Cannabis use and age at onset of symptoms in subjects at clinical high risk for psychosis

Cannabis use influences disorganized symptoms severity but not transition in a cohort of non-help-seeking individuals at-risk for psychosis from São Paulo, Brazil

BACKGROUND

Cannabis use is associated with an increased risk of developing a psychotic disorder. However, in individuals with at-risk mental states for psychosis (ARMS) this association is not clear, as well as the impact of cannabis use on symptom severity. The objective of this study was to evaluate the association of cannabis use patterns and ARMS risk status, transition to psychotic and psychiatric disorders, and psychopathology.

METHOD

A sample of 109 ARMS and 197 control individuals was drawn from the general population. Lifetime, maximum and current amount of cannabis use were assessed with the South Westminster modified questionnaire. Participants were followed-up for a mean of 2.5 years and reassessed for transition to any psychiatric disorder.

RESULTS

There were no differences between ARMS and controls regarding lifetime use, current amount of use, or maximum amount of cannabis use. There were also no differences between those who transitioned to a psychiatric disorder and those who did not regarding cannabis use variables. In ARMS individuals, cannabis use was significantly related to disorganization symptoms.

CONCLUSION

The results of this study suggest that cannabis plays a role in the psychopathology of ARMS individuals, leading to more severe symptomatology.

Assessing evidence supporting cannabis harm reduction practices for adolescents at clinical high-risk for psychosis: a review and clinical implementation tool

Cannabis use is consistently associated with both increased incidence of frank psychotic disorders and acute exacerbations of psychotic symptoms in healthy individuals and people with psychosis spectrum disorders. Although there is uncertainty around causality, cannabis use may be one of a few modifiable risk factors for conversion to psychotic disorders in individuals with Clinical High Risk for Psychosis (CHR-P) syndromes, characterized by functionally impairing and distressing subthreshold psychotic symptoms. To date, few recommendations beyond abstinence to reduce adverse psychiatric events associated with cannabis use have been made. This narrative review synthesizes existing scientific literature on cannabis' acute psychotomimetic effects and epidemiological associations with psychotic disorders in both CHR-P and healthy individuals to bridge the gap between scientific knowledge and practical mental health intervention. There is compelling evidence for cannabis acutely exacerbating psychotic symptoms in CHR-P, but its impact on conversion to psychotic disorder is unclear. Current evidence supports a harm reduction approach in reducing frequency of acute psychotic-like experiences, though whether such interventions decrease CHR-P individuals' risk of conversion to psychotic disorder remains unknown. Specific recommendations include reducing frequency of use, lowering delta-9-tetrahydrocannabinol content in favor of cannabidiol-only products, avoiding products with inconsistent potency like edibles, enhancing patient-provider communication about cannabis use and psychotic-like experiences, and utilizing a collaborative and individualized therapeutic approach. Despite uncertainty surrounding cannabis' causal association with psychotic disorders, cautious attempts to reduce acute psychosis risk may benefit CHR-P individuals uninterested in abstinence. Further research is needed to clarify practices associated with minimization of cannabis-related psychosis risk.

Influence of cannabis use on incidence of psychosis in people at clinical high risk

AIMS

Evidence for case-control studies suggests that cannabis use is a risk factor for the development of psychosis. However, there have been limited prospective studies and the direction of this association remains controversial. The primary aim of the present study was to examine the association between cannabis use and the incidence of psychotic disorders in people at clinical high risk of psychosis. Secondary aims were to assess associations between cannabis use and the persistence of psychotic symptoms, and with functional outcome.

METHODS

Current and previous cannabis use were assessed in individuals at clinical high risk of psychosis (n = 334) and healthy controls (n = 67), using a modified version of the Cannabis Experience Questionnaire. Participants were assessed at baseline and followed up for 2 years. Transition to psychosis and persistence of psychotic symptoms were assessed using the Comprehensive Assessment of At-Risk Mental States criteria. Level of functioning at follow up was assessed using the Global Assessment of Functioning disability scale.

RESULTS

During follow up, 16.2% of the clinical high-risk sample developed psychosis. Of those who did not become psychotic, 51.4% had persistent symptoms and 48.6% were in remission. There was no significant association between any measure of cannabis use at baseline and either transition to psychosis, the persistence of symptoms, or functional outcome.

CONCLUSIONS

These findings contrast with epidemiological data that suggest that cannabis use increases the risk of psychotic disorder.

The CannTeen Study: Cannabis use disorder, depression, anxiety, and psychotic-like symptoms in adolescent and adult cannabis users and age-matched controls

BACKGROUND

Adolescence is characterised by psychological and neural development. Cannabis harms may be accentuated during adolescence. We hypothesised that adolescents would be more vulnerable to the associations between cannabis use and mental health and addiction problems than adults.

METHOD

As part of the 'CannTeen' study, we conducted a cross-sectional analysis. There were 274 participants: split into groups of adolescent users (n = 76; 16-17 years old) and controls (n = 63), and adult users (n = 71; 26-29 years old) and controls (n = 64). Among users, cannabis use frequency ranged from 1 to 7 days/week, while controls had 0-10 lifetime exposures to cannabis. Adolescent and adult cannabis users were matched on cannabis use frequency (mean=4 days/week). We measured Diagnostic and Statistical Manual (DSM-5) Cannabis Use Disorder (CUD), Beck Depression Inventory, Beck Anxiety Inventory and Psychotomimetic States Inventory-adapted.

RESULTS

After adjustment for covariates, adolescent users were more likely to have severe CUD than adult users (odd ratio = 3.474, 95% confidence interval (CI) = 1.501-8.036). Users reported greater psychotic-like symptoms than controls (b = 6.004, 95% CI = 1.211-10.796) and adolescents reported greater psychotic-like symptoms than adults (b = 5.509, 95% CI = 1.070-9.947). User-group was not associated with depression or anxiety. No significant interactions between age-group and user-group were identified. Exploratory analyses suggested that cannabis users with severe CUD had greater depression and anxiety levels than cannabis users without severe CUD.

CONCLUSION

Adolescent cannabis users are more likely than adult cannabis users to have severe CUD. Adolescent cannabis users have greater psychotic-like symptoms than adult cannabis users and adolescent controls, through an additive effect. There was no evidence of an amplified vulnerability to cannabis-related increases in subclinical depression, anxiety or psychotic-like symptoms in adolescence. However, poorer mental health was associated with the presence of severe CUD.

Variations of cannabis-related adverse mental health and addiction outcomes across adolescence and adulthood: A scoping review

Introduction

Evidence supporting associations between cannabis use and many health outcomes is growing, however it remains unclear how such associations vary across the lifespan. We therefore aim to answer the following questions: (1) Are the risks of cannabis's adverse effects on mental health and addiction-related outcomes different in adolescents than in adults? (2) What are the relationships between these cannabis's adverse effects and (a) an individual's age at first cannabis use, (b) age at assessment, and (c) duration of cannabis use?

Methods

We searched Medline, Embase, CINAHL, and PsychINFO from inception to 18 October 2021. Two reviewers independently screened studies and descriptively synthesized results.

Results

We included 140 studies. Cannabis effects on mental health and addiction-related outcomes were worse in adolescents, early cannabis initiators and cannabis users who consumed for longest periods. Evidence of worse long-term adverse effects in adolescents was substantial for psychosis, cannabis, and nicotine use disorders; mixed for depression, suicidality, other substance use and disorders; and limited for anxiety. Additionally, acute cannabis exposure had the opposite trend with adults more often reporting adverse effects than adolescents.

Conclusion

The available evidence suggests that cannabis use should be delayed as late as possible in adulthood and shortened in duration across the lifespan to decrease the risk of negative outcomes, while emphasizing the need for adapted harm reduction approaches. This scoping review provides evidence on the role of age and duration of exposure as determinants of cannabis-related adverse effects, which may inform prevention and harm reduction strategies.

Systematic review registration

https://doi.org/10.17605/OSF.IO/BYG72.

Cannabis use and attenuated positive and negative symptoms in youth at clinical high risk for psychosis

Cannabis use is more prevalent among youth at clinical high-risk (CHR) for psychosis than healthy controls (HC). There is mixed evidence as to whether cannabis use is associated with increased severity of attenuated psychotic symptoms (APS) or whether current cannabis use is associated with the transition to psychosis. This study aims to assess cannabis use differences between CHR youth and HC and the impact of cannabis use on APS, clinical status, and transition to psychosis. Participants were from the North American Prodrome Longitudinal Study-3, a prospective longitudinal study including 710 individuals, age 12-30, meeting criteria for a psychosis risk syndrome based on the Structured Interview for Psychosis-Risk Syndromes, and 96 HC. Cannabis use, frequency, and severity of use were assessed with the Alcohol Use Scale/Drug Use Scale. Current and past cannabis use disorders were assessed with the Structured Clinical Interview for DSM-5. Compared to HC, CHR individuals reported significantly increased lifetime cannabis use, during the past six months, and at baseline; greater frequency and severity of cannabis use; and increased prevalence of cannabis use disorder. Relative to CHR youth without cannabis use, CHR cannabis users had significantly higher ratings on baseline grandiosity and lower 12-months social anhedonia. Severity of cannabis was unrelated to clinical status at 2-years, and it did not differentiate CHR individuals who transitioned to psychosis from those who did not. However, a major limitation was that the current number of CHR cannabis users was small, and survival analyses resulted in a smaller power than the 80 % recommended.

Longitudinal effects of cannabis use on attentional processes in patients with first episode of psychosis

BACKGROUND

Attention deficits have been considered to be a central characteristic of schizophrenia-spectrum disorders. However, the specific interactions with, and longitudinal effects of, cannabis use at the different stages of the disorder remain unknown. Due to the high percentage of patients who are cannabis users at the onset of the disease, our objective was to explore this relationship and how it evolves in the first three years of the disease.

METHOD

A total of 461 patients with a first episode of psychosis (FEP) and 187 healthy controls were studied. The differences between cannabis users and non-users at baseline were explored based on both sociodemographic variables and performance in neuropsychological tests of attention. The interaction between cannabis, attentional, and clinical variables was followed up at 3 years.

RESULTS

Of the 648 participants included in this study, 229 (35.34%) were cannabis users. Of them, 187 (40.6%) were patients and 42 (22.5%) were healthy controls. At baseline, control groups [cannabis users (N = 42); non-users (N = 145)] outperformed the patient groups [cannabis users (N = 187); non-users (N = 274)] in all attention tasks. Longitudinal analyses showed significant improvements in the attentional domains at 3-year follow-up, mainly in the group of patients who had never used cannabis (N = 238), followed by ex-users (N = 105), and persistent users (N = 43). At 3-year follow-up, the group of ex-users was the one that achieved scores closer to those of healthy controls.

CONCLUSION

FEP patients, both cannabis users and non-users, showed attention deficits. However, the patients who had never used cannabis fared better than cannabis users.

Molecular Alterations of the Endocannabinoid System in Psychiatric Disorders

The therapeutic benefits of the current medications for patients with psychiatric disorders contrast with a great variety of adverse effects. The endocannabinoid system (ECS) components have gained high interest as potential new targets for treating psychiatry diseases because of their neuromodulator role, which is essential to understanding the regulation of many brain functions. This article reviewed the molecular alterations in ECS occurring in different psychiatric conditions. The methods used to identify alterations in the ECS were also described. We used a translational approach. The animal models reproducing some behavioral and/or neurochemical aspects of psychiatric disorders and the molecular alterations in clinical studies in post-mortem brain tissue or peripheral tissues were analyzed. This article reviewed the most relevant ECS changes in prevalent psychiatric diseases such as mood disorders, schizophrenia, autism, attentional deficit, eating disorders (ED), and addiction. The review concludes that clinical research studies are urgently needed for two different purposes: (1) To identify alterations of the ECS components potentially useful as new biomarkers relating to a specific disease or condition, and (2) to design new therapeutic targets based on the specific alterations found to improve the pharmacological treatment in psychiatry.

Lifetime Cannabis Use Is Not Associated With Negative Beliefs About Medication in Patients With First Treatment Psychosis

OBJECTIVE

Cannabis use is common among patients with psychosis, and along with negative beliefs about medication, it has been found to predict poor adherence to antipsychotic drug treatment. Such lack of adherence to antipsychotic drug treatment increases the risk of poor clinical outcomes and relapse in patients with first treatment for psychosis (FTP). However, to date, it is unclear whether cannabis use may be related to negative perceptions about antipsychotic drug treatment.

METHODS

A cross-sectional sample of 265 FTP patients with schizophrenia spectrum disorder underwent extensive clinical assessments. Three measures of cannabis use were obtained: lifetime, current and meeting diagnostic criteria for abuse or addiction. For the primary analyses we focused on lifetime cannabis use. The Beliefs about Medication Questionnaire (BMQ) was employed to assess the patients' specific concerns and perceptions of antipsychotic medications, as well as general beliefs about pharmacotherapy. The relationship between lifetime cannabis use and BMQ scores was investigated with general linear model (GLM) analyses, controlling for age and sex.

RESULTS

Patients with lifetime use of cannabis ≥10 times were more likely to be male, younger at the age of onset of psychosis and with higher levels of alcohol use and daily tobacco smoking, as compared to the non-users (p < 0.05). Neither lifetime use of cannabis, current use nor a cannabis abuse diagnosis was associated with negative beliefs about medicines as measured by the BMQ questionnaire.

CONCLUSION

Use of cannabis is not linked to negative perceptions about antipsychotic medicines in patients with FTP. Other reasons for poor compliance to antipsychotic drug treatment in cannabis users need to be further investigated.

Short-term functional outcome in psychotic patients: results of the Turku early psychosis study (TEPS)

BACKGROUND

Functional recovery of patients with clinical and subclinical psychosis is associated with clinical, neuropsychological and developmental factors. Less is known about how these factors predict functional outcomes in the same models. We investigated functional outcomes and their predictors in patients with first-episode psychosis (FEP) or a confirmed or nonconfirmed clinical high risk of psychosis (CHR-P vs. CHR-N).

METHODS

Altogether, 130 patients with FEP, 60 patients with CHR-P and 47 patients with CHR-N were recruited and extensively examined at baseline (T0) and 9 (T1) and 18 (T2) months later. Global Assessment of Functioning (GAF) at T0, T1 and T2 and psychotic, depression, and anxiety symptoms at T1 and T2 were assessed. Functional outcomes were predicted using multivariate repeated ANOVA.

RESULTS

During follow-up, the GAF score improved significantly in patients with FEP and CHR-P but not in patients with CHR-N. A single marital status, low basic education level, poor work situation, disorganization symptoms, perceptual deficits, and poor premorbid adjustment in patients with FEP, disorganization symptoms and poor premorbid adjustment in patients with CHR-P, and a low basic education level, poor work situation and general symptoms in patients with CHR-N predicted poor functional outcomes. Psychotic symptoms at T1 in patients with FEP and psychotic and depression symptoms at T1 and anxiety symptoms at T2 in patients with CHR-P were associated with poor functioning.

CONCLUSIONS

In patients with FEP and CHR-P, poor premorbid adjustment and disorganization symptomatology are common predictors of the functional outcome, while a low education level and poor work situation predict worse functional outcomes in patients with FEP and CHR-N. Interventions aimed at improving the ability to work and study are most important in improving the functioning of patients with clinical or subclinical psychosis.

Cannabis use in individuals at clinical high-risk for psychosis: a comprehensive review

PURPOSE

The objectives of this review were to understand the prevalence of cannabis use and how cannabis is associated with transition to psychosis, symptoms, cognition, trauma and family history in clinical high risk (CHR) for psychosis individuals.

METHOD

A systematic literature review was conducted to find studies that examined cannabis use in CHR individuals, with no limitations on the geographical area, and included publications up to November 2018. Studies were screened for inclusion based on detailed criteria, and data were extracted on cannabis use and associated outcomes. A quantitative synthesis by meta-analysis was performed where appropriate, otherwise, a qualitative synthesis was conducted.

RESULTS

Overall, 36 studies met inclusion criteria with an average age of 20.1 years and 58.4% males. Prevalence of lifetime cannabis use was 48.7%, whereas current cannabis use was 25.8% and the prevalence of cannabis use disorder/abuse or dependence was 14.9% across the studies. All cannabis use results had statistically significant heterogeneity ranging from 75.7 to 92.8%. The most commonly reported association with cannabis use was transition to psychosis, although the pooled relative risk (RR) was not statistically significant (RR = 1.11, 95% confidence interval = 0.89-1.37). For all other outcomes including symptoms, cognition, trauma, and family history, the evidence was limited, and therefore, the results were synthesized qualitatively.

CONCLUSION

Almost half of CHR individuals have ever used cannabis. However, cannabis use has not been thoroughly researched regarding frequency and dose of use, and how other factors, such as symptoms, are associated with cannabis in CHR individuals.

The Changing Legal Landscape of Cannabis Use and Its Role in Youth-onset Psychosis

The rapidly changing landscape of cannabis in terms of availability, potency, and routes of administration, as well as the decrease in risk perception and changing norms, have contributed to an increase in the popularity of cannabis. Cannabis use is associated with a poorer recovery from a psychotic disorder, increasing the risk of relapse, rehospitalization, and lower social functioning. Data are mixed regarding cannabis use as a component cause of psychosis in people at risk for psychotic disorder. Care providers, parents, and schools must educate youth and adolescents about the risks of cannabis use.

[Cannabis use in subjects at ultra high risk for psychosis]

Cannabis use is widespread among people at ultra-high risk (UHR) for psychosis. The causal link as well as the temporal link between cannabis use and further occurrence of psychosis in UHR people remain inconclusive. Current science data supported an increased risk of transition to psychosis in cannabis users who are genetically predisposed to psychosis. This risk would be even greater in the presence of a family history of psychosis, in case of a strong use and an early onset use. Several models have been cited to explain the link between cannabis use and the subsequent onset of psychosis or prepsychotic states: cannabis-induced modifications of some brain structures, a dysregulation of the hypothalamic-pituitary axis and an alteration of normal neurological development via the endocannabinoid system. Cannabis represents a modifiable risk for psychosis. Current interventions aim to reduce or stop the cannabis use in order to reduce the risk of transition to psychosis.

Predictive capacity of prodromal symptoms in first-episode psychosis of recent onset

BACKGROUND

Both the nature and number of a wide range of prodromal symptoms have been related to the severity and type of psychopathology in the psychotic phase. However, at present there is an incomplete picture focused mainly on the positive pre-psychotic dimension.

AIM

To characterize the prodromal phase retrospectively, examining the number and nature of prodromal symptoms as well as their relationship with psychopathology at the onset of first-episode psychosis.

METHODS

Retrospective study of 79 patients experiencing a first-episode psychosis of less than 1 year from the onset of full-blown psychosis. All patients were evaluated with a comprehensive battery of instruments including socio-demographic and clinical questionnaire, IRAOS interview, PANSS, stressful life events scale (PERI) and WAIS/WISC (vocabulary subtest). Bivariate associations and multiple regression analysis were performed.

RESULTS

Regression models revealed that several prodromal dimensions of IRAOS (delusions, affect, language, behaviour and non-hallucinatory disturbances of perception) predicted the onset of psychosis, with positive (22.4% of the variance) and disorganized (25.6% of the variance) dimensions being the most widely explained.

CONCLUSION

In addition to attenuated positive symptoms, other symptoms such as affective, behavioural and language disturbances should also be considered in the definitions criteria of at-high-risk people.

Federated multi-site longitudinal study of at-risk mental state for psychosis in Japan

There has been recent accumulation of evidence and clinical guidance regarding the at-risk mental state (ARMS) for psychosis. However, most studies have been observational cohort and intervention studies of Western populations. To assess the validity of the ARMS concept and the transition rate to psychosis in a non-Western nation, we retrospectively combined and analyzed clinical data of individuals diagnosed with ARMS who were prospectively followed-up at three specialized clinical services for ARMS in Japan. In total, we included 309 individuals with ARMS, of whom 43 developed overt psychosis. We estimated cumulative transition rates to psychosis with the Kaplan-Meier method, obtaining rates of 12% at 12, 16% at 24, 19% at 36, and 20% at 48 months. Only two individuals reported past cannabis use. Despite several differences among the three sites, transition rates did not differ among them. Furthermore, the transition rate of children aged between 14 and 17 years did not differ from that of individuals aged 18 years or older. Regression analysis revealed that meeting the brief limited intermittent psychotic symptoms (BLIPS) criterion was associated with an increased risk of transition to psychosis, whereas genetic risk factors were not. Although antipsychotic prescription was relatively frequent in this cohort, there was no evidence supporting frequent use of antipsychotics for this population. In conclusion, our findings support the assertion that the current concept of ARMS is applicable in Japan. Development of local clinical guidelines and training for clinicians is necessary to disseminate this concept to more clinical settings.

Differences in the Rates of Drug Polyconsumption and Psychiatric Comorbidity among Patients with Cocaine Use Disorders According to the Mental Health Service

Cocaine continues to be a worldwide public health concern in Europe. To improve prognosis and intervention, it is necessary to understand the characteristics of the patients who depend on the services where they receive care. The objective is to analyze the differences among patients who use cocaine and between ambulatory and residential resources to better adapt treatment. This is a descriptive, observational study of two populations of cocaine users in treatment: the ambulatory therapeutic community (ATC) and the therapeutic community (TC). The PRISM diagnostic interview was used for both groups. An analysis of both populations indicates a high prevalence of cocaine, heroin, cannabis, sedative, psychostimulant, and hallucinogen use disorders in the TC population compared to the ATC. In alcohol use disorder, differences between both mental health services were not observed. The degree of severity of cocaine use disorders (CUD) is greater in the TC population. The prevalence of psychiatric comorbidity is not statistically significant between the two populations, except for primary psychotic disorders, which are more prevalent in the TC population. This difference in the prevalence of psychotic disorders may be related to the high prevalence of cannabis use disorders in TC patients. Differences in the prevalence of substance use disorders, severity of CUD, and psychiatric comorbidity may limit the efficiency of mental health services involved in substance use disorder therapeutics. These results suggest the need for careful and extensive phenotyping of patients to improve intervention and prognosis in a clinical resource-dependent manner.

Cannabis use and symptom severity in individuals at ultra high risk for psychosis: a meta-analysis

OBJECTIVE

We aimed to assess whether individuals at ultra high risk (UHR) for psychosis have higher rates of cannabis use and cannabis use disorders (CUDs) than non-UHR individuals and determine whether UHR cannabis users have more severe psychotic experiences than non-users.

METHOD

We conducted a meta-analysis of studies reporting cannabis use in the UHR group and/or positive or negative symptoms among UHR cannabis users and non-users. Logit event rates were calculated for cannabis use, in addition to odds ratios to assess the difference between UHR and controls. Severity of clinical symptoms in UHR cannabis users and non-users was compared using Hedges' g.

RESULTS

Thirty unique studies were included (UHR n = 4205, controls n = 667) containing data from cross-sectional and longitudinal studies, and randomised control trials. UHR individuals have high rates of current (26.7%) and lifetime (52.8%) cannabis use, and CUDs (12.8%). Lifetime use and CUDs were significantly higher than controls (lifetime OR: 2.09; CUD OR: 5.49). UHR cannabis users had higher rates of unusual thought content and suspiciousness than non-users.

CONCLUSION

Ultra high risk individuals have high rates of cannabis use and CUDs, and cannabis users had more severe positive symptoms. Targeting substance use during the UHR phase may have significant benefits to an individual's long-term outcome.

Substance use in youth at risk for psychosis

BACKGROUND

People with schizophrenia have high rates of substance use which contributes to co-morbidity and premature mortality. Some evidence suggests people at-risk for psychosis have high rates of substance use. We aimed to assess substance use in a help-seeking cohort, comparing those at-risk and not at-risk for psychosis, and to establish any relationship with clinical symptoms.

METHOD

Participants were help-seeking youth presenting to mental health services in Sydney and Melbourne. 279 (34.8%) were at-risk for psychosis, and 452 (56.4%) did not meet criteria for a psychotic disorder or risk for psychosis. The excluded individuals were made up of 59 (7.4%) young people who met criteria for a psychotic disorder and 11 (1.4%) who were unable to be evaluated. We assessed the association of substance use involvement with risk status and clinical symptoms using multivariate regression.

RESULTS

Individuals at-risk for psychosis had significantly higher tobacco, alcohol and cannabis use than those not at-risk. Multivariate analysis revealed at-risk status was significantly associated with higher alcohol involvement scores when adjusting for age and gender, but no association was found for cannabis or tobacco. At-risk status was no longer associated with alcohol involvement when cannabis or tobacco use was added into the analysis.

CONCLUSION

Tobacco smoking, alcohol consumption and cannabis use are common in help-seeking youth, particularly those at-risk for psychosis. It is important to consider co-occurring use of different substances in adolescents. Early substance misuse in this phase of illness could be targeted to improve physical and mental health in young people.

Cannabis-induced attenuated psychotic symptoms: implications for prognosis in young people at ultra-high risk for psychosis

BACKGROUND

Cannabis use shows a robust dose-dependent relationship with psychosis risk among the general population. Despite this, it has been difficult to link cannabis use with risk for transitioning to a psychotic disorder among individuals at ultra-high risk (UHR) for psychosis. The present study examined UHR transition risk as a function of cannabis use characteristics which vary substantially between individuals including age of first use, cannabis abuse severity and a history of cannabis-induced attenuated psychotic symptoms (APS).

METHOD

Participants were 190 UHR individuals (76 males) recruited at entry to treatment between 2000 and 2006. They completed a comprehensive baseline assessment including a survey of cannabis use characteristics during the period of heaviest use. Outcome was transition to a psychotic disorder, with mean time to follow-up of 5.0 years (range 2.4-8.7 years).

RESULTS

A history of cannabis abuse was reported in 58% of the sample. Of these, 26% reported a history of cannabis-induced APS. These individuals were 4.90 (95% confidence interval 1.93-12.44) times more likely to transition to a psychotic disorder (p = 0.001). Greater severity of cannabis abuse also predicted transition to psychosis (p = 0.036). However, this effect was mediated by higher abuse severity among individuals with a history of cannabis-induced APS.

CONCLUSIONS

Findings suggest that cannabis use poses risk in a subpopulation of UHR individuals who manifest cannabis-induced APS. Whether this reflects underlying genetic vulnerability requires further study. Nevertheless, findings reveal an important early marker of risk with potentially significant prognostic utility for UHR individuals.

Cognitive behavioral therapy program for cannabis use cessation in first-episode psychosis patients: study protocol for a randomized controlled trial

BACKGROUND

The high rate of cannabis use among patients with first-episode psychosis (FEP), as well as the associated negative impact on illness course and treatment outcomes, underlines the need for effective interventions in these populations. However, to date, there have been few clinical treatment trials (of pharmacological or psychological interventions) that have specifically focused on addressing comorbid cannabis use among these patients. The aim of this paper is to describe the design of a study protocol for a randomized controlled trial in which the objective is to assess the efficacy of a specific cognitive behavioral therapy program for cannabis cessation in patients with FEP compared to standard treatment (psychoeducation).

METHODS/DESIGN

This is a single-blind randomized study with 1 year of follow-up. Patients are to be randomly assigned to one of two treatments: (1) specific cognitive behavioral therapy for cannabis cessation composed of 1-hour sessions once a week for 16 weeks, in addition to pharmacological treatment scheduled by the psychiatrist, or (2) a control group (psychoeducation + pharmacological treatment) following the same format as the experimental group. Participants in both groups will be evaluated at baseline (pre-treatment), at 16 weeks (post-treatment), and at 3 and 6 months and 1 year of follow-up. The primary outcome will be that patients in the experimental group will have greater cannabis cessation than patients in the control group at post-treatment. The secondary outcome will be that the experimental group will have better clinical and functional outcomes than the control group.

DISCUSSION

This study provides the description of a clinical trial design based on specific cognitive behavioral therapy for cannabis cessation in FEP patients, aiming to improve clinical and functional outcome, as well as tackling the addictive disorder.

TRIAL REGISTRATION

NCT02319746 ClinicalTrials.gov Identifier. ClinicalTrials.gov Protocol and Results Registration System (PRS) Receipt Release Date: 15 December 2014.

[Dual Pathology in General Population of Itagüí, Colombia]

OBJECTIVES

To study the prevalence of dual diagnosis (presence of a substance use disorder and an associated mental disorder) in the general population of a small town in the department of Antioquia in Colombia, through secondary analysis of survey data on Mental Health held in this city in 2011.

METHODS

With a sample of 415 subjects, the interview Composite International Diagnostic Interview (CIDI), WHO CAPI version, was used and statistical analysis was performed using SPSS v.21.

RESULTS

The prevalence of dual diagnosis, considering that the presence of a diagnosis of mental disorder and a disorder snuff use of different substances was 7.2%. Substances with higher prevalence of use in life for individuals with dual diagnosis were alcohol (96.7%), marijuana (80.0%), cocaine and derivatives (33.3%), heroin (23.3%) and finally no prescription tranquilizers (13.3%), finding statistical association between drug use and dual diagnosis. Major depression (40%), oppositional defiant disorder (36.7%), posttraumatic stress (33.3%), specific phobia and attention deficit (26.7%) are the most prevalent disorders in individuals with dual diagnosis of this sample. Alcohol or drugs consumption and fulfilling diagnostic criteria for dual diagnosis have a significant statistical association for consumption of drugs like marijuana, cocaine, heroin and prescription medications (P<0.001), all with disparity ratios of >1.00, very high when the drug is heroin consumed (RD=38.754) or non-prescription medications (RD=29.462). A family history of disease and drug use has a high statistical association with dual diagnosis, with a higher association with a history of mental illness (P<.001; RD=3.677).

CONCLUSIONS

The study reports on the prevalence of subjects with dual diagnosis in a Colombian population. Alcohol, marijuana, cocaine and heroin are derivatives and substances mostly consumed by these patients and the most prevalent mental disorders are depression, TOD and posttraumatic stress. These findings motivate clinicians to more actively seek the presence of dual diagnosis, directing a more appropriately treatment plans.

The Effect of Changes in Cannabis Exposure on Psychotic Symptoms in Patients With Comorbid Cannabis Use Disorder

OBJECTIVE

It remains unclear whether there is an association between severity of cannabis use and psychotic symptom severity over time. Shedding light on this under-researched matter could have clinical implications for this patient group.

METHODS

This was a secondary analysis of a randomized, parallel-group, superiority, assessor-blinded trial. We followed 60 patients with dually diagnosed psychosis and cannabis use disorders from the Danish CapOpus trial, which included assessments at baseline, post-treatment (6 months) and 10 months. Cannabis use was registered by self-report assisted by timeline follow-back. Psychotic symptoms were measured using the Positive and Negative Syndrome Scale (PANSS) positive, negative, and general symptoms scores. Analyses were adjusted for potential confounders.

RESULTS

Patients were classified into four categories: minor use (0-30 joints at baseline and 0-9 joints at follow-up; n = 19), moderate use (0-30 joints at baseline and 10-196 joints at follow-up; n = 11), high (reducing) use (31-240 joints at baseline and 0-9 joints at follow-up; n = 9), and severe use (31-240 joints at baseline and 10-196 joints at follow-up; n = 21). Those with severe and persistent cannabis use (severe use group) had significantly higher scores, as compared to those with minor use, on the positive symptom (17.0, 95% CI [4.7-19.2] vs. 12.7, 95% CI [10.4-15.0], respectively, adjusted p < .009) and general symptom (37.4, 95% CI [34.0-40.8] vs. 29.8, 95% CI [26.3-33.3], respectively, adjusted p < .003) scales at follow-up. The severe use group had significantly higher scores, as compared to the moderate use group, on the negative symptom scale at follow-up (17.4, 95% CI [15.1-19.7] vs. 12.5, 95% CI [9.3-15.6], respectively, adjusted p < .02). On the other hand, patients in the high (reducing) use group demonstrated the greatest improvement in psychotic symptoms on all three measures.

CONCLUSIONS

These findings are preliminary and more research must be done to elucidate the relationship between cannabis use and psychosis. Treatment of psychosis and comorbid cannabis use disorder could in the future incorporate treatment strategies emphasising encouragement to reduce cannabis use. CapOpus is registered at clinicaltrials.gov (NCT00484302).

Cannabis use and transition to psychosis in individuals at ultra-high risk: review and meta-analysis

BACKGROUND

Previous research has established the relationship between cannabis use and psychotic disorders. Whether cannabis use is related to transition to psychosis in patients at ultra-high risk (UHR) for psychosis remains unclear. The present study aimed to review the existing evidence on the association between cannabis use and transition to psychosis in UHR samples.

METHOD

A search of PsychInfo, Embase and Medline was conducted from 1996 to August 2015. The search yielded 5559 potentially relevant articles that were selected on title and abstract. Subsequently 36 articles were screened on full text for eligibility. Two random-effects meta-analyses were performed. First, we compared transition rates to psychosis of UHR individuals with lifetime cannabis use with non-cannabis-using UHR individuals. Second, we compared transition rates of UHR individuals with a current DSM-IV cannabis abuse or dependence diagnosis with lifetime users and non-using UHR individuals.

RESULTS

We found seven prospective studies reporting on lifetime cannabis use in UHR subjects (n = 1171). Of these studies, five also examined current cannabis abuse or dependence. Lifetime cannabis use was not significantly associated with transition to psychosis [odds ratio (OR) 1.14, 95% confidence interval (CI) 0.856-1.524, p = 0.37]. A second meta-analysis yielded an OR of 1.75 (95% CI 1.135-2.710, p = 0.01), indicating a significant association between current cannabis abuse or dependence and transition to psychosis.

CONCLUSIONS

Our results show that cannabis use was only predictive of transition to psychosis in those who met criteria for cannabis abuse or dependence, tentatively suggesting a dose-response relationship between current cannabis use and transition to psychosis.

Cardiometabolic risk factors in young people at ultra-high risk for psychosis: A systematic review and meta-analysis

BACKGROUND

The physical health of people with schizophrenia is poor, and associated with increased morbidity and mortality. Unhealthy lifestyles and side-effects of antipsychotic medication contribute to cardiometabolic dysfunction. Yet it is unclear when this unhealthy profile starts. We aimed to see if people at ultra-high risk for psychosis (UHR) have increased rates of cardiometabolic risk factors.

METHOD

An electronic search of MEDLINE, PsycINFO, Embase and the Cochrane Central Register of Controlled Trials was conducted on 1st May 2015 using terms associated with the ultra-high risk state and health. Eligible studies were peer-reviewed English language research articles with populations that met at-risk diagnostic criteria and reported cardiometabolic risk factors. A meta-analysis was conducted on smoking data, the cardiometabolic risk factor that yielded the most studies.

RESULTS

Forty-seven eligible studies were identified. UHR samples had low levels of physical activity, and high rates of smoking and alcohol abuse compared with controls. No differences were found for body mass index. An overall pooled rate of smoking for UHR participants was 33% (95% CI=0.24-0.42) and significantly more UHR individuals smoked compared with controls with a pooled odds ratio of 2.3 (P<0.05; 95% CI=-1.48-3.48).

CONCLUSIONS

UHR samples display cardiometabolic risk factors which are largely modifiable. The UHR phase is an important opportunity for early intervention services to improve physical health.

Personality in male patients with substance use disorder and/or severe mental illness

Dual diagnosis (DD) is the coexistence of a substance use disorder (SUD) and severe mental illness (SMI). The aim of this study is to determine for the first time if a specific personality pattern exists for DD patients compared to those who only have SUD or SMI. The sample was composed of 102 male, 34 patients in each group (DD, SUD and SMI). DD and SMI groups included 20 schizophrenic and 14 depressed patients respectively. Cloninger's TCI-R was administered together with a structured interview of sociodemographic and clinical characteristics. All the temperament dimensions and Self-directedness provided differences among groups. The DD and SUD showed significant higher scores in Novelty Seeking regarding SMI, whereas for Harm Avoidance the SUD subjects scored lower with respect to the DD and SMI group. Persistence was significant lower for the DD and SMI groups compared to the SUD patients. The DD obtained low significant scores in Reward Dependence in relation to the SUD and Self-directedness in relation to the SUD and SMI. Our data highlight the presence of a different personality profiles among DD, SUD and SMI disorders. Taking into account the patients' personality can benefit the clinical course and minimize the DD impact.

Substance use in individuals at clinical high risk of psychosis

BACKGROUND

A series of research reports has indicated that the use of substances such as cannabis, alcohol and tobacco are higher in youth at clinical high risk (CHR) of developing psychosis than in controls. Little is known about the longitudinal trajectory of substance use, and findings on the relationship between substance use and later transition to psychosis in CHR individuals are mixed.

METHOD

At baseline and 6- and 12-month follow-ups, 735 CHR and 278 control participants completed the Alcohol and Drug Use Scale and a cannabis use questionnaire. The longitudinal trajectory of substance use was evaluated with linear mixed models.

RESULTS

CHR participants endorsed significantly higher cannabis and tobacco use severity, and lower alcohol use severity, at baseline and over a 1-year period compared with controls. CHR youth had higher lifetime prevalence and frequency of cannabis, and were significantly younger upon first use, and were more likely to use alone and during the day. Baseline substance use did not differentiate participants who later transitioned to psychosis (n = 90) from those who did not transition (n = 272). Controls had lower tobacco use than CHR participants with a prodromal progression clinical outcome and lower cannabis use than those with a psychotic clinical outcome at the 2-year assessment.

CONCLUSIONS

In CHR individuals cannabis and tobacco use is higher than in controls and this pattern persists across 1 year. Evaluation of clinical outcome may provide additional information on the longitudinal impact of substance use that cannot be detected through evaluation of transition/non-transition to psychosis alone.

Alcohol confounds relationship between cannabis misuse and psychosis conversion in a high-risk sample

OBJECTIVE

Cannabis use has been examined as a predictor of psychosis in clinical high-risk (CHR) samples, but little is known about the impact of other substances on this relationship.

METHOD

Substance use was assessed in a large sample of CHR participants (N = 370, mean age = 18.3) enrolled in the multisite North American Prodrome Longitudinal Study Phase 1 project. Three hundred and forty-one participants with cannabis use data were divided into groups: No Use (NU, N = 211); Cannabis Use without impairment (CU, N = 63); Cannabis Abuse/Dependence (CA/CD, N = 67). Participants (N = 283) were followed for ≥2 years to determine psychosis conversion.

RESULTS

Alcohol (45.3%) and cannabis (38.1%) were the most common substances. Cannabis use groups did not differ on baseline attenuated positive symptoms. Seventy-nine of 283 participants with cannabis and follow-up data converted to psychosis. Survival analysis revealed significant differences between conversion rates in the CA/CD group compared with the No Use (P = 0.031) and CU group (P = 0.027). CA/CD also significantly predicted psychosis in a regression analysis, but adjusting for alcohol use weakened this relationship.

CONCLUSION

The cannabis misuse and psychosis association was confounded by alcohol use. Non-impairing cannabis use was not related to psychosis. Results highlight the need to control for other substance use, so as to not overstate the cannabis/psychosis connection.

Neurocognitive and familial moderators of psychiatric risk in velocardiofacial (22q11.2 deletion) syndrome: a longitudinal study

BACKGROUND

Although risk for psychosis in velocardiofacial (22q11.2 deletion) syndrome (VCFS) is well established, the cognitive and familial factors that moderate that risk are poorly understood.

METHOD

A total of 75 youth with VCFS were assessed at three time points, at 3-year intervals. Time 1 (T1) psychiatric risk was assessed with the Behavior Assessment System for Children (BASC). Data reduction of BASC scores yielded avoidance-anxiety and dysregulation factors. Time 2 (T2) neuropsychological and family function and time 3 (T3) prodromal/overt psychosis were assessed. Poisson regression models tested associations between T3 positive prodromal symptoms/overt psychosis and T1 psychiatric risk, T2 cognitive and familial factors, and their interactions.

RESULTS

T1 avoidance-anxiety ratings predicted T3 prodromal/overt psychosis. T2 verbal learning scores moderated this association, such that individuals with low avoidance-anxiety scores and stronger verbal learning skills were the least likely to demonstrate prodromal/overt psychosis at T3. Low scores on a T2 visual vigilance task also predicted T3 prodromal/overt psychosis, independently of the effect of T1 avoidance-anxiety scores. T1 dysregulation scores did not predict T3 prodromal/overt psychosis in a linear manner. Instead, the association between dysregulation and prodromal/overt psychosis was amplified by T2 levels of family organization, such that individuals with low dysregulation scores and low family organization scores were the most likely to exhibit T3 prodromal/overt psychosis.

CONCLUSIONS

Significant moderators of psychiatric risk in VCFS include verbal learning skills as well as levels of family organization, carrying implications for early identification and preventative treatment of youth with VCFS at highest risk for psychosis.

The adverse health effects of synthetic cannabinoids with emphasis on psychosis-like effects

Cannabis use is associated with an increased risk of psychosis in vulnerable individuals. Cannabis containing high levels of the partial cannabinoid receptor subtype 1 (CB1) agonist tetrahydrocannabinol (THC) is associated with the induction of psychosis in susceptible subjects and with the development of schizophrenia, whereas the use of cannabis variants with relatively high levels of cannabidiol (CBD) is associated with fewer psychotic experiences. Synthetic cannabinoid receptor agonists (SCRAs) are full agonists and often more potent than THC. Moreover, in contrast to natural cannabis, SCRAs preparations contain no CBD so that these drugs may have a higher psychosis-inducing potential than cannabis. This paper reviews the general toxicity profile and the adverse effects of SCRAs with special emphasis on their psychosis-inducing risk. The review shows that, compared with the use of natural cannabis, the use of SCRAs may cause more frequent and more severe unwanted negative effects, especially in younger, inexperienced users. Psychosis and psychosis-like conditions seem to occur relatively often following the use of SCRAs, presumably due to their high potency and the absence of CBD in the preparations. Studies on the relative risk of SCRAs compared with natural cannabis to induce or evoke psychosis are urgently needed.

Cannabis and bipolar disorder: does quitting cannabis use during manic/mixed episode improve clinical/functional outcomes?

OBJECTIVE

To examine whether bipolar disorder patients who stop cannabis use during a manic/mixed episode have better clinical and functional outcomes than continued use or never use.

METHOD

Data from the European Mania in Bipolar Longitudinal Evaluation of Medication (EMBLEM), a 2-year prospective observational study in adults with a manic/mixed episode of bipolar disorder, was used. Three cannabis use groups were: current use (between 12-week and 24-month visits); no current but previous use (during first 12 weeks); and never use. Associations between cannabis use and outcomes were analyzed using regression models.

RESULTS

Of 1922 patients analyzed, 6.9% were current users, 4.6% previous users, and 88.5% never users. Clinical outcomes differed between groups (P<0.019): previous users had highest rates of remission (68.1%) and recovery (38.7%), and lowest rates of recurrence (42.1%) and relapse (29.8%). Logistic regression showed previous users had similar outcomes to never users (all P>0.05), whereas current users had lower recovery (P=0.004) and remission (P=0.014), higher recurrence (P=0.014), greater work impairment (P=0.016), and were more likely not to be living with partner (P=0.006) than never users.

CONCLUSION

Bipolar patients who stop using cannabis during manic/mixed episode have similar clinical and functional outcomes to never users, while continued use is associated with higher risk of recurrence and poorer functioning.

Substance use in people at clinical high-risk for psychosis

BACKGROUND

Some high-risk (HR) mental states for psychosis may lack diagnostic specificity and predictive value. Furthermore, psychotic-like experiences found in young populations may act not only as markers for psychosis but also for other non-psychotic psychiatric disorders. A neglected consideration in these populations is the effect of substance misuse and its role in the development of such mental states or its influence in the evolution toward full psychotic presentations. Therefore, the main aim of this study was to thoroughly describe past and current substance use profiles of HR individuals by comparing a consecutive cohort of young people at high risk referred to a population-based early intervention clinical service with a random sample of healthy volunteers (HV) recruited from the same geographical area.

METHODS

We compared alcohol and substance use profiles of sixty help-seeking HR individuals and 60 healthy volunteers (HV). In addition to identification of abuse/dependence and influence on psychotic-like experiences, differences between HR individuals and HV were assessed for gender, ethnicity, occupational status, age of lifetime first substance use, prevalence and frequency of substance use.

RESULTS

There were no cases of substance use disorder or dependence in either groups. HR individuals were significantly younger than HV when they first started to use substances (p = 0.014). The prevalence of overall HR substance use was similar to that of HV. Although HR individuals reported less cannabinoid use than HV currently (15% vs. 27%), and more in the past (40% vs. 30%), the differences were not statistically significant (p = 0.177 & 0.339 respectively). Current frequency of use was significantly higher for HR individuals than HV for alcohol (p = 0.001) and cannabinoids (p = 0.03). In this sample, only 5% of HR individuals converted to psychosis over a two-year follow-up.

CONCLUSIONS

Certain profiles of substance use could potentially play a significant part in the evolution of HR presentations. Therefore, substance use may well represent a clinical domain that requires further emphasis and more detailed consideration in future studies.

Marijuana: respiratory tract effects

Marijuana is the most commonly used drug of abuse in the USA. It is commonly abused through inhalation and therefore has effects on the lung that are similar to tobacco smoke, including increased cough, sputum production, hyperinflation, and upper lobe emphysematous changes. However, at this time, it does not appear that marijuana smoke contributes to the development of chronic obstructive pulmonary disease. Marijuana can have multiple physiologic effects such as tachycardia, peripheral vasodilatation, behavioral and emotional changes, and possible prolonged cognitive impairment. The carcinogenic effects of marijuana are unclear at this time. Studies are mixed on the ability of marijuana smoke to increase the risk for head and neck squamous cell carcinoma, lung cancer, prostate cancer, and cervical cancer. Some studies show that marijuana is protective for development of malignancy. Marijuana smoke has been shown to have an inhibitory effect on the immune system. Components of cannabis are under investigation as treatment for autoimmune diseases and malignancy. As marijuana becomes legalized in many states for medical and recreational use, other forms of tetrahydrocannabinol (THC) have been developed, such as food products and beverages. As most research on marijuana at this time has been on whole marijuana smoke, rather than THC, it is difficult to determine if the currently available data is applicable to these newer products.

The effect of drug use on the age at onset of psychotic disorders in an Australian cohort

BACKGROUND

We aimed to examine the association between illicit substance use and age at onset in psychotic disorders in an Australian cohort.

METHODS

Retrospectively acquired information on substance use during the year prior to illness onset was collected from 1642 participants enrolled in the Australian National 2010 Survey of High Impact Psychosis study (SHIP), with an ICD-10 diagnosis of schizophrenia spectrum or affective psychosis. Latent class analysis was performed according to illicit substance use, using age as an active covariate; identified classes were subsequently validated. Cox regression was used to examine the independent contribution of the identified substance use classes and several confounding variables to the prediction of age at onset of psychosis.

RESULTS

Three classes according to substance use were identified: non-users (n=803), cannabis predominant users (n=582), and polysubstance users (n=257). For participants with schizophrenia spectrum disorders, cannabis predominant users had a higher hazard of earlier age at onset than for non-users (adjusted HR=1.38, 95% CI=1.2-1.6); polysubstance users had an even higher hazard (adjusted HR=1.95, 95% CI=1.5-2.4). In contrast, for participants with affective psychosis, cannabis predominant users (adjusted HR=1.10, 95% CI=0.8-1.4) and polysubstance users (adjusted HR=0.87, 95% CI=0.6-1.3) did not have a higher hazard of earlier age at onset compared with non-users.

CONCLUSIONS

Illicit substance use in the 12 months prior to psychosis onset has a differential effect on age at onset in schizophrenia spectrum and affective psychotic disorders. Our findings are compatible with the notion that illicit drugs bring forward age at onset in schizophrenia spectrum disorders but not affective psychotic disorders.

Substance use in clinical high risk for psychosis: a review of the literature

AIM

In the literature, there is evidence suggesting an association between substance use and psychosis. However, little is known about substance use in those who may be in the pre-psychotic phase, that is, those who are putatively prodromal are considered to be at clinical high risk (CHR) of developing psychosis.

METHODS

We conducted a review of publications measuring patterns and rates of substance use in CHR for psychosis individuals and the effects on the transition to psychosis.

RESULTS

Of 5527 potentially relevant research papers, 10 met inclusion criteria of CHR subjects and specifically mentioned substance use in the sample. The results of these studies varied. Cannabis, alcohol and tobacco/nicotine were reported as the most commonly used substances. There was limited information on the changes in patterns of use over time. Two out of the ten studies found a significant association between the use of substances and subsequent transition to psychosis. In one of these studies, substance abuse was a predictor of psychosis when included as a variable in a prediction algorithm. In the other study, the abuse of cannabis and nicotine was associated with transition to psychosis.

CONCLUSIONS

We found limited evidence to suggest that increased rates of substance use may be associated with transition to psychosis. However, further prospective research examining the association between substance use and transition to psychosis is required before any firm conclusions can be made.

Impact of Cannabis Use on the Development of Psychotic Disorders

The link between cannabis use and psychosis comprises three distinct relationships: acute psychosis associated with cannabis intoxication, acute psychosis that lasts beyond the period of acute intoxication, and persistent psychosis not time-locked to exposure. Experimental studies reveal that cannabis, tetrahydrocannabinol (THC) and synthetic cannabinoids reliably produce transient positive, negative, and cognitive symptoms in healthy volunteers. Case-studies indicate that cannabinoids can induce acute psychosis which lasts beyond the period of acute intoxication but resolves within a month. Exposure to cannabis in adolescence is associated with a risk for later psychotic disorder in adulthood; this association is consistent, temporally related, shows a dose-response, and is biologically plausible. However, cannabis is neither necessary nor sufficient to cause a persistent psychotic disorder. More likely it is a component cause that interacts with other factors to result in psychosis. The link between cannabis and psychosis is moderated by age at onset of cannabis use, childhood abuse and genetic vulnerability. While more research is needed to better characterize the relationship between cannabinoid use and the onset and persistence of psychosis, clinicians should be mindful of the potential risk of psychosis especially in vulnerable populations, including adolescents and those with a psychosis diathesis.

Is prevention a realistic goal for schizophrenia?

Over the past 2 decades, increased efforts have focused on identifying those at genetic or clinical risk for psychosis and promoting interventions that may alter the onset or trajectory of schizophrenia. We review studies published between 2010-2013 that: (1) investigate at-risk states for psychosis in larger epidemiological studies; (2) identify causes of certain clinical presentations of the schizophrenia phenotype and (3) investigate focused and multidisciplinary approaches to treat early clinical symptoms. The article places these recent studies within the context of prior research and the concept of potential measures to prevent or ameliorate the onset of psychosis.

Change in cannabis use, clinical symptoms and social functioning among patients with first-episode psychosis: a 5-year follow-up study of patients in the OPUS trial

BACKGROUND

Several studies indicate that cannabis use among patients with psychotic disorders is associated with worse outcome, but only a few studies have controlled for baseline condition and medication.

METHOD

At 5-year follow-up, interviews were carried out with 314 first-episode psychosis patients included in the OPUS trial. The patients included were in the age range of 18 to 45 years old and 59% were male. Cannabis use was extracted from the Schedule for Clinical Assessment in Neuropsychiatry. At follow-up, the patients were divided into different groups according to the variable cannabis use: abstainers, stoppers, starters and continuers. Psychotic, negative and disorganized dimensions (ranging from zero to five) were calculated for each of the four groups based on the Schedule for the Assessment of Positive and Negative Symptoms in Schizophrenia.

RESULTS

Cannabis users were younger (24.6 years v. 27.4 years, p < 0.001) and had a lower level of education. At the 5-year follow-up, users of cannabis had higher scores on the psychotic dimension [difference 0.97, 95% confidence interval (CI) 0.41-1.53, p = 0.001] and lower levels of the Global Assessment of Functioning (difference 8.26, 95% CI 2.13-14.39, p = 0.01). Those who stopped using cannabis between entry and 5-year follow-up had a significantly lower level of psychotic symptoms at 5-year follow-up even after controlling for baseline level of psychotic symptoms and for insufficient antipsychotic medication (adjusted difference in psychotic dimension -1.04, 95% CI -1.77 to -0.31, p = 0.006).

CONCLUSIONS

Continuous cannabis use was associated with higher levels of psychotic symptoms after 5 years, and this association was only partly explained by insufficient antipsychotic medication.

Gone to Pot - A Review of the Association between Cannabis and Psychosis

Cannabis is the most commonly used illicit drug worldwide, with ~5 million daily users worldwide. Emerging evidence supports a number of associations between cannabis and psychosis/psychotic disorders, including schizophrenia. These associations-based on case-studies, surveys, epidemiological studies, and experimental studies indicate that cannabinoids can produce acute, transient effects; acute, persistent effects; and delayed, persistent effects that recapitulate the psychopathology and psychophysiology seen in schizophrenia. Acute exposure to both cannabis and synthetic cannabinoids (Spice/K2) can produce a full range of transient psychotomimetic symptoms, cognitive deficits, and psychophysiological abnormalities that bear a striking resemblance to symptoms of schizophrenia. In individuals with an established psychotic disorder, cannabinoids can exacerbate symptoms, trigger relapse, and have negative consequences on the course of the illness. Several factors appear to moderate these associations, including family history, genetic factors, history of childhood abuse, and the age at onset of cannabis use. Exposure to cannabinoids in adolescence confers a higher risk for psychosis outcomes in later life and the risk is dose-related. Individuals with polymorphisms of COMT and AKT1 genes may be at increased risk for psychotic disorders in association with cannabinoids, as are individuals with a family history of psychotic disorders or a history of childhood trauma. The relationship between cannabis and schizophrenia fulfills many but not all of the standard criteria for causality, including temporality, biological gradient, biological plausibility, experimental evidence, consistency, and coherence. At the present time, the evidence indicates that cannabis may be a component cause in the emergence of psychosis, and this warrants serious consideration from the point of view of public health policy.

Effect of illness expression and liability on familial associations of clinical and subclinical psychosis phenotypes

OBJECTIVE

Given the familial influences on schizophrenia, it may be hypothesized that specific symptom domains also cluster within families, and that this applies to both clinical and subclinical levels of expression. This hypothesis was put to the test in a group of patients with a DSM-IV diagnosis of psychotic disorder together with their unaffected siblings, and a group of healthy sib-pairs.

METHOD

Subclinical positive, negative and depressive symptoms in relatives and healthy controls were assessed with the Community Assessment of Psychic Experiences (CAPE). Positive and negative schizotypy in relatives and controls was measured with the Structured Interview for Schizotypy-Revised. Multilevel linear regression analyses were conducted to investigate clustering of symptom dimensions within patient-relative sib-pairs (N = 811 pairs), healthy sib-pairs of affected families (N = 136 pairs) and healthy control sib-pairs (N = 58 pairs).

RESULTS

Familial clustering of symptoms was found in all three groups. Effect sizes were largest in healthy control sib-pairs, smallest in patient-relative sib-pairs and intermediate in healthy sib-pairs of affected families.

CONCLUSION

Studies of sibling associations in genetic studies of psychometric expression of psychosis liability need to take into account the fact that the higher levels of background genetic risk and presence of diagnosed illness are inversely associated with sibling associations.

Psychosis-inducing effects of cannabis are related to both childhood abuse and COMT genotypes

OBJECTIVE

To test whether the association between childhood abuse, cannabis use and psychotic experiences (PEs) was moderated by the COMT (catechol-O-methyltransferase) gene.

METHOD

Psychotic experiences (PEs), childhood abuse, cannabis use and COMT Val158Met genotypes were assessed in 533 individuals from the general population. Data were analysed hierarchically by means of multiple linear regression models.

RESULTS

Childhood abuse showed a significant main effect on both positive (β = 0.09; SE = 0.04; P = 0.047) and negative PEs (β = 0.11; SE = 0.05; P = 0.038). A significant three-way interaction effect was found among childhood abuse, cannabis use and the COMT gene on positive PEs (β = -0.30; SE = 0.11; P = 0.006). This result suggests that COMT genotypes and cannabis use only influenced PE scores among individuals exposed to childhood abuse. Furthermore, exposure to childhood abuse and cannabis use increased PE scores in Val carriers. However, in individuals exposed to childhood abuse but who did not use cannabis, PEs increased as a function of the Met allele copies of the COMT gene.

CONCLUSION

Cannabis use after exposure to childhood abuse may have opposite effects on the risk of PEs, depending on the COMT genotypes providing evidence for a qualitative interaction. Val carriers exposed to childhood abuse are vulnerable to the psychosis-inducing effects of cannabis.

Neurophysiologic effect of GWAS derived schizophrenia and bipolar risk variants

Genome-wide association studies (GWAS) have identified multiple single nucleotide polymorphisms (SNPs) as disease associated variants for schizophrenia (SCZ), bipolar disorder (BPD), or both. Although these results are statistically robust, the functional effects of these variants and their role in the pathophysiology of SCZ or BPD remain unclear. Dissecting the effects of risk genes on distinct domains of brain function can provide important biological insights into the mechanisms by which these genes may confer illness risk. This study used quantitative event related potentials to characterize the neurophysiological effects of well-documented GWAS-derived SCZ/BPD susceptibility variants in order to map gene effects onto important domains of brain function. We genotyped 199 patients with DSM-IV diagnoses of SCZ or BPD and 74 healthy control subjects for 19 risk SNPs derived from previous GWAS findings and tested their association with five neurophysiologic traits (P3 amplitude, P3 latency, N1 amplitude, P2 amplitude, and P50 sensory gating responses) known to be abnormal in psychosis. The TCF4 SNP rs17512836 risk allele showed a significant association with reduced auditory P3 amplitude (P = 0.00016) after correction for multiple testing. The same allele was also associated with delayed P3 latency (P = 0.005). Our results suggest that a SCZ risk variant in TCF4 is associated with neurophysiologic traits thought to index attention and working memory abnormalities in psychotic disorders. These findings suggest a mechanism by which TCF4 may contribute to the neurobiological basis of psychotic illness.

The brain effects of cannabis in healthy adolescents and in adolescents with schizophrenia: a systematic review

Cannabis is widely used in adolescence; however, the effects of cannabis on the developing brain remain unclear. Cannabis might be expected to have increased effects upon brain development and cognition during adolescence. There is extensive re-organisation of grey (GM) and white matter (WM) at this time, while the endocannabinoid (eCB) system, which is involved in the normal physiological regulation of neural transmission, is still developing. In healthy adolescent cannabis users there is a suggestion of greater memory loss and hippocampal volume changes. Functional studies point to recruitment of greater brain areas under cognitive load. Structural and DTI studies are few, and limited by comorbid drug and alcohol use. The studies of cannabis use in adolescent-onset schizophrenia (AOS) differ, with one study pointing to extensive GM and WM changes. There is an intriguing suggestion that the left parietal lobe may be more vulnerable to the effects of cannabis in AOS. As in adult schizophrenia cognition does not appear to be adversely affected in AOS following cannabis use. Given the limited number of studies it is not possible to draw firm conclusions. There is a need for adequately powered, longitudinal studies.

Does Cannabidiol Protect Against Adverse Psychological Effects of THC?

The recreational use of cannabis can have persistent adverse effects on mental health. Delta-9-tetrahydrocannabinol (THC) is the main psychoactive constituent of cannabis, and most, if not all, of the effects associated with the use of cannabis are caused by THC. Recent studies have suggested a possible protective effect of another cannabinoid, cannabidiol (CBD). A literature search was performed in the bibliographic databases PubMed, PsycINFO, and Web of Science using the keyword "cannabidiol." After removing duplicate entries, 1295 unique titles remained. Based on the titles and abstracts, an initial selection was made. The reference lists of the publications identified in this manner were examined for additional references. Cannabis is not a safe drug. Depending on how often someone uses, the age of onset, the potency of the cannabis that is used and someone's individual sensitivity, the recreational use of cannabis may cause permanent psychological disorders. Most recreational users will never be faced with such persistent mental illness, but in some individuals cannabis use leads to undesirable effects: cognitive impairment, anxiety, paranoia, and increased risks of developing chronic psychosis or drug addiction. Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC. However, the question remains of how the laboratory results translate to the types of cannabis that are encountered by real-world recreational users.

"Spiceophrenia": a systematic overview of "spice"-related psychopathological issues and a case report

OBJECTIVES

The use of synthetic cannabimimetics (SC; "spice" drugs) is increasing, especially among teenagers and young adults. In parallel with this, the number of studies describing intoxication episodes associated with psychotic symptoms in SC users is growing. We present both a systematic review of the related literature and a case report, which seems to highlight the existence of a possible association between SC use and psychosis.

METHODS

Some 223 relevant studies were here identified and reviewed. Out of these, 120 full text articles were assessed for eligibility, and 41 were finally included in the systematic review.

RESULTS

According to the available data from the studies here identified, SC's average age of users was 22.97 years, and the male/female ratio was 3.16:1. SC compounds most often reported in studies using biological specimen analysis were JWH-018, JWH-073, JWH-122, CP-47,497, and JWH-250. Mounting evidence seemed to suggest that psychotic symptoms such as hallucinations and delusions may occur in acute/chronic SC users.

CONCLUSIONS

Although a clear causal link may not be here identified, the available evidence suggests that SC can trigger the onset of acute psychosis in vulnerable individuals and/or the exacerbation of psychotic episodes in those with a previous psychiatric history.

Predictors of a clinical high risk status among individuals with a family history of psychosis

BACKGROUND

Risk for psychosis can be assessed on the basis of genetic risk, referred to in the literature as family high risk (FHR) or through the presence of clinical high risk symptoms (CHR). Recent studies have also shown that certain risk factors (i.e. trauma, cannabis, migration) may play a role in the development of psychosis, possibly in combination with one another and in particular in combination with a family history of psychosis. It is unknown which risk factors may play a role in the prediction of CHR status among individuals whom are already genetically vulnerable. This study compared FHR individuals who also met CHR criteria to FHR individuals who did not on various risk factors, psychopathology and functioning.

METHOD

Participants were 25 who met FHR and CHR criteria (FHR + CHR) as determined by Structured Interview for Prodromal Syndromes, 25 who met only FHR criteria (FHR-non-CHR), and 25 healthy controls. A binary logistic regression was performed to determine the best predictors of belonging to the FHR + CHR group.

RESULTS

FHR + CHR and FHR-non CHR were significantly different on measures of age first tried cannabis (F = 3.65, p < 0.05) and IQ (F = 3.32, p < 0.05). FHR groups also differed on self-reported anxiety (F=11.79, p < 0.001) and current scores of social (F = 19.74, p < 0.0001) and role (F = 17.71, p < 0.0001) functioning. The most significant predictor of belonging to the FHR + CHR group was an earlier age of cannabis use (OR = 0.44, p = 0.05).

CONCLUSION

These preliminary results are promising in determining potential risk factors for the development of psychosis in those who are at risk for psychosis on the basis of a family history.

Prediction of psychosis in clinical high-risk patients by the Schizotypal Personality Questionnaire. Results of the EPOS project

OBJECTIVE

Schizotypal features indicate proneness to psychosis in the general population. It is also possible that they increase transition to psychosis (TTP) among clinical high-risk patients (CHR). Our aim was to investigate whether schizotypal features predict TTP in CHR patients.

METHODS

In the EPOS (European Prediction of Psychosis Study) project, 245 young help-seeking CHR patients were prospectively followed for 18 months and their TTP was identified. At baseline, subjects were assessed with the Schizotypal Personality Questionnaire (SPQ). Associations between SPQ items and its subscales with the TTP were analysed in Cox regression analysis.

RESULTS

The SPQ subscales and items describing ideas of reference and lack of close interpersonal relationships were found to correlate significantly with TTP. The co-occurrence of these features doubled the risk of TTP.

CONCLUSIONS

Presence of ideas of reference and lack of close interpersonal relations increase the risk of full-blown psychosis among CHR patients. This co-occurrence makes the risk of psychosis very high.

Clonazepam as agonist substitution treatment for benzodiazepine dependence: a case report

Nowadays, the misuse of benzodiazepines (BZDs) is a cause for a serious concern among pharmacologically inexperienced patients, whether treated or untreated, that could lead to significant complications, including tolerance, dependence, and addiction. We present a case report in which an Italian patient affected by anxiety disorder and treated with BZDs presented a severe case of dependence on BZDs. We treated him according to an agonist substitution approach, switching from the abused BZD to a slow-onset, long-acting, high potency agonist (clonazepam), and looking at the methadone treatment model as paradigm. We decided to use clonazepam for its pharmacokinetic properties. The advantage of choosing a slow-onset, long-lasting BZD for the treatment of our patient was that it led us to a remarkable improvement in the clinical situation, including the cessation of craving, absence of withdrawal symptoms, reduced anxiety, improvements in social functioning, and a better cognition level.