Comorbid mood, psychosis, and marijuana abuse disorders: a theoretical review

Comorbid Cannabis Use Disorder with Major Depression and Generalized Anxiety Disorder: A Systematic Review with Meta-analysis of Nationally Representative Epidemiological Surveys

BACKGROUND

Studies have shown a high degree of comorbidity between cannabis use disorder (CUD) and other mental illnesses. However, there is a paucity of research on the comorbidity between CUD with major depression (MD) and generalized anxiety disorder (GAD). This systematic review with meta-analysis aimed to assess the prevalence and strength of association between co-morbid CUD with MD and GAD.

METHODS

An extensive search of Medline, CINAHL, PsycINFO, EMBASE, and grey literature were conducted to cover articles published between January 1^st, 1980, and July 31^st, 2020. Inclusion criteria were publications in English Language, original research, nationally representative samples, and non-clinical randomly selected adult populations. A systematic review and meta-analysis for the prevalence and ORs for comorbid CUD with MD or GAD were done.

RESULTS

A total of 67 articles were identified by the electronic searches. A full-text review yielded 8 publications on nationally representative epidemiological surveys. 12-month and lifetime comorbidity estimates were extracted and used for the meta-analysis. CUD was strongly associated with MDE (OR 3.22; 2.31 - 4.49) and with GAD (OR 2.99; 2.14 - 4.16).

LIMITATIONS

Limitations of this study include the heterogeneity observed due to the combination of studies from different geographic regions with different modifications of diagnostic criteria and varied response rates. This was addressed with a random-effects model.

CONCLUSION

This review confirms the evidence of high prevalence and a 3-fold comorbid association between CUD with MD and CUD with GAD. Implementation of evidence-based policy interventions with effective, integrated management of comorbid CUDs with psychiatric disorders may contribute to positive patient outcomes.

Health-related quality of life in patients treated with atypical antipsychotics

Objective:

To assess health-related quality of life and associated factors in patients treated with atypical antipsychotics, as well as to determine utility values using the EuroQol-5D-3L instrument.

Methods:

A cross-sectional study was conducted at a state-run pharmacy in the Brazilian National Health System. Individuals were included if they were using a single atypical antipsychotic and completed the EuroQol-5D-3L. Sociodemographic, behavioral, and clinical data were collected. The dependent variable was the EuroQol-5D-3L utility score. Associations between the independent variables and the dependent variable were analyzed in a multiple linear regression model.

Results:

A total of 394 patients were included, and their mean utility score was 0.664±0.232. Patients treated with clozapine had the highest mean score (0.762 [0.202]), followed by olanzapine (0.687 [0.230]), risperidone (0.630 [0.252]), ziprasidone (0.622 [0.234]), and quetiapine (0.620 [0.243]). The following variables were related to higher utility scores: income, employment, clozapine use, no illicit psychoactive substance use, no suicide attempts, and no comorbidities.

Conclusion:

Evaluating health-related quality of life differences in the available atypical antipsychotics can facilitate the choice of treatment, improve health outcomes, and ensure rational prescriptions.

Modeling variables associated with personal recovery among service users with mental disorders using community-based services

BACKGROUND

Mental health research is evolving toward the identification of conceptual models and associated variables, which may provide a better understanding of personal recovery, given its importance for individuals affected by mental disorders (MDs).

AIMS

This article evaluated personal recovery in a sample of adults with MDs using an adapted conceptual framework based on the Andersen behavioral model, which evaluates predisposing, enabling and needs factors in service use.

METHODS

The study design was cross-sectional and included 327 mental health service users recruited across four local health service networks in Quebec (Canada). Data were collected using seven standardized instruments and participant medical records. Structural equation modeling was performed.

RESULTS

Quality of life (QOL), an enabling factor, was most strongly associated with personal recovery. Health behavior variables associated with recovery included the following: use of alcohol services, having a family physician, consulting a psychologist, use of food banks, consulting fewer professionals and not using drug services. Regarding needs factors, higher numbers of needs, lower severity of unmet health, social and basic needs and absence of mood disorders were also associated with personal recovery. No predisposing factors emerged as significant in the model.

CONCLUSION

Findings suggest that QOL, needs variables and comprehensive service delivery are important in personal recovery. Services should be individualized to the health, social and basic needs of service users, particularly those with mood disorders or co-occurring mental health/substance use disorders.

Cannabis consumption and psychosis or schizophrenia development

OBJECTIVE:

Cannabis consumption produces psychopathology, in some cases psychotic episodes, which are of our interest in this work. However, the relationship between cannabis use and psychosis has not been fully elucidated. The objectives of this work are to (1) review the current state of knowledge on the association of cannabis use with the risk of the development of psychosis or psychotic symptoms in people without schizophrenia and (2) assess the consistency of the hypothesis that cannabis use is associated with increased risk of psychosis in people without schizophrenia.

METHOD:

This work included research done in humans until May 2018 with the keywords 'cannabis' and 'psychosis', published in English and Spanish, in the PubMed database.

RESULTS:

In all, 66 papers were analyzed, of which 23 were cohort trials and 43 were reviews.

CONCLUSION:

Cannabis use doubles the risk of developing psychosis in vulnerable people. There even exists a relationship regarding the dose used and the age of first use. Gene-environment interactions that modulate the association between cannabis use and the presence of psychosis have also been described.

Δ9-tetrahydrocannabinol (Δ9-THC) administration after neonatal exposure to phencyclidine potentiates schizophrenia-related behavioral phenotypes in mice

The clinical onset of schizophrenia often coincides with cannabis use in adolescents and young adults. However, the neurobiological consequences of this co-morbidity are not well understood. In this study, we examined the effects of Δ9-THC exposure during early adulthood on schizophrenia-related behaviors using a developmental mouse model of schizophrenia. Phencyclidine (PCP) or saline was administered once in neonatal mice (at P7; 10mg/kg). In turn, Δ9-THC or saline was administered sub-acutely later in life to cohorts of animals who had received either PCP or saline (P55-80, 5mg/kg). Mice who were administered PCP alone displayed behavioral changes in the Morris water waze (MWM) and pre-pulse inhibition (PPI) task paradigm that were consistent with schizophrenia-related phenotypes, but not in the locomotor activity or novel object recognition (NOR) task paradigms. Mice who were administered PCP and then received Δ9-THC later in life displayed behavioral changes in the locomotor activity paradigm (p<0.001) that was consistent with a schizophrenia-related phenotype, as well as potentiated changes in the NOR (p<0.01) and MWM (p<0.05) paradigms as compared to mice that received PCP alone. Decreased cortical receptor expression of NMDA receptor 1 subunit (NR1) was observed in mice that received PCP and PCP+Δ9-THC, while mice that received Δ9-THC and PCP+Δ9-THC displayed decreases in CB1 receptor expression. These findings suggest that administration of Δ9-THC during the early adulthood can potentiate the development of schizophrenia-related behavioral phenotypes induced by neonatal exposure to PCP in mice.

Typology of individuals with substance dependence based on a Montreal longitudinal catchment area study

This study sought to develop a typology of individuals with substance dependence (ISD) based on a longitudinal survey (n = 2,434) and 121 ISD. The latter were divided into three groups: newly abstinent individuals, chronic dependents and acute dependents. Individuals' typology was developed by cluster analysis. Newly abstinent individuals had fewer emotional problems and mental disorders in the previous 12 months. Four classes of ISD were identified, labelled respectively "chronic multi-substance consumption and mental disorders comorbidities," "multi-substance consumption," "alcohol and marijuana consumption" and "alcohol consumption only." Strategies adapted to each of these profiles could be promoted for more effective treatment.

Pathways to psychosis in cannabis abuse

Cannabis has been implicated as a risk factor for the development of schizophrenia, but the exact biological mechanisms remain unclear. In this review, we attempt to understand the neurobiological pathways that link cannabis use to schizophrenia. This has been an area of great debate; despite similarities between cannabis users and schizophrenia patients, the evidence is not sufficient to establish cause-and-effect. There have been advances in the understanding of the mechanisms of cannabis dependence as well as the role of the cannabinoid system in the development of psychosis and schizophrenia. The neurobiological mechanisms associated with the development of psychosis and effects from cannabis use may be similar but remain elusive. In order to better understand these associations, this paper will show common neurobiological and neuroanatomical changes as well as common cognitive dysfunction in cannabis users and patients of schizophrenia. We conclude that epidemiologic evidence highlights potential causal links; however, neurobiological evidence for causality remains weak.

Profiles Associated Respectively with Substance Dependence Only, Mental Disorders Only and Co-occurring Disorders

This study sought to identify profiles associated with substance dependence only, mental disorders only and co-occurring disorder respectively, using a broad range of socio-demographic, socio-economic, health beliefs, clinical and health services utilization variables concurrently. Based on a broad analytic framework, 423 participants diagnosed with substance dependence only, mental disorders only or co-occurring disorders within a 12-months period were studied. The study used comparison analysis, and a multinomial logistic regression model. Participants with dependence only and mental disorders only were in contrast in terms of gender, age, marital status, self-perception of physical health, perception of the physical conditions of their neighbourhood, impulsiveness, psychological distress and visit with a family physician in previous 12-months, while those with co-occurring disorders were in an intermediary position between the other two groups. Public authorities should especially promote strategies that could increase the capacity of family physicians to take care of individuals with substance dependence only.

Stress, sex, and addiction: potential roles of corticotropin-releasing factor, oxytocin, and arginine-vasopressin

Stress sensitivity and sex are predictive factors for the development of neuropsychiatric disorders. Life stresses are not only risk factors for the development of addiction but also are triggers for relapse to drug use. Therefore, it is imperative to elucidate the molecular mechanisms underlying the interactions between stress and drug abuse, as an understanding of this may help in the development of novel and more effective therapeutic approaches to block the clinical manifestations of drug addiction. The development and clinical course of addiction-related disorders do appear to involve neuroadaptations within neurocircuitries that modulate stress responses and are influenced by several neuropeptides. These include corticotropin-releasing factor, the prototypic member of this class, as well as oxytocin and arginine-vasopressin that play important roles in affiliative behaviors. Interestingly, these peptides function to balance emotional behavior, with sexual dimorphism in the oxytocin/arginine-vasopressin systems, a fact that might play an important role in the differential responses of women and men to stressful stimuli and the specific sex-based prevalence of certain addictive disorders. Thus, this review aims to summarize (i) the contribution of sex differences to the function of dopamine systems, and (ii) the behavioral, neurochemical, and anatomical changes in brain stress systems.

Suicidal ideation among medical students of Pakistan: a cross-sectional study

Few studies have investigated suicidal ideation among medical students in the developing world. We found only one report on suicidal ideation among medical students in Pakistan published in the year 2005. The present cross-sectional survey on suicidal ideation conducted in July 2013 involved 331 medical students of Dow University of Health Sciences, Karachi, Pakistan. In the past one year, suicidal ideation was found in 118 (35.6%) students. Forty-six (13.9%) of all the students had made a plan in their life time to commit suicide while 16 (4.8%) of the 331 students tried to commit suicide at some point of time in their life. More females than males pondered suicide while first year medical students formed the majority of those with suicidal ideation. The single greatest risk factor predisposing to suicidal ideation was substance abuse. This was followed jointly by parental neglect and previous psychiatric disorder. Campaigns against substance abuse and counseling of vulnerable students will help in eradicating suicidal intent.

A positive association between anxiety disorders and cannabis use or cannabis use disorders in the general population--a meta-analysis of 31 studies

BACKGROUND

The aim of the current study was to investigate the association between anxiety and cannabis use/cannabis use disorders in the general population.

METHODS

A total of N = 267 studies were identified from a systematic literature search (any time- March 2013) of Medline and PsycInfo databases, and a hand search. The results of 31 studies (with prospective cohort or cross-sectional designs using non-institutionalised cases) were analysed using a random-effects meta-analysis with the inverse variance weights. Lifetime or past 12-month cannabis use, anxiety symptoms, and cannabis use disorders (CUD; dependence and/or abuse/harmful use) were classified according to DSM/ICD criteria or scores on standardised scales.

RESULTS

There was a small positive association between anxiety and either cannabis use (OR = 1.24, 95% CI: 1.06-1.45, p = .006; N = 15 studies) or CUD (OR = 1.68, 95% CI: 1.23-2.31, p = .001; N = 13 studies), and between comorbid anxiety + depression and cannabis use (OR = 1.68, 95% CI: 1.17-2.40, p = .004; N = 5 studies). The positive associations between anxiety and cannabis use (or CUD) were present in subgroups of studies with ORs adjusted for possible confounders (substance use, psychiatric illness, demographics) and in studies with clinical diagnoses of anxiety. Cannabis use at baseline was significantly associated with anxiety at follow-up in N = 5 studies adjusted for confounders (OR = 1.28, 95% CI: 1.06-1.54, p = .01). The opposite relationship was investigated in only one study. There was little evidence for publication bias.

CONCLUSION

Anxiety is positively associated with cannabis use or CUD in cohorts drawn from some 112,000 non-institutionalised members of the general population of 10 countries.

Predictors of alcohol and drug dependence

OBJECTIVE

Our study sought to identify sociodemographic, clinical, life perception, and service use characteristics that distinguish new cases of people dependent on substances from the general population; and to determine predictors of substance dependence over a 2-year period. Variables that differentiate people dependent on substances according to sex and age were also assessed.

METHODS

Among 2434 people who took part in an epidemiologic catchment area health survey at baseline, 2.2% were identified with substance dependence at the second measurement time only. Using a comprehensive framework, various aspects were considered as predictors for multivariate statistics.

RESULTS

Participants with substance dependence at time 2 only showed worse clinical conditions, life events, life and health perception, and neighbourhood characteristics than other participants, but only 2.5% used health care services. Male sex, younger age, stigmatization, and impulsiveness were predictors of substance dependence. Regarding sex, females with dependence were only more likely to suffer from social phobia than males. In terms of age categories, participants over 50 with substance dependence were more likely to have a lower household income and less social support than younger people.

CONCLUSION

Stigmatization was the strongest predictor of substance dependence. Our study also confirmed that males and younger people were more likely to have substance dependence. Anti-stigmatization, prevention, and outreach programs are needed to overcome the reluctance of this clientele to use health care services. Health professionals should also pay more attention to life and health perception and neighbourhood characteristics of newly identified drug users.

Integrated treatment of substance use and psychiatric disorders

Epidemiological studies find that psychiatric disorders, including mental disorders and substance use disorders, are common among adults and highly comorbid. Integrated treatment refers to the focus of treatment on two or more conditions and to the use of multiple treatments such as the combination of psychotherapy and pharmacotherapy. Integrated treatment for comorbidity has been found to be consistently superior compared to treatment of individual disorders with separate treatment plans. This article focuses on a review of the risks for developing comorbid disorders and the combinations of treatments that appear to be most effective for clients with particular comorbid disorders.

Chronic adolescent exposure to delta-9-tetrahydrocannabinol in COMT mutant mice: impact on indices of dopaminergic, endocannabinoid and GABAergic pathways

Cannabis use confers a two-fold increase in risk for psychosis, with adolescent use conferring an even greater risk. A high-low activity polymorphism in catechol-O-methyltransferase (COMT), a gene encoding the COMT enzyme involved in dopamine clearance in the brain, may interact with adolescent cannabis exposure to increase risk for schizophrenia. The impact of such an interaction on central neurotransmitter pathways implicated in schizophrenia is unknown. Male mice with knockout of the COMT gene were treated chronically with delta-9-tetrahydrocannabinol (THC) during adolescence (postnatal day 32-52). We measured the size and density of GABAergic cells and the protein expression of cannabinoid receptor 1 (CB1R) in the prefrontal cortex (PFC) and hippocampus (HPC) in knockout mice relative to heterozygous mutants and wild-type controls. Size and density of dopaminergic neurons was also assessed in the ventral tegmental area (VTA) across the genotypes. COMT genotype × THC treatment interactions were observed for: (1) dopaminergic cell size in the VTA, (2) CB1R protein expression in the HPC, and (3) parvalbumin (PV) cell size in the PFC. No effects of adolescent THC treatment were observed for PV and dopaminergic cell density across the COMT genotypes. COMT genotype modulates the effects of chronic THC administration during adolescence on indices of neurotransmitter function in the brain. These findings illuminate how COMT deletion and adolescent cannabis use can interact to modulate the function of neurotransmitters systems implicated in schizophrenia.

Treatment of substance abusing patients with comorbid psychiatric disorders

OBJECTIVE

To update clinicians on the latest in evidence-based treatments for substance use disorders (SUD) and non-substance use disorders among adults and suggest how these treatments can be combined into an evidence-based process that enhances treatment effectiveness in comorbid patients.

METHOD

Articles were extracted from Pubmed using the search terms "dual diagnosis," "comorbidity" and "co-occurring" and were reviewed for evidence of effectiveness for pharmacologic and psychotherapeutic treatments of comorbidity.

RESULTS

Twenty-four research reviews and 43 research trials were reviewed. The preponderance of the evidence suggests that antidepressants prescribed to improve substance-related symptoms among patients with mood and anxiety disorders are either not highly effective or involve risk due to high side-effect profiles or toxicity. Second generation antipsychotics are more effective for treatment of schizophrenia and comorbid substance abuse and current evidence suggests clozapine, olanzapine and risperidone are among the best. Clozapine appears to be the most effective of the antipsychotics for reducing alcohol, cocaine and cannabis abuse among patients with schizophrenia. Motivational interviewing has robust support as a highly effective psychotherapy for establishing a therapeutic alliance. This finding is critical since retention in treatment is essential for maintaining effectiveness. Highly structured therapy programs that integrate intensive outpatient treatments, case management services and behavioral therapies such as Contingency Management (CM) are most effective for treatment of severe comorbid conditions.

CONCLUSIONS

Creative combinations of psychotherapies, behavioral and pharmacological interventions offer the most effective treatment for comorbidity. Intensity of treatment must be increased for severe comorbid conditions such as the schizophrenia/cannabis dependence comorbidity due to the limitations of pharmacological treatments.