Care
2023, Clinics in Geriatric Medicine
Phytochemical interventions for post-traumatic stress disorder: A cluster co-occurrence network analysis using CiteSpace
2023, Journal of Integrative Medicine
This study investigated trends in the study of phytochemical treatment of post-traumatic stress disorder (PTSD).
The Web of Science database (2007–2022) was searched using the search terms “phytochemicals” and “PTSD,” and relevant literature was compiled. Network clustering co-occurrence analysis and qualitative narrative review were conducted.
Three hundred and one articles were included in the analysis of published research, which has surged since 2015 with nearly half of all relevant articles coming from North America. The category is dominated by neuroscience and neurology, with two journals, Addictive Behaviors and Drug and Alcohol Dependence, publishing the greatest number of papers on these topics. Most studies focused on psychedelic intervention for PTSD. Three timelines show an “ebb and flow” phenomenon between “substance use/marijuana abuse” and “psychedelic medicine/medicinal cannabis.” Other phytochemicals account for a small proportion of the research and focus on topics like neurosteroid turnover, serotonin levels, and brain-derived neurotrophic factor expression.
Research on phytochemicals and PTSD is unevenly distributed across countries/regions, disciplines, and journals. Since 2015, the research paradigm shifted to constitute the mainstream of psychedelic research thus far, leading to the exploration of botanical active ingredients and molecular mechanisms. Other studies focus on anti-oxidative stress and anti-inflammation.
Please cite this article as: Gao B, Qu YC, Cai MY, Zhang YY, Lu HT, Li HX, Tang YX, Shen H. Phytochemical interventions for post-traumatic stress disorder: A cluster co-occurrence network analysis using CiteSpace. J Integr Med. 2023; 21(4):385–396.
Characterizing heterogeneity among people who use cannabis for medicinal reasons: A latent class analysis of a nationally representative Canadian sample
2023, International Journal of Drug Policy
Many individuals who use cannabis report doing so for medicinal reasons. Few studies have explored heterogeneity within this population, which may be important to inform targeted interventions. This study used latent class analysis to identify subgroups of people who use cannabis for medicinal reasons and their sociodemographic and cannabis-risk-related correlates.
Data were drawn from the 2019 Canadian Alcohol and Drugs Survey, which is a representative survey of Canadians ages 15 years and older. Data from 814 individuals reporting past-year use of cannabis for medicinal or mixed medicinal and non-medicinal reasons were included. Latent class analysis was conducted with forms of cannabis used, cannabis use frequency, concurrent non-medicinal cannabis use, and the medical conditions and symptoms cannabis was used to manage as indicators.
Four distinct latent classes of medicinal cannabis use were identified: a non-daily cannabis flower for mental health and sleep class (39.56% of the sample), a non-daily cannabis flower for pain class (26.41% of the sample), a non-daily cannabis oil for physical health class (20.15% of the sample), and a daily multi-form cannabis for mental health and non-medical reasons class (13.88% of the sample). Sociodemographic factors and risk level for cannabis-related harms were associated with latent class membership.
Results of this study reveal considerable heterogeneity among people reporting medicinal cannabis use and suggest that the distinct patterns of cannabis use behaviors and motives observed may be important for understanding risk for cannabis-related harms in this population. Findings underscore a need for harm reduction interventions tailored toward specific patterns of medicinal cannabis use.
Self-reported Medicinal Cannabis Use as an Alternative to Prescription and Over-the-counter Medication Use Among US Military Veterans
2023, Clinical Therapeutics
Mental and other physical health concerns and substance use disorder are common and co-occurring events experienced by US veterans. Treatment with medicinal cannabis is a potential alternative to unwanted medication use for veterans, but more clinical and epidemiologic research is needed to understand the risks and benefits.
Data were collected from a cross-sectional, self-reported, anonymous survey asking US veterans about their health conditions, medical treatments, demographics, and medicinal cannabis use along with its self-reported effectiveness. In addition to descriptive statistics, logistic regression models were run to examine correlates of the use of cannabis as a substitution for prescription or over-the-counter medications.
A total of 510 veterans of US military service participated in the survey, which was administered between March 3 and December 31, 2019. The participants reported experiencing a variety of mental and other physical health conditions. Primary health conditions reported included chronic pain (196; 38%), PTSD (131; 26%), anxiety (47; 9%), and depression (26; 5%). Most participants (343; 67%) reported using cannabis daily. Many reported using cannabis to reduce the use of over-the-counter medications (151; 30%) including antidepressants (130; 25%), anti-inflammatories (89; 17%), and other prescription medications. Additionally, 463 veterans (91% of respondents) reported that medical cannabis helped them to experience a greater quality of life and 105 (21%) reported using fewer opioids as a result of their medical cannabis use. Veterans who were Black, who were female, who served in active combat, and who were living with chronic pain were more likely to report a desire to reduce the number of prescription medications they were taking (odds ratios = 2.92, 2.29, 1.79, and 2.30, respectively). Women and individuals who used cannabis daily were more likely to report active use of cannabis to reduce prescription medication use (odds ratios = 3.05 and 2.26).
Medicinal cannabis use was reported to improve quality of life and reduce unwanted medication use by many of the study participants. The present findings indicate that medicinal cannabis can potentially play a harm-reduction role, helping veterans to use fewer pharmaceutical medications and other substances. Clinicians should be mindful of the potential associations between race, sex, and combat experience and the intentions for and frequency of medicinal cannabis use.
A call for qualitative and mixed-methods research on gambling and cannabis
2023, Addictive Behaviors Reports
Gambling disorder and cannabis use disorder are both considered major public health issues. Despite the well-documented frequency of substance use disorders among people with gambling disorder, little is known about the experiences of those who both engage with gambling and cannabis. A scoping review was undertaken to investigate studies focusing on the experiences of people who gamble and use cannabis. Unexpectedly, no qualitative or mixed-methods studies that included an in-depth qualitative component to study the lived experiences of this population were found. This absence highlights the critical need to diversify research methods and fill the gap in knowledge of the lived experiences of people who both gamble and consume cannabis.

View all citing articles on Scopus

View full text

ReviewMedical cannabis and mental health: A guided systematic review

Highlights

Abstract

Section snippets

Background

Methodology

Results

Summary

Conflict of interest

Contributors

Acknowledgement

Psychiatry Research

Addictive Behaviors

Journal of Affective Disorders

The International Journal on Drug Policy

Addictive Behaviors

Addictive Behaviors

Drug and Alcohol Dependence

Journal of Adolescent Health

Psychiatry Research

Addictive Behaviors

Journal of Anxiety Disorders

Behaviour Research and Therapy

Addictive Behaviors

Journal of Psychiatric Research

Drug and Alcohol Dependence

Addictive Behaviors

Journal of Affective Disorders

Journal of Affective Disorders

Addictive Behaviors

Drug and Alcohol Dependence

Addictive Behaviors

Biological Psychiatry

Journal of Affective Disorders

Neuropsychopharmacology

Journal of the American Academy of Child and Adolescent Psychiatry

Drug and Alcohol Dependence

Addictive Behaviors

Drug and Alcohol Dependence

Schizophrenia Research

The relationship between cannabis and violence: A review

Psychological Bulletin

Prospectively surveying health-related quality of life and symptom relief in a lot-based sample of medical cannabis-using patients in urban Washington state reveals managed chronic illness and debility

American Journal of Hospice & Palliative Medicine

Differences in the marijuana expectancies of adolescents in relation to marijuana use

Substance Use & Misuse

Diagnostic and statistical manual of mental disorders

Diagnostic and statistical manual of mental disorders

Medical marijuana laws, traffic fatalities, and alcohol consumption

Journal of Law and Economics

Medical marijuana laws and suicides by gender and age

American Journal of Public Health

Testing the self-medication hypothesis of depression and aggression in cannabis-dependent subjects

Psychological Medicine

Mental disorders and violence in a total birth cohort: Results from the Dunedin study

Archives of General Psychiatry

Cannabinoids in bipolar affective disorder: A review and discussion of their therapeutic potential

Journal of Psychopharmacology

Sleep disturbances: Implications for cannabis use, cannabis use cessation, and cannabis use treatment

Current Addiction Reports

Sleep quality moderates the relation between depression symptoms and problematic cannabis use among medical cannabis users

The American Journal of Drug and Alcohol Abuse

Medical cannabis laws and opioid analgesic overdose mortality in the United States, 1999–2010

JAMA Internal Medicine

Secret “sober” pot smokers

Cannabis abuse and serious suicide attempts

Addiction

Efficacy and tolerability of high-dose dronabinol maintenance in HIV-positive marijuana smokers: A controlled laboratory study

Psychopharmacology

Narrative review of the safety and efficacy of marijuana for the treatment of commonly state-approved medical and psychiatric disorders

Addiction Science and Practice

Cannabidiol reduces the anxiety induced by simulated public speaking in treatment-naive social phobia patients

Neuropsychopharmacology

The link between dopamine function and apathy in cannabis users: An [18F]-DOPA PET imaging study

Psychopharmacology

Posttraumatic stress disorder and cannabis use characteristics among military veterans with cannabis dependence

The American Journal on Addictions

Prevalence of cannabis use disorder diagnoses among veterans in 2002, 2008, and 2009

Psychological Services

Review
Medical cannabis and mental health: A guided systematic review

The link between dopamine function and apathy in cannabis users: An [¹⁸F]-DOPA PET imaging study