Joint Effects: A Pilot Investigation of the Impact of Bipolar Disorder and Marijuana Use on Cognitive Function and Mood

A Systematic Review of the Molecular and Cellular Alterations Induced by Cannabis That May Serve as Risk Factors for Bipolar Disorder

BACKGROUND

Cannabis use is a risk factor of psychiatric illness, such as bipolar disorder type-I (BDI). Indeed, cannabis use strongly influences the onset and clinical course of BDI, although the biological mechanisms underlying this interaction remain unknown. Therefore, we have reviewed the biological mechanisms affected by cannabis use that may trigger BD.

METHODS

A systematic review was carried out of articles in which gene expression was studied in cannabis users or human-derived cells exposed to tetrahydrocannabinol (THC) or cannabidiol (CBD). A second systematic review was then performed to identify articles in which gene expression was studied in BDI samples, highlighting those that described alterations to the same molecular and cellular mechanisms affected by cannabis/THC/CBD.

RESULTS

The initial search identified 82 studies on cannabis and 962 on BDI. After removing duplicates and applying the inclusion/exclusion criteria, 9 studies into cannabis and 228 on BDI were retained. The molecular and cellular mechanisms altered by cannabis use or THC/CBD exposure were then identified, including neural development and function, cytoskeletal function, cell adhesion, mitochondrial biology, inflammatory related pathways, lipid metabolism, the endocannabinoid system, the hypocretin/orexin system, and apoptosis. Alterations to those activities were also described in 19 of 228 focused on BDI.

CONCLUSIONS

The biological mechanisms described in this study may be good candidates to the search for diagnostic biomarkers and therapeutic targets for BDI. Because cannabis use can trigger the onset of BD, further studies would be of interest to determine whether they are involved in the early development of the disorder, prompting early treatment.

Association of cannabis use with neurocognition in adolescents with bipolar disorder

BACKGROUND

Bipolar disorder (BD) and cannabis use are each associated with neurocognitive deficits in adolescents. However, little is known regarding the association of neurocognition with cannabis use among adolescents with BD. Therefore, we examined this topic in a sample of adolescents with BD and healthy control (HC) adolescents.

METHODS

Participants included 121 adolescents (n = 32 with BD and lifetime cannabis use (BDCB+), n = 31 with BD and no lifetime cannabis use (BDCB-), n = 58 HC with no lifetime cannabis use), aged 14-20 years. Five neurocognitive subtests of the computerized CANTAB battery were assessed. Groups were compared using an analysis of covariance (ANCOVA) covarying for age, sex, and intelligence quotient.

RESULTS

The three groups differed significantly on tests of visuospatial working memory (F = 4.41, p = 0.014, η p 2 = 0 . 07 ) and sustained attention (F = 5.15, p = 0.007, η p 2 = 0 . 08 ). Post hoc analyses revealed working memory scores were significantly worse in BDCB+ versus HC (p = 0.04, d = 0.59), and sustained attention was significantly worse in BDCB- versus HC (p = 0.006, d = 0.70).

CONCLUSION

These preliminary findings suggest that cannabis use among adolescents with BD is associated with working memory deficits. Future studies in larger samples are warranted to evaluate causation versus predisposition to cannabis use, and to evaluate duration, quantity, and potency of cannabis on neurocognition among adolescents with BD.

Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: A Systematic Review and Recommendations of Cannabis use in Bipolar Disorder and Major Depressive Disorder

BACKGROUND

Given the increasing acceptability and legalization of cannabis in some jurisdictions, clinicians need to improve their understanding of the effect of cannabis use on mood disorders.

OBJECTIVE

The purpose of this task force report is to examine the association between cannabis use and incidence, presentation, course and treatment of bipolar disorder and major depressive disorder, and the treatment of comorbid cannabis use disorder.

METHODS

We conducted a systematic literature review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searching PubMed, Embase, PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials from inception to October 2020 focusing on cannabis use and bipolar disorder or major depressive disorder, and treatment of comorbid cannabis use disorder. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to evaluate the quality of evidence and clinical considerations were integrated to generate Canadian Network for Mood and Anxiety Treatments recommendations.

RESULTS

Of 12,691 publications, 56 met the criteria: 23 on bipolar disorder, 21 on major depressive disorder, 11 on both diagnoses and 1 on treatment of comorbid cannabis use disorder and major depressive disorder. Of 2,479,640 participants, 12,502 were comparison participants, 73,891 had bipolar disorder and 408,223 major depressive disorder without cannabis use. Of those with cannabis use, 2,761 had bipolar disorder and 5,044 major depressive disorder. The lifetime prevalence of cannabis use was 52%-71% and 6%-50% in bipolar disorder and major depressive disorder, respectively. Cannabis use was associated with worsening course and symptoms of both mood disorders, with more consistent associations in bipolar disorder than major depressive disorder: increased severity of depressive, manic and psychotic symptoms in bipolar disorder and depressive symptoms in major depressive disorder. Cannabis use was associated with increased suicidality and decreased functioning in both bipolar disorder and major depressive disorder. Treatment of comorbid cannabis use disorder and major depressive disorder did not show significant results.

CONCLUSION

The data indicate that cannabis use is associated with worsened course and functioning of bipolar disorder and major depressive disorder. Future studies should include more accurate determinations of type, amount and frequency of cannabis use and select comparison groups which allow to control for underlying common factors.

Exploring associations between affect and marijuana use in everyday life via specification curve analysis

Although frequently hypothesized, the evidence for associations between affect and marijuana use in everyday life remains ambiguous. Inconsistent findings across existing work may be due, in part, to differences in study design and analytic decisions, such as study inclusion criteria, the operationalization of affect, or the timing of affect assessment. We used specification curves to assess the robustness of the evidence for affect predicting same-day marijuana use and marijuana use predicting next-day affect across several hundred models that varied in terms of decisions that reflect those typical in this literature (e.g., whether to average affect prior to marijuana use or select the affect report closest in time to marijuana use). We fitted these curves to data from two ecological momentary assessment studies of regular marijuana and/or alcohol using college students (N = 287). Results provided robust evidence that marijuana use was slightly less likely following experiences of negative affect and slightly more likely following positive affect. Specification curves suggested that differences in previous findings are most likely a function of the specific emotion items used to represent affect rather than differences in inclusion criteria, the temporal assessment and modeling of affect, or the covariates added to the model. There was little evidence for an association between marijuana use and next-day affect. Overall, our findings provide evidence against the predictions made by affect reinforcement models in college students and suggest that future research should model the associations of marijuana use with discrete emotional states rather than general negative and positive affect. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Endocannabinoid System and Exogenous Cannabinoids in Depression and Anxiety: A Review

Background: There is a growing liberalization of cannabis-based preparations for medical and recreational use. In multiple instances, anxiety and depression are cited as either a primary or a secondary reason for the use of cannabinoids. Aim: The purpose of this review is to explore the association between depression or anxiety and the dysregulation of the endogenous endocannabinoid system (ECS), as well as the use of phytocannabinoids and synthetic cannabinoids in the remediation of depression/anxiety symptoms. After a brief description of the constituents of cannabis, cannabinoid receptors and the endocannabinoid system, the most important evidence is presented for the involvement of cannabinoids in depression and anxiety both in human and from animal models of depression and anxiety. Finally, evidence is presented for the clinical use of cannabinoids to treat depression and anxiety. Conclusions: Although the common belief that cannabinoids, including cannabis, its main studied components-tetrahydrocannabinol (THC) and cannabidiol (CBD)-or other synthetic derivatives have been suggested to have a therapeutic role for certain mental health conditions, all recent systematic reviews that we report have concluded that the evidence that cannabinoids improve depressive and anxiety disorders is weak, of very-low-quality, and offers no guidance on the use of cannabinoids for mental health conditions within a regulatory framework. There is an urgent need for high-quality studies examining the effects of cannabinoids on mental disorders in general and depression/anxiety in particular, as well as the consequences of long-term use of these preparations due to possible risks such as addiction and even reversal of improvement.

Comorbidity and Coaggregation of Major Depressive Disorder and Bipolar Disorder and Cannabis Use Disorder in a Controlled Family Study

IMPORTANCE

Cannabis use disorder (CUD) is increasing in the US. Clarification of the potential mechanisms underlying the comorbidity between mood disorders and CUD may help prevent CUD.

OBJECTIVE

To examine co-occurrence and familial aggregation of CUD and mood disorder subtypes.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional, community-based study in the Washington, DC, metropolitan area, semistructured diagnostic interviews and family history reports assessed lifetime DSM-IV disorders in probands and relatives. Familial aggregation and coaggregation of CUD with mood disorders were estimated via mixed-effects models, adjusting for age, sex, recruitment source, and comorbid mood, anxiety, and other substance use disorders. A total of 586 adult probands (186 with bipolar disorder; 55 with CUD) and 698 first-degree relatives (91 with bipolar disorder; 68 with CUD) were recruited from a community screening of the greater Washington, DC, metropolitan area from May 2004 to August 2020. Inclusion criteria were ability to speak English, and availability and consent to contact at least 2 living first-degree relatives.

MAIN OUTCOMES AND MEASURES

Lifetime CUD in first-degree relatives.

RESULTS

Of 586 probands, 395 (67.4%) were female; among 698 relatives, 437 (62.6%) were female. The mean (SD) age was 47.5 (15.2) years for probands and 49.6 (18.0) years for relatives. In the proband group, 82 participants (14.0%) self-identified as African American or Black, 467 (79.7%) as White, and 37 (6.3%) as American Indian or Alaska Native, Asian, more than one race, or another race or ethnicity or declined to respond. In the relative group, 53 participants (7.6%) self-identified as African American or Black, 594 (85.1%) as White, and 51 (7.3%) as American Indian or Alaska Native, Asian, more than one race, or another race or ethnicity or declined to respond. These groups were combined to protect privacy owing to small numbers. CUD in probands (55 [9.4%]) was associated with an increase in CUD in relatives (adjusted odds ratio [aOR], 2.64; 95% CI, 1.20-5.79; P = .02). Bipolar disorder II (BP-II) in probands (72 [12.3%]) was also associated with increased risk of CUD in relatives (aOR, 2.57; 95% CI, 1.06-6.23; P = .04). However, bipolar disorder I (114 [19.5%]) and major depressive disorder (192 [32.8%]) in probands were not significantly associated with CUD in relatives. Among relatives, CUD was associated with BP-II (aOR, 4.50; 95% CI, 1.72-11.77; P = .002), major depressive disorder (aOR, 3.64; 95% CI, 1.78-7.45; P < .001), and mean (SD) age (42.7 [12.8] years with CUD vs 50.3 [18.3] years without CUD; aOR, 0.98; 95% CI, 0.96-1.00; P = .02). Familial coaggregation of BP-II with CUD was attenuated by the inclusion of comorbid anxiety disorders. Further, rates of CUD were highest in relatives with both a familial and individual history of BP-II (no familial or individual history of BP-II: 41 [7.2%]; familial history but no individual history of BP-II: 13 [19.1%]; individual history but no familial history of BP-II: 10 [22.2%]; familial and individual history of BP-II: 4 [28.6%]; Fisher exact test, P < .001). The onset of mood disorder subtypes preceded CUD in probands and relatives in most cases.

CONCLUSIONS AND RELEVANCE

The findings confirmed a familial aggregation of CUD. The increase in risk of CUD among relatives of probands with BP-II suggests that CUD may share a common underlying diathesis with BP-II. Taken together with the temporal precedence of depression and mania with respect to CUD onset, these findings highlight a potential role for BP-II intervention as CUD prevention.

Exploring the digital footprint of depression: a PRISMA systematic literature review of the empirical evidence

BACKGROUND

This PRISMA systematic literature review examined the use of digital data collection methods (including ecological momentary assessment [EMA], experience sampling method [ESM], digital biomarkers, passive sensing, mobile sensing, ambulatory assessment, and time-series analysis), emphasizing on digital phenotyping (DP) to study depression. DP is defined as the use of digital data to profile health information objectively.

AIMS

Four distinct yet interrelated goals underpin this study: (a) to identify empirical research examining the use of DP to study depression; (b) to describe the different methods and technology employed; (c) to integrate the evidence regarding the efficacy of digital data in the examination, diagnosis, and monitoring of depression and (d) to clarify DP definitions and digital mental health records terminology.

RESULTS

Overall, 118 studies were assessed as eligible. Considering the terms employed, "EMA", "ESM", and "DP" were the most predominant. A variety of DP data sources were reported, including voice, language, keyboard typing kinematics, mobile phone calls and texts, geocoded activity, actigraphy sensor-related recordings (i.e., steps, sleep, circadian rhythm), and self-reported apps' information. Reviewed studies employed subjectively and objectively recorded digital data in combination with interviews and psychometric scales.

CONCLUSIONS

Findings suggest links between a person's digital records and depression. Future research recommendations include (a) deriving consensus regarding the DP definition and (b) expanding the literature to consider a person's broader contextual and developmental circumstances in relation to their digital data/records.

The impact of substance use disorder comorbidity on cognition of individuals with bipolar disorder: A systematic review

The aim of this study is to describe whether Bipolar Disorder (BD) with Substance Use Disorder (SUD) comorbidity is associated with an increased cognitive impairment as compared to BD without SUD comorbidity. This is a systematic review. The literature search was conducted in three databases: PubMed, PsycINFO and Embase. A total of 2032 studies were screened after removing duplicates. 29 articles were included for full text screening, and a total of 14 articles were included in the systematic review. Multiple cognitive domains were assessed, including verbal, spatial and visual memory, and psychomotor and executive functioning. Over half the articles (64.3%, n=9) identified cognitive impairments in individuals with BD+SUD comorbidity as compared to individuals with BD without SUD comorbidity. In addition, individuals with the comorbidity exhibited more severe impairments on tests of executive functioning, and greater impairments in verbal and visual memory. The studies included in this systematic review reinforce that individual with comorbidity of BD and SUD have increased cognitive impairment as compared to individuals with BD without SUD comorbidity. Executive functioning was the most impaired cognitive domain found across the studies included in this review. Intervention strategies focused on executive functioning would be beneficial for this specific population.

Associations between cannabis use, cannabis use disorder, and mood disorders: longitudinal, genetic, and neurocognitive evidence

RATIONALE

Cannabis use among people with mood disorders increased in recent years. While comorbidity between cannabis use, cannabis use disorder (CUD), and mood disorders is high, the underlying mechanisms remain unclear.

OBJECTIVES

We aimed to evaluate (1) the epidemiological evidence for an association between cannabis use, CUD, and mood disorders; (2) prospective longitudinal, genetic, and neurocognitive evidence of underlying mechanisms; and (3) prognosis and treatment options for individuals with CUD and mood disorders.

METHODS

Narrative review of existing literature is identified through PubMed searches, reviews, and meta-analyses. Evidence was reviewed separately for depression, bipolar disorder, and suicide.

RESULTS

Current evidence is limited and mixed but suggestive of a bidirectional relationship between cannabis use, CUD, and the onset of depression. The evidence more consistently points to cannabis use preceding onset of bipolar disorder. Shared neurocognitive mechanisms and underlying genetic and environmental risk factors appear to explain part of the association. However, cannabis use itself may also influence the development of mood disorders, while others may initiate cannabis use to self-medicate symptoms. Comorbid cannabis use and CUD are associated with worse prognosis for depression and bipolar disorder including increased suicidal behaviors. Evidence for targeted treatments is limited.

CONCLUSIONS

The current evidence base is limited by the lack of well-controlled prospective longitudinal studies and clinical studies including comorbid individuals. Future studies in humans examining the causal pathways and potential mechanisms of the association between cannabis use, CUD, and mood disorder comorbidity are crucial for optimizing harm reduction and treatment strategies.

Multimodal Correlates of Cannabis Use among U.S. Veterans with Bipolar Disorder: An Integrated Study of Clinical, Cognitive, and Functional Outcomes

Objective: Cannabis use (CU) is common among persons with bipolar disorder (BD). Evidence suggests that CU is associated with poorer outcomes among persons with BD; however, these findings remain inconsistent. The present exploratory study aims to examine clinical, functional, and cognitive correlates of CU among persons with BD. Methods: U.S. veterans with BD type I who participated in a large-scale, nationwide study were categorized into four groups: current CU, past CU, past other drug use, and no drug use. Bivariate analyses, univariate analyses of covariance, and Levene's Test for Equality of Variance were used to compare groups on clinical, cognitive, and functional measures. Results: Of 254 (84.6% male) veterans with BD type I included in the analyses, 13 (5.1%) had current CU, 37 (14.5%) past CU, 77 (30.3%) past other drug use, and 127 (50%) reported no drug use. BD with CU was associated with post-traumatic stress disorder (PTSD) and experiencing lifetime suicidal ideation. Notably, current CU was associated with higher working memory performance, compared to both past CU and no drug use. Likewise, current CU was associated with higher functional capacity, compared to past CU as well as no drug use. Conclusions: These findings contribute to the growing literature on the complex effects of cannabis on BD. As the commercialization and legalization of cannabis increases, further research in this area is warranted to quantify posed risks to this population, and thereby guide clinical decision-making.

The relationship between cannabis use and cognition in people with bipolar disorder: A systematic scoping review

Bipolar disorder (BD) and cannabis use are highly comorbid and are each associated with cognitive impairment.  Given the prevalence of cannabis use in people with BD, it is important to understand whether the two interact to impact cognitive function. We performed a systematic scoping review to determine what is currently known in this field. We systematically searched PubMed, Embase, CINAHL, Web of Science, and PsycINFO for studies on the relationship between cannabis use and cognition in people with BD or relevant animal models. Six observational human studies and no animal studies met inclusion criteria. Two studies found cannabis use in BD was associated with better performance in some cognitive domains, while three studies found no association. One study found cannabis use in BD was associated with worse overall cognition. Overall, most identified studies suggest cannabis use is not associated with significant cognitive impairment in BD; however, the scope of knowledge in this field is limited, and more systematic studies are clearly required. Future studies should focus on longitudinal and experimental trials, and well-controlled observational studies with rigorous quantification of the onset, frequency, quantity, duration, and type of cannabis use, as well as BD illness features.

Cognitive Impairment Among Tunisian Bipolar Patients: a Case-Control Study

Studies exploring the cognitive performance of bipolar patients have mainly been conducted in Western countries. To our knowledge, no surveys have been reported to date in Tunisia. The present work aimed to evaluate the cognitive functions, in the three domains of memory, attention and executive functions, among a sample of Tunisian individuals with bipolar disorder, during the remission period, compared to healthy control subjects. We found that Cognitive functions in euthymic patients with bipolar disorder were significantly more impaired than in controls, apart from the working memory that did not show a significant difference between the two groups. Our findings confirm cognitive deficits associated with bipolar disorder, even at a distance from the symptomatic phases of the disease. Thus, these anomalies may be considered as a trait marker of the disease. A better understanding of cognitive decline certainly allows for better management of psychiatric pathologies, thus improving patients' social skills and quality of life.

Cannabinoids and their therapeutic applications in mental disorders

Mental disorders represent a significant public health burden worldwide due to their high prevalence, chronically disabling nature, and substantial impact on quality of life. Despite growing knowledge of the pathological mechanisms that underlie the development of these disorders, a high percentage of patients do not respond to first-line clinical treatments; thus, there is a strong need for alternative therapeutic approaches. During the past half-century, after the identification of the endocannabinoid system and its role in multiple physiological processes, both natural and synthetic cannabinoids have attracted considerable interest as putative medications in pathological conditions such as, but not exclusive to, mental disorders. Here, we provide a summary of cannabinoid effects in support of possible therapeutic applications for major depression, bipolar disorder, anxiety, posttraumatic stress disorder, and schizophrenia. Considering this evidence, highlighted benefits and risks of cannabinoid use in the management of these illnesses require further experimental study.
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Cognitive impairment in individuals with bipolar disorder with and without comorbid alcohol and/or cocaine use disorders

BACKGROUND

Bipolar disorder (BD) frequently co-occurs with substance use disorders (SUDs), and both are associated with cognitive impairment. This study compares cognition between individuals with BD with and without current alcohol use disorder (AUD), cocaine use disorder (CUD), or both, as these disorders may be linked with additive cognitive impairment.

METHODS

Baseline data were analyzed from five clinical studies of individuals with the aforementioned disorders (N = 373). Participants were grouped as follows: BD-only, BD + AUD, BD + CUD, or BD + AUD + CUD. Cognition was assessed with the Rey Auditory Verbal Learning Test (RAVLT) (verbal learning and memory) and Stroop Color Word Test (executive function). Multiple linear regression models determined if SUD diagnosis, among other demographic and clinical variables, predicted each cognitive test's T-score. Regression equations were used to compute each group's mean T-scores.

RESULTS

All groups demonstrated below-average mean T-scores on all tests, with no significant between-group score differences. RAVLT total T-scores were lower than Stroop color-word T-scores within all groups (non-overlapping 95% confidence intervals). Higher daily cocaine use predicted higher Stroop T-scores (p < 0.01) and RAVLT delayed recall T-scores (p < 0.05). No other non-demographic variable, including AUD/CUD group status, predicted cognitive performance.

LIMITATIONS

A full cognitive battery and some relevant variables (e.g. BD lifetime illness course) were not available. Many participants (42.1%) had additional SUDs.

CONCLUSIONS

BD with and without AUD/CUD was found to be associated with greater deficits in verbal learning and memory than in executive function. Addressing these impaired domains in dually-diagnosed patients may improve treatment and functional outcomes.

Compliance and Retention With the Experience Sampling Method Over the Continuum of Severe Mental Disorders: Meta-Analysis and Recommendations

Background

Despite the growing interest in the experience sampling method (ESM) as a data collection tool for mental health research, the absence of methodological guidelines related to its use has resulted in a large heterogeneity of designs. Concomitantly, the potential effects of the design on the response behavior of the participants remain largely unknown.

Objective

The objective of this meta-analysis was to investigate the associations between various sample and design characteristics and the compliance and retention rates of studies using ESM in mental health research.

Methods

ESM studies investigating major depressive disorder, bipolar disorder, and psychotic disorder were considered for inclusion. Besides the compliance and retention rates, a number of sample and design characteristics of the selected studies were collected to assess their potential relationships with the compliance and retention rates. Multilevel random/mixed effects models were used for the analyses.

Results

Compliance and retention rates were lower for studies with a higher proportion of male participants (P<.001) and individuals with a psychotic disorder (P<.001). Compliance was positively associated with the use of a fixed sampling scheme (P=.02), higher incentives (P=.03), higher time intervals between successive evaluations (P=.02), and fewer evaluations per day (P=.008), while no significant associations were observed with regard to the mean age of the sample, the study duration, or other design characteristics.

Conclusions

The findings demonstrate that ESM studies can be carried out in mental health research, but the quality of the data collection depends upon a number of factors related to the design of ESM studies and the samples under study that need to be considered when designing such protocols.

Cannabis and mental illness: a review

With the increasing push to legalize cannabis in Western nations, there is a need to gage the potential impact of this policy change on vulnerable populations, such as those with mental illness, including schizophrenia, mood, and anxiety disorders. This is particularly important as there are strong motives in these individuals to seek short-term reward (e.g., "getting high"). Nonetheless, data to support the beneficial effects of cannabis use in psychiatric populations are limited, and potential harms in patients with psychotic and mood disorders have been increasingly documented. This article reviews the effects of cannabis in people with mental illness. Then, we provide a reconciliation of the addiction vulnerability and allostatic hypotheses to explain co-morbidity addiction in mentally ill cannabis users, as well as to further aid in developing a rational framework for the assessment and treatment of problematic cannabis use in these patients.

Medical cannabis patterns of use and substitution for opioids & other pharmaceutical drugs, alcohol, tobacco, and illicit substances; results from a cross-sectional survey of authorized patients

BACKGROUND

A 239-question cross-sectional survey was sent out via email in January 2017 to gather comprehensive information on cannabis use from Canadian medical cannabis patients registered with a federally authorized licensed cannabis producer, resulting in 2032 complete surveys.

METHODS

The survey gathered detailed demographic data and comprehensive information on patient patterns of medical cannabis use, including questions assessing the self-reported impact of cannabis on the use of prescription drugs, illicit substances, alcohol, and tobacco.

RESULTS

Participants were 62.6% male (n = 1271) and 91% Caucasian (n = 1839). The mean age was 40 years old, and pain and mental health conditions accounted for 83.7% of all respondents (n = 1700). Then, 74.6% of respondents reported daily cannabis use (n = 1515) and mean amount used per day was 1.5 g. The most commonly cited substitution was for prescription drugs (69.1%, n = 953), followed by alcohol (44.5%, n = 515), tobacco (31.1%, n = 406), and illicit substances (26.6%, n = 136). Opioid medications accounted for 35.3% of all prescription drug substitution (n = 610), followed by antidepressants (21.5%, n = 371). Of the 610 mentions of specific opioid medications, patients report total cessation of use of 59.3% (n = 362).

CONCLUSIONS

This study offers a unique perspective by focusing on the use of a standardized, government-regulated source of medical cannabis by patients registered in Canada's federal medical cannabis program. The findings provide a granular view of patient patterns of medical cannabis use, and the subsequent self-reported impacts on the use of opioids, alcohol, and other substances, adding to a growing body of academic research suggesting that increased regulated access to medical and recreational cannabis can result in a reduction in the use of and subsequent harms associated with opioids, alcohol, tobacco, and other substances.

The level of evidence of medical marijuana use for treating disabilities: a scoping review

Purpose: Twenty-nine states have bypassed federal regulations by legalizing marijuana (MJ) either medicinally, recreationally or both. The FDA states that there is no empirical evidence that MJ is effective to treat these disorders. With over a billion individuals living with a disability across the globe, it is crucial to fully research the efficaciousness and safety of medical MJ to treat this population. The purpose to present the results of a scoping review of studies focused on the levels of evidence currently available on medical MJ's efficacy in treatment across a large range of disabilities.Methods: Databases were searched for research articles on the current level of evidence to support medical MJ use among people with disabilities.Results: Forty-one peer reviewed articles met the inclusion criteria. Articles focused on attention deficit hyperactivity disorder, post-traumatic stress disorder, depression, schizophrenia, spinal cord injury, multiple sclerosis/movement disorders, fibromyalgia, epilepsy, with some that focused on multiple disabilities.Conclusions: The level of evidence for the use of medical MJ among people with disabilities varies greatly, and has a clear lack of methodologically sound studies. Overall, medical MJ does not improve the level of functioning, but it may improve the overall quality of life for people with disabilities.Implications for RehabilitationEpilepsy can be a disabling chronic disorder which not only impacts physically but can restricts quality of life.Quality of life is diminished even more with treatment resistant epilepsy.Chronic pain is the leading cause of disability and is the most common cause of long-term disability.There is sufficient evidence that medical marijuana is effective in treating epileptic seizures and chronic pain.Medical marijuana may improve the level of functioning and quality of life for individuals with certain disabilities.

Affect and cannabis use in daily life: a review and recommendations for future research

BACKGROUND

Although cannabis is often used for the purposes of relieving negative affective states such as anxiety and depression, the associations between cannabis use and affect in daily life are unclear. Ecological momentary assessment (EMA) has been used to study these associations in individuals' natural environments, providing more ecological validity, minimizing retrospective bias, and allowing for the analysis of within-individual processes over time. This review focuses on studies that utilized EMA to examine daily-life associations of cannabis use and negative and positive affective states.

METHODS

We review the findings of the 19 articles that met inclusion criteria, including clinical and community samples.

RESULTS

Results provide equivocal evidence regarding relations between cannabis use and affect for community samples. Findings are mixed for clinical samples as well, but more consistent patterns emerge for general negative affect (NA) and anger/hostility at the momentary level; cannabis use may be more likely following increased NA and lead to decreases in NA and anger/hostility in psychiatric populations.

CONCLUSIONS

Findings support a negative reinforcement hypothesis for clinical samples in terms of general NA and anger/hostility. However, discrepancies among studies point to a need to thoroughly characterize samples, consider motives for and expectancies of use, improve quantification of cannabis use, and consider co-use with other substances. Additional design recommendations are also offered for future studies.

Cannabis regulatory science: risk-benefit considerations for mental disorders

The evolving legal cannabis landscape in the US continues to present novel regulatory challenges that necessitate the development of a Cannabis Regulatory Science. Two specific issues of concern within Cannabis Regulatory Science are (1) the impact that cannabis use has on the incidence, prevalence, and severity of mental disorders, and (2) how cannabis laws and regulations modify this impact. This paper first provides several conceptual points that are useful for evaluating the relationship between cannabis use and mental disorders. Second, it selectively reviews and comments on data relevant to the relationship between cannabis use and depression, several forms of anxiety, post-traumatic stress disorder, schizophrenia, and bipolar disorder. Next, regulatory and public health parallels between the nascent cannabis industry and the pharmaceutical, tobacco, and alcohol industries are discussed. The focus is on specific types of industry practices that may harm those with or at risk for mental disorders. Recommendations are then offered for legal cannabis regulations that could mitigate this harm. Last, future research goals are discussed for building the field of Cannabis Regulatory Science and addressing the potential negative impact of cannabis on those with mental disorders.

The impact of current cannabis use on general cognitive function in people with psychotic illness

BACKGROUND

Despite growing research, it remains unclear if cannabis use is associated with additive cognitive impairment in people with psychotic illness and whether exposure in early adolescence is associated with poorer cognitive performance in adulthood.

METHODS

This cross-sectional study of a nationally representative sample of 1199 adults with psychotic illness compared current cognition (digit symbol coding) of 297 current users of cannabis (used in the past year), 460 past users (used previously but not in the past year) and 442 non-users (never used). Multiple logistic regression was used to examine whether cognitive performance of cannabis-user groups varied by exposure age and diagnosis (non-affective/affective psychoses).

RESULTS

Unadjusted analysis showed current cannabis users had significantly higher odds of impaired cognitive function compared to non-users (odds ratio=1.52, 95%CI=1.04-2.22). After adjusting for potential confounders, differences between the three groups were not significant. Exposure age was not significant in adjusted analysis. In participants with nonaffective psychoses, cognitive ability of current cannabis users did not differ from non-users. However, in participants with affective psychoses, using cannabis in the last year was a significant predictor of impaired cognitive function (odds ratio=2.25, 95%CI=1.05-4.84).

CONCLUSION

Among people with psychotic illness, there was no significant difference in cognitive function between current, past and non-users of cannabis. However, when we compared cognitive performance of the three cannabis groups by diagnostic grouping, current cannabis use had a significant negative relationship with cognitive function in people with affective psychoses, but not in those with non-affective psychoses. This finding requires replication and further investigation.

Splendor in the Grass? A Pilot Study Assessing the Impact of Medical Marijuana on Executive Function

Currently, 25 states and Washington DC have enacted full medical marijuana (MMJ) programs while 18 states allow limited access to MMJ products. Limited access states permit low (or zero) tetrahydrocannabinol (THC) and high cannabidiol (CBD) products to treat specified conditions such as uncontrolled epilepsy. Although MMJ products are derived from the same plant species as recreational MJ, they are often selected for their unique cannabinoid constituents and ratios, not typically sought by recreational users, which may impact neurocognitive outcomes. To date, few studies have investigated the potential impact of MMJ use on cognitive performance, despite a well-documented association between recreational marijuana (MJ) use and executive dysfunction. The current study assessed the impact of 3 months of MMJ treatment on executive function, exploring whether MMJ patients would experience improvement in cognitive functioning, perhaps related to primary symptom alleviation. As part of a larger longitudinal study, 24 patients certified for MMJ use completed baseline executive function assessments and 11 of these so far have returned for their first follow-up visit 3 months after initiating treatment. Results suggest that in general, MMJ patients experienced some improvement on measures of executive functioning, including the Stroop Color Word Test and Trail Making Test, mostly reflected as increased speed in completing tasks without a loss of accuracy. On self-report questionnaires, patients also indicated moderate improvements in clinical state, including reduced sleep disturbance, decreased symptoms of depression, attenuated impulsivity, and positive changes in some aspects of quality of life. Additionally, patients reported a notable decrease in their use of conventional pharmaceutical agents from baseline, with opiate use declining more than 42%. While intriguing, these findings are preliminary and warrant further investigation at additional time points and in larger sample sizes. Given the likelihood of increased MMJ use across the country, it is imperative to determine the potential impact of short- and long-term treatment on cognitive performance as well as the efficacy of MMJ treatment itself.