Cannabis use and first-episode psychosis: relationship with manic and psychotic symptoms, and with age at presentation

The Whys and Wherefores of Reducing Cannabis Use in Early Psychosis: A Qualitative Study of Service Users' Experiences of Quitting and the Support

Objectives: Cannabis is the most widely used substance among people with recent onset psychosis, but it can have significant negative consequences for long term wellbeing in this cohort. We explored the perspectives of people with recent onset psychosis who used cannabis on their motivations for quitting, their experiences of trying to do so, and their views of the support they had received and the strategies that they had tried. Methods: Twenty one-to-one qualitative interviews were conducted with Early Intervention in Psychosis service users in England who had participated in the CIRCLE trial. Purposive sampling was used to recruit a mix of demographic, cannabis use status, and other characteristics. Results: Quitting cannabis is often very challenging for people and can require making substantial changes in their lives, including to their social relationships, living arrangements, or pathways through work or education. Participants reported wanting help, but often experienced support from mental health services as insubstantial and poorly tailored. Support from peers with relevant lived-experience, where available, was highly valued. Common reasons for quitting included its impact on key life goals or engaging with hobbies, finances, mental health, incompatibility with self-image, and negative use expectancies of intoxication. Concerns regarding mental health were primarily related to psychotic illness, including fear of exacerbating symptoms or experiencing future hospital admissions. Discussion: It is currently unclear how best to support people in this cohort. Interventions that provide support from people with relevant lived experience may be more valued and more clinically effective than current offerings.

Observed Trajectories of Cannabis Use and Concurrent Longitudinal Outcomes in Youth and Young Adults Receiving Coordinated Specialty Care for Early Psychosis

Cannabis use is present and persistent in young adults with early psychosis receiving Coordinated Specialty Care (CSC) in the United States. While CSC programs are effective in improving quality of life, helping individuals reach goals, and promoting recovery, cannabis use may limit the extent of these improvements. This study extended upon previous findings to examine trajectories of cannabis use among individuals with early psychosis. The sample consisted of 1325 CSC participants enrolled for more than one year at OnTrackNY and followed up to two years, categorized into three groups: no use, reduced use, and persistent use. Baseline demographic and clinical differences were compared across groups and associations between clinical and psychosocial outcomes at 12 months and 24 months were examined across groups. Of the sample, 40 % remained persistent users over two years while 12.8 % reduced their use. At baseline, persistent users were younger (p = 0.011), more likely to be male (p < 0.001), had lower education levels (p = 0.019), and were more likely to have had past legal issues prior to admission (p < 0.001) than non-users. At 2 years, persistent users had significantly worse symptom scores than non-users (p = 0.0003) and reduced users (p = 0.0004). These findings highlight the presence of persistent cannabis use being common in this population and the need to improve substance use treatment offered to allow more CSC participants to achieve improved outcomes.

Cannabis use and its relationship with bipolar disorder: A systematic review and meta-analysis

Cannabis use has been stated as a causal risk factor for the occurrence of schizophrenia and other psychotic disorders. There is a dearth of literature stating the association of cannabis with bipolar disorder. This review aimed to find the repercussion of cannabis use on the onset of the first episode of bipolar disorder and the worsening of the symptoms in pre-existing illness. A thorough systematic review of the existing literature was carried out using the PRISMA guidelines. PubMed, Medline, EMBASE, SCOPUS, and Google-scholar databases were searched for studies fitting our study's inclusion and exclusion criteria. A total of 25 studies were included in the systematic review and out of these 25 studies, five prospective studies met the inclusion criteria for the primary outcome meta-analysis. A total sample of 13,624 individuals was included in these five studies. A fixed effect model was used in the meta-analysis of these five studies and it revealed an association between cannabis and bipolar disorder with an effect size of 2.63 (95% CI: 1.95-3.53) (heterogeneity: chi² = 3.01, df = 3 (P = 0.39); I² = 0%). Our findings propose that cannabis use may precipitate or worsen bipolar disorder. This highlights the importance of the detrimental effect of cannabis use on bipolar disorder and the need to discourage cannabis use in the youth culture. High-quality prospective studies are required to delineate the effect of cannabis use on bipolar disorder.

A tablet-based quantitative assessment of manual dexterity for detection of early psychosis

Background

We performed a pilot study on whether tablet-based measures of manual dexterity can provide behavioral markers for detection of first-episode psychosis (FEP), and whether cortical excitability/inhibition was altered in FEP.

Methods

Behavioral and neurophysiological testing was undertaken in persons diagnosed with FEP (N = 20), schizophrenia (SCZ, N = 20), autism spectrum disorder (ASD, N = 20), and in healthy control subjects (N = 20). Five tablet tasks assessed different motor and cognitive functions: Finger Recognition for effector (finger) selection and mental rotation, Rhythm Tapping for temporal control, Sequence Tapping for control/memorization of motor sequences, Multi Finger Tapping for finger individuation, and Line Tracking for visuomotor control. Discrimination of FEP (from other groups) based on tablet-based measures was compared to discrimination through clinical neurological soft signs (NSS). Cortical excitability/inhibition, and cerebellar brain inhibition were assessed with transcranial magnetic stimulation.

Results

Compared to controls, FEP patients showed slower reaction times and higher errors in Finger Recognition, and more variability in Rhythm Tapping. Variability in Rhythm Tapping showed highest specificity for the identification of FEP patients compared to all other groups (FEP vs. ASD/SCZ/Controls; 75% sensitivity, 90% specificity, AUC = 0.83) compared to clinical NSS (95% sensitivity, 22% specificity, AUC = 0.49). Random Forest analysis confirmed FEP discrimination vs. other groups based on dexterity variables (100% sensitivity, 85% specificity, balanced accuracy = 92%). The FEP group had reduced short-latency intra-cortical inhibition (but similar excitability) compared to controls, SCZ, and ASD. Cerebellar inhibition showed a non-significant tendency to be weaker in FEP.

Conclusion

FEP patients show a distinctive pattern of dexterity impairments and weaker cortical inhibition. Easy-to-use tablet-based measures of manual dexterity capture neurological deficits in FEP and are promising markers for detection of FEP in clinical practice.

Cognitive functioning and cannabis use in first-episode psychosis

AIM

Cannabis use is common in people with psychotic disorders. However, the effect of cannabis on cognition in psychosis remains unclear. Our study investigates relationships between the history of cannabis use and cognitive performance in patients with first-episode psychosis (FEP) during a one-year follow-up.

METHODS

The present study included FEP (N = 91) and control (N = 61) groups. Cannabis use was evaluated with a self-report questionnaire, clinical assessment, and medical records during a lifetime and 12 months prior to the treatment onset (recent). Symptoms of psychosis and anxiety were evaluated on the brief psychiatric rating scale. Negative symptoms were assessed using the scale for the assessment of negative symptoms. Cognitive tests were used to evaluate neurocognition (summarized in the g factor) and social cognition. Crude regression analyses for the g factor included variables of cannabis use as independent variables. Full regression models were controlled for gender, education, and clinical symptoms.

RESULTS

In the FEP group, men used cannabis more frequently than women. In the crude regression model for FEP patients, never having used cannabis was associated with a better neurocognitive profile at 12 months. In the full model, more severe anxiety symptoms were associated with better neurocognition at two months, and less severe negative symptoms were associated with better neurocognition at 12 months. Cannabis use was not associated with social cognition. No associations between cognitive performance and cannabis use emerged in the controls.

CONCLUSION

Negative and affective symptom severity in FEP was associated with cognitive performance to a greater degree than a lifetime history of cannabis use.

Association between formal thought disorder and cannabis use: a systematic review and meta-analysis

Formal thought disorder (FTD) is a multidimensional syndrome mainly occurring along the psychosis continuum. Cannabis use is known to increase symptoms of psychosis, particularly positive symptoms. However, the impact of cannabis use on FTD in individuals presenting symptoms along the psychosis continuum remains unclear. To address this knowledge gap, we conducted a meta-analysis examining the association between cannabis use and FTD in those individuals. We hypothesized that cannabis would worsen FTD. We conducted a systematic search of the PubMed, ScienceDirect, PsycINFO, Web of Science, Embase and Google Scholar databases up to July 2022. The results were collated through a random-effects model using the statistical software R. Reference lists of included studies were searched for additional relevant publications. Nineteen studies were included, totalling 1840 cannabis users and 3351 non-cannabis users. The severity of FTD was found to be higher in cannabis users (SMD = 0.21, 95%CI [0.12–0.29], p = 0.00009). Subgroup analyses revealed that FTD severity was increased among cannabis users, regardless of the disorder severity: healthy individuals (SMD = 0.19, 95%CI [0.05–0.33], p = 0.02); patients with first-episode psychosis (SMD = 0.21, 95%CI [0.01–0.41], p = 0.04); patients with schizophrenia (SMD = 0.25, 95%CI [0.11–0.38], p = 0.005). Between-group differences were not significant. In line with its already known effect on positive symptoms in psychosis, cannabis use appears to be associated with increased FTD severity all along the psychosis continuum. Future research should consider potential confounding variables such as other substance use disorders and explore how FTD dimensions are impacted by cannabis use.

Relationship between patterns of cannabis use and functional and symptomatic trajectories in first-episode psychosis

Cannabis use is common in first-episode psychosis (FEP) but evidence is mixed about the extent to which cannabis use predicts symptoms and functional outcomes among those who seek treatment. This study sought to characterize cannabis use patterns and examine the relationship with clinical outcomes, including interactions with early intervention services (EIS). Data were drawn from the Recovery After an Initial Schizophrenia Episode-Early Treatment Program (RAISE-ETP) study including FEP individuals receiving treatment at sites randomized to provide either EIS (NAVIGATE) or community care (CC). Cannabis use was assessed monthly and symptom and functioning data were collected at baseline, 6, 12, 18, and 24 months. Among the 404 participants enrolled, 334 were classified into four cannabis use groups (consistent, sporadic, stopped, and never users) based on their use during the first year. Consistent and sporadic cannabis users were younger, whereas those who had stopped using were older. Sporadic users had the highest depression and the lowest functioning at baseline and improved less during treatment in negative emotions and intrapsychic foundations (e.g., motivation and sense of purpose) than non-users. However, sporadic users who received NAVIGATE improved more in overall symptoms and functioning than those who received CC. Consistent users did not tend to differ in their trajectories from non-users. Individuals with FEP who use cannabis sporadically showed less clinical improvement than non-users. However, EIS treatment reduced the negative effects of sporadic cannabis use on clinical outcomes. Those who use cannabis sporadically may have unique needs that require attention in EIS.

Cognitive Behavioral Therapy Program for Cannabis Use Cessation in First-Episode Psychosis Patients: A 1-Year Randomized Controlled Trial

Despite the negative influence of cannabis use on the development and prognosis of first-episode psychosis (FEP), there is little evidence on effective specific interventions for cannabis use cessation in FEP. The aim of this study was to compare the efficacy of a specific cognitive behavioral therapy (CBT) for cannabis cessation (CBT-CC) with treatment as usual (TAU) in FEP cannabis users. In this single-blind, 1-year randomized controlled trial, 65 participants were randomly assigned to CBT-CC or TAU. The primary outcome was the reduction in cannabis use severity. The CBT-CC group had a greater decrease in cannabis use severity and positive psychotic symptoms over time, and a greater improvement in functioning at post-treatment than TAU. The treatment response was also faster in the CBT-CC group, reducing cannabis use, anxiety, positive and general psychotic symptoms, and improving functioning earlier than TAU in the follow-up. Moreover, patients who stopped and/or reduced cannabis use during the follow-up, decreased psychotic symptoms and increased awareness of disease compared to those who continued using cannabis. Early intervention based on a specific CBT for cannabis cessation, may be effective in reducing cannabis use severity, in addition to improving clinical and functional outcomes of FEP cannabis users.

A systematic review of longitudinal studies investigating the impact of cannabis use in patients with psychotic disorders

Introduction: Research has established a link between cannabis use and adverse psychotic outcomes in psychosis patients. However, we have yet to determine if this relationship is maintained when controlling for important confounding variables. The following systematic review aims to investigate if the association between cannabis use and psychotic outcomes is preserved when accounting for important confounders, and if discontinued use mitigates any potential negative impacts.Areas covered: The authors conducted an exhaustive search of the MEDLINE database and Google Scholar to identify articles pertaining to the systematic review. Thirty-three articles were retained for meeting the eligibility criteria.Expert opinion: The evidence confirms an overarching pattern of negative psychotic outcomes of cannabis intake in psychosis populations, even when accounting for crucial confounders. Psychosis patients should be informed with evidence-based health information regarding the effects of cannabis use. Clinicians should systematically evaluate cannabis intake patterns in psychosis patients and offer intervention services geared toward reducing problematic consumption. Researchers should record confounding factors in a more systematic manner in future longitudinal investigations while paying careful attention to the potency and dose-response effects of the ingested cannabis. Deciders will need to investigate the impact of cannabis regulations on psychosis populations.

A latent class analysis of cannabis use products in a general population sample of adolescents and their association with paranoia, hallucinations, cognitive disorganisation and grandiosity

Adolescents have access to a wide range of cannabis products with patterns of use becoming increasingly diverse. This study aimed to identify subgroups of adolescents in the general population who use similar types of cannabis and their association with psychotic experiences. Data on cannabis use were obtained from 467 adolescents aged between 16 and 17 years. Latent class analysis (LCA) identified groups of adolescents based on the type of cannabis used in the past 12 months. Univariate analysis explored differences in socio-demographics, substance use and mental health symptoms between groups. Multivariate analysis examined associations between class membership and psychotic experiences controlling for frequency and amount of cannabis. Finally, we explored the association between motives for cannabis and class membership using multi-nominal logistic regression. LCA identified 3 classes of adolescents: (i) herbal only (47.9%); (ii) skunk only (20.8%) and (3) mixed use (31.3%). Relative to non-users, skunk only use was associated with a 2-fold increase in paranoia (OR = 2.45, 95% CI = 1.29-4.63), along with, sleep disturbance and anxiety. Monthly cannabis use and consuming 2 or more joints on one occasion was associated with a 2-fold increase in hallucinations (OR = 2.2; 95% CI = 1.0-4.8 and OR = 1.9; 95% CI = 1.2-3.2), but did not reach the Bonferroni corrected p-value. Expansion and conformity motives differentiated the mixed cannabis class from the herbal only class. The findings suggest that different subgroups of cannabis users exist in adolescence as defined by the type of cannabis consumed and are differentially related to psychotic experiences and motives for use.

Examining the association between exposome score for schizophrenia and functioning in schizophrenia, siblings, and healthy controls: Results from the EUGEI study

Background

A cumulative environmental exposure score for schizophrenia (exposome score for schizophrenia [ES-SCZ]) may provide potential utility for risk stratification and outcome prediction. Here, we investigated whether ES-SCZ was associated with functioning in patients with schizophrenia spectrum disorder, unaffected siblings, and healthy controls.

Methods

This cross-sectional sample consisted of 1,261 patients, 1,282 unaffected siblings, and 1,525 healthy controls. The Global Assessment of Functioning (GAF) scale was used to assess functioning. ES-SCZ was calculated based on our previously validated method. The association between ES-SCZ and the GAF dimensions (symptom and disability) was analyzed by applying regression models in each group (patients, siblings, and controls). Additional models included polygenic risk score for schizophrenia (PRS-SCZ) as a covariate.

Results

ES-SCZ was associated with the GAF dimensions in patients (symptom: B = −1.53, p-value = 0.001; disability: B = −1.44, p-value = 0.001), siblings (symptom: B = −3.07, p-value < 0.001; disability: B = −2.52, p-value < 0.001), and healthy controls (symptom: B = −1.50, p-value < 0.001; disability: B = −1.31, p-value < 0.001). The results remained the same after adjusting for PRS-SCZ. The degree of associations of ES-SCZ with both symptom and disability dimensions were higher in unaffected siblings than in patients and controls. By analyzing an independent dataset (the Genetic Risk and Outcome of Psychosis study), we replicated the results observed in the patient group.

Conclusions

Our findings suggest that ES-SCZ shows promise for enhancing risk prediction and stratification in research practice. From a clinical perspective, ES-SCZ may aid in efforts of clinical characterization, operationalizing transdiagnostic clinical staging models, and personalizing clinical management.

General Functioning in Patients With First-Episode Psychosis After the First 18 Months of Treatment

BACKGROUND

One of the main goals in the treatment of first-episode psychosis (FEP) is achieving functional remission. This study aims to analyze whether initial neurocognitive status and the use of specific pharmacological and psychosocial treatment options in FEP can predict general functioning after 18 months of treatment.

METHODS

We conducted a longitudinal naturalistic study with a sample of 129 patients with FEP treated at 2 Croatian psychiatric clinics from 2016until 2018. Ordinal regression was used to predict the global level of functioning assessed with the Global Assessment of Functioning scale (GAF) at the 18th month of treatment from the baseline symptoms (assessed with a set of neurocognitive tests) and different treatment options.

RESULTS

Higher score on GAF at the 18th month was significantly predicted by female sex, better baseline verbal memory and GAF scores, and the type of treatment. Group multimodal psychosocial treatment, antipsychotic polytherapy, and not being treated with sedatives at baseline predicted better GAF scores at follow-up. In the exploratory analysis, taking sedatives in the final assessment and being rehospitalized due to relapse predicted worse GAF scores at the end of follow-up.

CONCLUSIONS

Although baseline neurocognitive features and baseline general functioning seem to influence the overall long-term functioning of persons with FEP, addition of a multimodal group psychosocial treatment program and appropriate medication seem to be equally important for improving the patients' level of functioning after the FEP.

Clinical Investigation on the Impact of Cannabis Abuse on Thyroid Hormones and Associated Psychiatric Manifestations in the Male Population

Cannabis abuse is a common public health issue and may lead to considerable adverse effects. Along with other effects, the dependence on cannabis consumption is a serious problem which has significant consequences on biochemical and clinical symptoms. This study intends to evaluate the harmful effects of the use of cannabis on thyroid hormonal levels, cardiovascular indicators, and psychotic symptoms in the included patients. This prospective multicenter study was conducted on cannabis-dependent patients with psychotic symptoms (n = 40) vs. healthy control subjects (n = 40). All participants were evaluated for psychiatric, biochemical, and cardiovascular physiological effects. Patients were selected through Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria and urine samples, exclusively for the evaluation of cannabis presence. Serum thyroid stimulating hormone (TSH), T3, and T4 levels were measured using the immunoassay technique. Patients were assessed for severity of depressive, schizophrenic, and manic symptoms using international ranking scales. Various quantifiable factors were also measured for the development of tolerance by cannabis. Among the patients of cannabis abuse, 47.5% were found with schizophrenia, 20% with schizoaffective symptoms, 10% with manic symptoms, and 22.5% with both manic and psychotic symptoms. In the group-group and within-group statistical analysis, the results of thyroid hormones and cardiovascular parameters were non-significant. The psychiatric assessment has shown highly significant (p < 0.001) difference of positive, negative, general psychopathology, and total scores [through Positive and Negative Syndrome Scale (PANSS) rating scales] in patients vs. the healthy control subjects. The study revealed that cannabis abuse did not significantly alter thyroid hormones and cardiovascular parameters due to the development of tolerance. However, the cannabis abuse might have a significant contributing role in the positive, negative, and manic symptoms in different psychiatric disorders.

A contingency management intervention to reduce cannabis use and time to relapse in early psychosis: the CIRCLE RCT

BACKGROUND

Cannabis is the most prevalent illicit substance among people with psychosis, and its use is associated with poorer clinical and social outcomes. However, so far, there has been limited evidence that any treatment is effective for reducing use. Contingency management (CM) is an incentive-based intervention for substance misuse that has a substantial evidence base across a range of substances and cohorts. However, to date there have been no randomised controlled trials (RCTs) of CM as a treatment for cannabis use specifically in psychosis.

OBJECTIVE

To conduct a RCT investigating the clinical effectiveness and cost-effectiveness of CM in reducing cannabis use among Early Intervention in Psychosis (EIP) service users.

DESIGN

The CIRCLE (Contingency Intervention for Reduction of Cannabis in Early Psychosis) trial was a rater-blinded, multicentre RCT with two arms. Participants were randomised 1 : 1 to either an CM arm, in which participants received CM for cannabis use alongside an optimised treatment-as-usual programme including structured psychoeducation, or a control arm in which participants received the treatment as usual only.

SETTING

EIP services across the Midlands and the south-east of England.

PARTICIPANTS

The main eligibility criteria were EIP service users with a history of psychosis, aged 18-36 years, and having used cannabis at least once per week during 12 of the previous 24 weeks.

INTERVENTION

The CM intervention offered financial incentives (i.e. shopping vouchers) for cannabis abstinence over 12 once-weekly sessions, confirmed using urinalysis. The maximum value in vouchers that participants could receive was £240.

MAIN OUTCOME MEASURES

The main outcome was time to relapse, operationalised as admission to an acute mental health service or hospital. The primary outcome was assessed at 18 months post inclusion using electronic patient records. Secondary outcomes assessed the clinical effectiveness and cost-effectiveness of the intervention, for which data were collected at 3 and 18 months.

RESULTS

A total of 278 participants were randomised to the CM arm and 273 were randomised to the control arm. In total, 530 (96%) participants were followed up for the primary outcome. There was no significant difference in time to admission between trial arms by 18 months following consent (hazard ratio 1.03, 95% confidence interval 0.76 to 1.40). There were no statistically significant differences in most secondary outcomes, including cannabis use, at either follow-up assessment. There were 58 serious adverse events, comprising 52 inpatient episodes, five deaths and one arrest.

LIMITATIONS

Participant retention was low at 18 months, limiting the assessment of secondary outcomes. A different CM intervention design or reward level may have been effective.

CONCLUSIONS

The CM intervention did not appear to be effective in reducing cannabis use and acute relapse among people with early psychosis and problematic cannabis use.

FUTURE WORK

Cannabis use is still a significant clinical concern in this population. A pressing need remains to identify suitable treatments. A wider perspective on the social circumstances of young people with psychosis may be needed for a successful intervention to be found.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN33576045.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 45. See the NIHR Journals Library website for further project information.

A Retrospective Study of the Clinical Characteristics Associated with Alcohol and Cannabis use in Early Phase Psychosis

OBJECTIVE

Alcohol and cannabis misuse are common in patients with early phase psychosis (EPP); however, research has tended to focus primarily on cannabis misuse and EPP outcomes, with a relative lack of data on alcohol misuse. This retrospective cross-sectional EPP study investigated the relationship between cannabis, alcohol, and cannabis combined with alcohol misuse, on age, gender, psychotic, depressive and anxiety symptom severity, and social/occupational functioning, at entry to service.

METHODS

Two-hundred and sixty-four EPP patients were divided into 4 groups based on substance use measured by the Alcohol, Smoking and Substance Involvement Screening Test: (1) no to low-level cannabis and alcohol misuse (LU), (2) moderate to high alcohol misuse only (AU), (3) moderate to high cannabis misuse only (CU), and (4) moderate to high alcohol and cannabis misuse (AU + CU).

RESULTS

We found significant between group differences in age (with the AU group being the oldest and AU + CU group the youngest) as well as gender (with the CU group having the highest percentage of men). There were also group differences in positive psychotic symptoms (lowest in AU group), trait anxiety (highest in AU + CU group), and social/occupational functioning (highest in AU group). Further regression analyses revealed a particularly strong relationship between AU + CU group and trait anxiety (3-fold increased odds of clinical trait anxiety for combined misuse of alcohol and cannabis compared to non/low users).

CONCLUSIONS

This study demonstrates the unique demographic and clinical characteristics found in the EPP population at entry to care associated with alcohol and cannabis misuse both separately and in combination. This work highlights the importance of including the assessment of alcohol misuse in addition to cannabis misuse in future treatment guidelines and research.

Synthetic cannabinoid use in psychiatric patients and relationship to hospitalisation: A retrospective electronic case register study

INTRODUCTION AND OBJECTIVES

Cannabis use has been associated with psychosis and with poor outcome in patients with mental illness. Synthetic cannabinoids (SCs) have been suggested to pose an even greater risk to mental health, but the effect on clinical outcome has not been directly measured. In this study, we aimed to investigate the demographics and hospitalisation of psychiatric patients who were SC users.

METHODS

We searched the Biomedical Research Centre Clinical Record Interactive Search register for SC users and age- and sex-matched SC non-users who had been psychiatric patients under the South London and Maudsley NHS Trust. We recorded diagnosis, homelessness, cannabis use and the total number of days admitted as an inpatient to secondary and tertiary mental-health services.

RESULTS

We identified 635 SC users and 635 age- and sex-matched SC non-users. SC users were significantly more likely to be homeless (χ²=138.0; p<0.0001) and to use cannabis (χ²=257.3; p<0.0001) than SC non-users. SC users had significantly more inpatient days after their first recorded use of SCs than controls (M (SD)=85.5 (199.7) vs. 25.4 (92.32); p<0.0001). Post hoc tests revealed that SC non-users who used cannabis had fewer inpatient days than SC users (p<0.0001), and that non-users of both SC and cannabis had fewer inpatient days than SC non-using cannabis users (p=0.02).

CONCLUSIONS

SC use may lead to an increase in the number of days spent in hospital in patients with psychiatric illness. This highlights the need for clinicians to ask specifically about SC use.

Contribution of CB2 receptors in schizophrenia-related symptoms in various animal models: Short review

Schizophrenia is a severe and chronic mental disease with a high prevalence and a variety of symptoms. Data from behavioural studies suggest that it is rational to investigate the endocannabinoid system (ECS) and its cannabinoid receptor (CBr) because they seem to underlie susceptibility to schizophrenia, and these findings have pointed to several lines of future research. Currently, most available studies address the role of CBr type 1 in schizophrenia-like responses. Here, we present for the first time, a review that demonstrates the pivotal role of CBr type 2 in the regulation of neurobiological processes underlying cognition, psychosis- and mood-related (anxiety, depression) behaviours, all of which may be included in schizophrenia symptoms. This review is based on available evidence from the PubMed database regarding schizophrenia-like symptoms induced via CB2r modulation in various animal models. The data presented in this manuscript indicate that CB2r could be a promising new key target in the treatment of different central nervous system (CNS) disorders, which manifest as psychosis, mood-related disturbances and/or memory impairment.

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.

Factor structure of the Cannabis Experiences Questionnaire in a first-episode psychosis sample

AIM

The Cannabis Experiences Questionnaire (CEQ) was developed to measure the subjective experiences of cannabis use both during and after intoxication. Despite the need to better understand the nature of the complex and significant relationship between cannabis use and early psychosis, this questionnaire has rarely been used in individuals with first-episode psychosis.

METHODS

We conducted a set of factor analyses using CEQ data from 194 first-episode psychosis patients who used cannabis in order to uncover the underlying factor structure of the questionnaire and thus the overarching types of psychological experiences during/after using cannabis in young people with psychotic disorders.

RESULTS

Our exploratory factor analysis identified 4 subscales, including: Distortions of Reality and Self-Perception (Factor 1), Euphoria Effects (Factor 2), Slowing and Amotivational Effects (Factor 3), and Anxiety and Paranoia Effects (Factor 4).

CONCLUSIONS

Elucidating the underlying factor structure of the CEQ in first-episode psychosis samples could help researchers move towards a deeper understanding of the types of experiences associated with cannabis intoxication among young adults with first-episode psychosis and could inform the development of programs designed to reduce use, improve the course of illness, and possibly delay or prevent the onset of psychotic symptoms in those at risk.

Impact of tobacco, alcohol and cannabis use on treatment outcomes among patients experiencing first episode psychosis: Data from the national RAISE-ETP study

AIM

The primary aim of this study was to examine the effect of recent tobacco, alcohol and cannabis use on treatment outcomes among participants experiencing first episode psychosis (FEP).

METHODS

Secondary data analyses were conducted on 404 participants enrolled in the Recovery After an Initial Schizophrenia Episode-Early Treatment Program (RAISE-ETP) study. RAISE-ETP investigated the effectiveness of a coordinated specialty care (CSC) intervention for FEP in community mental health agencies in the United States. Generalized estimating equations were used to examine whether recent tobacco smoking, alcohol, and cannabis use at baseline were associated with illness severity, number of antipsychotic pills missed, psychiatric symptoms and quality of life during the 24-month treatment period, after controlling for duration of untreated psychosis and treatment group.

RESULTS

At baseline, roughly 50% (n = 209) of participants reported recent tobacco, 28% (n = 113) alcohol and 24% (n = 95) cannabis use. Tobacco smokers had higher levels of illness severity (β = .24; P < .005), a higher number of missed pills (β = 2.89; P < .05), higher psychiatric symptoms and lower quality of life during treatment relative to non-smokers. Alcohol users had a higher number of missed pills (β = 3.16; P < .05) during treatment and cannabis users had higher levels of illness severity (β = .18; P < .05) and positive symptoms (β = 1.56; P < .05) relative to non-users.

CONCLUSIONS

Tobacco, alcohol and cannabis use are common in youth seeking treatment for FEP. Tobacco smoking was associated with more negative clinical outcomes. These findings have implications for including interventions targeting these areas of substance use within current CSC models.

Impact of comprehensive treatment for first episode psychosis on substance use outcomes: A randomized controlled trial

Lifetime co-occurring substance use disorders are common at the time of presentation for treatment of a first episode of primary psychosis and persistent substance use disorder (SUD) leads to poorer outcomes. We assessed whether the NAVIGATE program, a coordinated specialty care service that includes optional substance abuse content reduced substance use compared to usual care in 404 individuals in the Recovery After Initial Schizophrenia Episode-Early Treatment Program (RAISE-ETP) study. Participants were randomized to two years of NAVIGATE (n = 223) or usual care (n = 181) and assessed monthly for substance use. At baseline, over one-half (51.7%) of the participants met criteria for a lifetime SUD, including over one-third with alcohol use disorder (36.4%) and with cannabis use disorder (34.7%). Contrary to our hypothesis, there was no treatment group by time interaction effect on days of self-reported substance use over the two-year follow-up. Participant exposure to the substance abuse component of the NAVIGATE program was low, suggesting that modifications to the program and training method for clinicians may be needed. Further research is needed to determine the most effective strategies for addressing substance use disorders in persons recovering from a first episode of psychosis.

Impact of comorbid cannabis use on outcome in first episode psychosis

AIM

Comorbid cannabis abuse is common in patients with early psychosis. Little is known about the effect of stopping cannabis use on positive, negative and depressive symptoms. Few studies have controlled for multiple substance use that may mask the specific role that cannabis plays in symptom outcomes. The aim of this study was to investigate whether course and level of cannabis use negatively impacted early psychosis patient symptom profiles (positive, negative and depressive symptoms) over 24 months.

METHODS

One hundred and ninety-two patients admitted to an early psychosis intervention programme in a naturalistic setting were followed across three time periods: initial presentation, 12 and 24 months. Patients' clinical characteristics (substance use, positive/negative symptoms and depressive symptoms) were assessed at each time period.

RESULTS

There were no significant associations found between cannabis abuse and positive and negative symptoms. Continuation and discontinuation of cannabis use were not significant for cannabis or any other substance when compared to positive and negative symptoms. There was a significant interaction between cannabis and alcohol for depressive symptoms, where depressive symptoms were significantly higher in patients who abused cannabis without co-occurring alcohol abuse when compared to non-cannabis using patients.

CONCLUSION

The current study findings indicate a complex interaction between cannabis and alcohol use in a sample of early psychosis patients across 24 months. More research is needed into the association between ceasing cannabis use and long-term outcome for early psychosis patients. Of particular importance is the interaction between level of cannabis and alcohol use as it is related to symptom outcome in early psychosis patients.

Clinical characteristics of primary psychotic disorders with concurrent substance abuse and substance-induced psychotic disorders: A systematic review

BACKGROUND

Distinguishing between a primary psychotic disorder with concurrent substance abuse (PPD+SA) and a substance-induced psychotic disorder (SIPD) can be diagnostically challenging. We aimed to determine if these two diagnoses are clinically distinct, particularly in relation to psychopathology. In addition, we aimed to examine the specific clinical features of cannabis-induced psychotic disorder (CIPD) as compared to primary psychotic disorder with concurrent cannabis abuse (PPD+CA) and also to SIPD associated with any substance.

METHODS

A systematic review of SIPD literature using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Using strict inclusion criteria, a total of six studies examining SIPD were included in the review (two of which only considered psychosis induced by cannabis alone). The findings did not reveal many consistent differences in psychopathology. However, we did find that that compared to PPD+SA, individuals with SIPD have a weaker family history of psychotic disorder; a greater degree of insight; fewer positive symptoms and fewer negative symptoms; more depression (only in CIPD) and more anxiety.

CONCLUSION

There remains a striking paucity of information on the psychopathology, clinical characteristics and outcome of SIPD. Our review highlights the need for further research in this area.

The relationship between illicit amphetamine use and psychiatric symptom profiles in schizophrenia and affective psychoses

This study examines whether illicit amphetamine use is associated with differences in the prevalence of specific psychiatric symptoms in a community sample of individuals diagnosed with schizophrenia or affective psychotic disorders. Data was drawn from the Australian Survey of High Impact Psychosis. The Diagnostic Interview for Psychosis was used to measure substance use and psychiatric symptoms. Participants had used amphetamine within their lifetime and had an ICD-10 diagnosis of schizophrenia (n = 347) or an affective psychotic disorder (n = 289). The past year prevalence of psychiatric symptoms was compared among those who had used amphetamine in the past year (past-year use, 32%) with those who had not (former use, 68%). Univariate logistic regression analysis indicated that past-year users with schizophrenia had a significantly higher past year prevalence of hallucinations, persecutory delusions, racing thoughts, dysphoria, and anhedonia relative to former amphetamine users with schizophrenia. There were no significant differences in symptoms between past-year and former users with affective psychotic disorders. The relationship between amphetamine use and specific psychiatric symptoms varies across different psychotic disorders. Amphetamine use may hinder prognosis by exacerbating symptoms of schizophrenia through dopaminergic dysfunctions or depressive vulnerabilities, however, this needs to be confirmed by prospective longitudinal research.

Therapeutic potential of medicinal marijuana: an educational primer for health care professionals

With the proposed Canadian July 2018 legalization of marijuana through the Cannabis Act, a thorough critical analysis of the current trials on the efficacy of medicinal marijuana (MM) as a treatment option is necessary. This review is particularly important for primary care physicians whose patients may be interested in using MM as an alternative therapy. In response to increased interest in MM, Health Canada released a document in 2013 for general practitioners (GPs) as an educational tool on the efficacy of MM in treating some chronic and acute conditions. Although additional studies have filled in some of the gaps since the release of the Health Canada document, conflicting and inconclusive results continue to pose a challenge for physicians. This review aims to supplement the Health Canada document by providing physicians with a critical yet concise update on the recent advancements made regarding the efficacy of MM as a potential therapeutic option. An update to the literature of 2013 is important given the upcoming changes in legislation on the use of marijuana. Also, we briefly highlight the current recommendations provided by Canadian medical colleges on the parameters that need to be considered prior to authorizing MM use, routes of administration as well as a general overview of the endocannabinoid system as it pertains to cannabis. Lastly, we outline the appropriate medical conditions for which the authorization of MM may present as a practical alternative option in improving patient outcomes as well as individual considerations of which GPs should be mindful. The purpose of this paper is to offer physicians an educational tool that provides a necessary, evidence-based analysis of the therapeutic potential of MM and to ensure physicians are making decisions on the therapeutic use of MM in good faith.

Secular trends in the age at onset of bipolar I disorder - Support for birth cohort effects from interational, multi-centre clinical observational studies

OBJECTIVE

To examine any association of birth decade, sex and exposure to alcohol and/or substance use disorders (ASUD) with age at onset (AAO) of bipolar I disorder (BD-I).

METHODS

Using data from a representative clinical sample of 3896 BD-I cases recruited from 14 European countries, we examined AAO distributions in individuals born in consecutive birth decades. Cumulative probabilities with Mantel-Cox log-rank tests, pairwise comparisons and Odds Ratios (OR) with 95% confidence intervals (95% CI) were employed to analyze AAO according to birth decade, sex, and presence or absence of an ASUD.

RESULTS

In the total sample, median AAO of BD-I decreased from about 41 years for those born in the 1930s to about 26 years for those born in the 1960s. In a sub-sample of 1247 individuals (selected to minimize confounding), AAO significantly decreased for males and females born in each consecutive decade between 1930 and 50 (OR: 0.65; 95% CI: 0.51, 0.81), and for cases with an ASUD as compared to without (OR: 0.77, 95% CI: 0.69, 0.87). The best fitting regression model identified an independent effect for each birth decade and an interaction between ASUD status and sex, with a consistently earlier AAO in males with an ASUD (OR: 0.79: 95% CI: 0.70, 0.91).

CONCLUSIONS

In BD-I cases diagnosed according to internationally recognized criteria and recruited to pan-European clinical observational studies, the AAO distributions are compatible with a birth cohort effect. A potentially modifiable risk factor, namely ASUD status, was associated with the observed reduction in AAO, especially in males.

Effects of extended cannabis abstinence on clinical symptoms in cannabis dependent schizophrenia patients versus non-psychiatric controls

BACKGROUND

Rates of cannabis use among patients with schizophrenia are high, however little is understood about clinical effects of continued cannabis use and cessation after illness onset. Therefore, we investigated the effects of 28-days of cannabis abstinence on psychotic and depressive symptomatology in cannabis dependent patients with schizophrenia.

METHOD

Males with cannabis dependence and co-morbid schizophrenia (n=19) and non-psychiatric controls (n=20) underwent 28-days of monitored cannabis abstinence. Clinical symptoms were assessed at baseline and then weekly. Abstinence was encouraged using weekly therapy sessions and contingency reinforcement, confirmed by twice-weekly urine assays.

RESULTS

Forty-two percent (8/19) of patients and 55% (11/20) of controls achieved 28-days of sustained cannabis abstinence. In patients, PANSS subscores did not change over time irrespective of abstinence status. In contrast, patient abstainers demonstrated a more pronounced reduction in depression scores compared to non-abstainers, however, the Abstinence Status x Time interaction was non-significant.

DISCUSSION

Short-term (28-days) cannabis abstinence is not associated with improvement in psychotic symptoms, but may be associated with improvement in depressive symptomatology in patients with schizophrenia. Future studies employing larger samples as well as a continuous cannabis-using group may help to better characterize the causal effects of cannabis on symptom outcomes in this disorder.

A comprehensive approach to managing threats of violence on a university or college campus

Horrifying, high profile acts of violence on campuses remain relatively rare, nevertheless, academic administrators are required to manage threats of violence on campus on an increasingly regular basis. These threats take two primary forms, those in which the perpetrator and the intended victim(s) are clearly identified, often involving repeated threats and threatening behaviour towards an individual; and those involving anonymous threats to commit acts of larger scale violence. Complicating factors in managing these threats include: fear contagion; mass media and social media attention; responsibilities to all members of the university community sometimes including individuals issuing the threat and the intended victims; demands for safety and security measures that are often at odds with professional advice; and permeable campus boundaries that cause security challenges. This paper considers the changing landscape of threat assessment and risk assessment on university and college campuses and suggests opportunities for partnerships between forensic mental health professionals and academic administrators.

The Effect of Substance Use on 10-Year Outcome in First-Episode Psychosis

Substance use is common in first-episode psychosis (FEP) and has been linked to poorer outcomes with more severe psychopathology and higher relapse rates. Early substance discontinuation appears to improve symptoms and function. However, studies vary widely in their methodology, and few have examined patients longitudinally, making it difficult to draw conclusions for practice and treatment. We aimed to investigate the relationship between substance use and early abstinence and the long-term course of illness in a representative sample of FEP patients. Out of 301 included patients, 266 could be divided into 4 groups based on substance use patterns during the first 2 years of treatment: persistent users, episodic users, stop-users and nonusers. Differences in clinical and functional measures during the follow-up period were assessed using linear mixed effects models for the analysis of repeated measures data. Patients who stopped using substances within the first 2 years after diagnosis had outcomes similar to those who had never used with fewer symptoms than episodic or persistent users. Both episodic and persistent users had lower rates of symptom remission than nonusers, and persistent users also had more negative symptoms than those who stopped using. Our findings emerge from one of very few long-term longitudinal studies examining substance use cessation in FEP with 10-year follow-up. The results convey hope that the detrimental effects of substance abuse on mental health may be significantly reversed if one stops the abuse in time. This can help patients who struggle with addiction with their motivation to embrace abstinence.

Premorbid cannabis use is associated with more symptoms and poorer functioning in schizophrenia spectrum disorder

BACKGROUND

Cannabis use disorder is associated with an earlier age at onset and a more severe outcome of schizophrenia spectrum disorders. The role of cannabis use before the onset of illness (premorbid cannabis use) has not been fully investigated. We here examined how amount and type of premorbid cannabis use was associated with the later course of illness including current substance use, symptoms and level of functioning in schizophrenia spectrum disorder.

METHOD

We used a naturalistic sample of patients with DSM-IV schizophrenia spectrum disorders with a comprehensive history of illness and substance use. Data on premorbid substance use was obtained from comprehensive self-report. The relationship to outcome was investigated using regression models that included current substance use and premorbid functioning.

RESULTS

Pre-schizophrenia cannabis use was significantly associated with more severe psychotic symptoms and impaired functioning. Higher levels of premorbid cannabis use were associated with higher levels of current psychotic symptoms. These associations were independent of current substance use and premorbid functioning. Early use of cannabis (age <17 years) was associated with earlier age at onset of psychosis, independently of potential confounders.

CONCLUSIONS

Pre-psychosis cannabis use affects illness outcome in schizophrenia spectrum disorders, and is associated with lower age at onset of psychosis. These findings of independent negative effects of premorbid cannabis use in schizophrenia suggest that a limitation of the general use of cannabis may have beneficial health effects.

Differential effects of childhood trauma and cannabis use disorders in patients suffering from schizophrenia

BACKGROUND

Childhood trauma (CT) and cannabis use are both environmental and modifier risk factors for schizophrenia. However, little is known about how they interact in schizophrenia. We examined the main effect of each of these two environmental factors on the clinical expression of the disease using a large set of variables, and we tested whether and how cannabis and CT interact to influence the course and the presentation of the illness.

METHODS

A sample of 366 patients who met the DSM-IV-TR criteria for schizophrenia was recruited through the FACE-SCZ (Fondamental Advanced Centre of Expertise - Schizophrenia) network. Patients completed a large standardized clinical evaluation including Structured Clinical Interview for DSM Disorders-I (SCID-I), Positive and Negative Symptoms Scale (PANSS), Columbia-Suicide Severity Rating Scale (C-SSRS), Global Assessment of Functioning (GAF), Short-Quality of Life-18 (S-QoL-18), and Medication Adherence Rating Scale (MARS). We assessed CT with the Childhood Trauma Questionnaire and cannabis status with SCID-I.

RESULTS

CT significantly predicted the number of hospitalizations, GAF, and S-QoL-18 scores, as well as the PANSS total, positive, excitement, and emotional distress scores. Cannabis use disorders significantly predicted age of onset, and MARS. There was no significant interaction between CT and cannabis use disorders. However, we found evidence of a correlation between these two risk factors.

CONCLUSIONS

CT and cannabis both have differential deleterious effects on clinical and functional outcomes in patients with schizophrenia. Our results highlight the need to systematically assess the presence of these risk factors and adopt suitable therapeutic interventions.

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.

Cannabis Use Is Associated With Increased Psychotic Symptoms and Poorer Psychosocial Functioning in First-Episode Psychosis: A Report From the UK National EDEN Study

OBJECTIVE

The use of cannabis during the early stage of psychosis has been linked with increased psychotic symptoms. This study aimed to examine the use of cannabis in the 12 months following a first-episode of psychosis (FEP) and the link with symptomatic course and outcome over 1 year post psychosis onset.

DESIGN AND SETTING

One thousand twenty-seven FEP patients were recruited upon inception to specialized early intervention services (EIS) for psychosis in the United Kingdom. Participants completed assessments at baseline, 6 and 12 months.

RESULTS

The results indicate that the use of cannabis was significantly associated with increased severity of psychotic symptoms, mania, depression and poorer psychosocial functioning. Continued use of cannabis following the FEP was associated with poorer outcome at 1 year for Positive and Negative Syndrome Scale total score, negative psychotic symptoms, depression and psychosocial functioning, an effect not explained by age, gender, duration of untreated psychosis, age of psychosis onset, ethnicity or other substance use.

CONCLUSION

This is the largest cohort study of FEP patients receiving care within EIS. Cannabis use, particularly "continued use," was associated with poorer symptomatic and functional outcome during the FEP. The results highlight the need for effective and early intervention for cannabis use in FEP.

Association of cannabis use with hospital admission and antipsychotic treatment failure in first episode psychosis: an observational study

OBJECTIVE

To investigate whether cannabis use is associated with increased risk of relapse, as indexed by number of hospital admissions, and whether antipsychotic treatment failure, as indexed by number of unique antipsychotics prescribed, may mediate this effect in a large data set of patients with first episode psychosis (FEP).

DESIGN

Observational study with exploratory mediation analysis.

SETTING

Anonymised electronic mental health record data from the South London and Maudsley NHS Foundation Trust.

PARTICIPANTS

2026 people presenting to early intervention services with FEP.

EXPOSURE

Cannabis use at presentation, identified using natural language processing.

MAIN OUTCOME MEASURES

admission to psychiatric hospital and clozapine prescription up to 5 years following presentation.

MEDIATOR

Number of unique antipsychotics prescribed.

RESULTS

Cannabis use was present in 46.3% of the sample at first presentation and was particularly common in patients who were 16-25, male and single. It was associated with increased frequency of hospital admission (incidence rate ratio 1.50, 95% CI 1.25 to 1.80), increased likelihood of compulsory admission (OR 1.55, 1.16 to 2.08) and greater number of days spent in hospital (β coefficient 35.1 days, 12.1 to 58.1). The number of unique antipsychotics prescribed, mediated increased frequency of hospital admission (natural indirect effect 1.09, 95% CI 1.01 to 1.18; total effect 1.50, 1.21 to 1.87), increased likelihood of compulsory admission (natural indirect effect (NIE) 1.27, 1.03 to 1.58; total effect (TE) 1.76, 0.81 to 3.84) and greater number of days spent in hospital (NIE 17.9, 2.4 to 33.4; TE 34.8, 11.6 to 58.1).

CONCLUSIONS

Cannabis use in patients with FEP was associated with an increased likelihood of hospital admission. This was linked to the prescription of several different antipsychotic drugs, indicating clinical judgement of antipsychotic treatment failure. Together, this suggests that cannabis use might be associated with worse clinical outcomes in psychosis by contributing towards failure of antipsychotic treatment.

Cannabis use in first episode psychosis: Meta-analysis of prevalence, and the time course of initiation and continued use

OBJECTIVES

Cannabis use is prevalent among people with first episode psychosis and the epidemiology of its use in early psychosis is unclear. We performed a meta-analysis of observational studies to determine; (1) the interval between age at initiation of cannabis use and age at onset of first episode psychosis, (2) the prevalence of cannabis use at time of first episode psychosis, and (3) the odds of continuing cannabis following treatment for first episode psychosis.

DATA SOURCES

Search of electronic databases MEDLINE, EMBASE, PsycINFO, Web of Science and CINAHL for English-language papers using search terms (psychosis OR schizophrenia) AND (cannabis OR marijuana) IN (title OR keyword OR abstract), current to October 2014.

STUDY SELECTION

Studies were included if they reported on prevalence of current cannabis use in first episode psychosis cohorts. A total of 37 samples were included for meta-analysis.

DATA EXTRACTION

Rates of cannabis use in each sample were extracted to determine prevalence estimates. The age at initiation of regular cannabis and age at onset of psychosis were used to determine the length of cannabis use preceding psychosis. Prevalence estimates at first episode psychosis and various time points of follow-up following first episode psychosis were analysed to determine odds ratio of continuing cannabis use. Data synthesis was performed using random-effects meta-analyses.

RESULTS

The pooled estimate for the interval between initiation of regular cannabis use and age at onset of psychosis was 6.3 years (10 samples, standardised mean difference = 1.56, 95% confidence interval = [1.40, 1.72]). The estimated prevalence of cannabis use at first episode psychosis was 33.7% (35 samples, 95% confidence interval = [31%, 39%]). Odds of continued cannabis use between 6 months and 10 years following first episode psychosis was 0.56 (19 samples, 95% confidence interval = [0.40, 0.79]).

Continued versus discontinued cannabis use in patients with psychosis: a systematic review and meta-analysis

BACKGROUND

Although the link between cannabis use and development of psychosis is well established, less is known about the effect of continued versus discontinued cannabis use after the onset of psychosis. We aimed to summarise available evidence focusing on the relationship between continued and discontinued cannabis use after onset of psychosis and its relapse.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE for articles published in any language from the database inception date up until April 21, 2015 that included a sample of patients with a pre-existing psychotic disorder with a follow-up duration of at least 6 months. We used a combination of search terms for describing cannabis, the outcome of interest (relapse of psychosis), and the study population. We excluded studies if continued cannabis use or discontinued cannabis use could not be established. We compared relapse outcomes between those who continued (CC) or discontinued (DC) cannabis use or were non-users (NC). We used summary data (individual patient data were not sought out) to estimate Cohen's d, which was entered into random effects models (REM) to compare CC with NC, CC with DC, and DC with NC. Meta-regression and sensitivity analyses were used to address the issue of heterogeneity.

FINDINGS

Of 1903 citations identified, 24 studies (16 565 participants) met the inclusion criteria. Independent of the stage of illness, continued cannabis users had a greater increase in relapse of psychosis than did both non-users (dCC-NC=0·36, 95% CI 0·22-0·50, p<0·0001) and discontinued users (dCC-DC=0·28, 0·12-0·44, p=0·0005), as well as longer hospital admissions than non-users (dCC-NC=0·36, 0·13 to 0·58, p=0·02). By contrast, cannabis discontinuation was not associated with relapse (dDC-NC=0·02, -0·12 to 0·15; p=0·82). Meta-regression suggested greater effects of continued cannabis use than discontinued use on relapse (dCC-NC=0·36 vs dDC-NC=0·02, p=0·04), positive symptoms (dCC-NC=0·15 vs dDC-NC=-0·30, p=0·05) and level of functioning (dCC-NC=0·04 vs dDC-NC=-0·49, p=0·008) but not on negative symptoms (dCC-NC=-0·09 vs dDC-NC=-0·31, p=0·41).

INTERPRETATION

Continued cannabis use after onset of psychosis predicts adverse outcome, including higher relapse rates, longer hospital admissions, and more severe positive symptoms than for individuals who discontinue cannabis use and those who are non-users. These findings point to reductions in cannabis use as a crucial interventional target to improve outcome in patients with psychosis.

FUNDING

UK National Institute of Health Research.

Cannabis and Psychosis: a Critical Overview of the Relationship

Interest in the relationship between cannabis use and psychosis has increased dramatically in recent years, in part because of concerns related to the growing availability of cannabis and potential risks to health and human functioning. There now exists a plethora of scientific articles addressing this issue, but few provide a clear verdict about the causal nature of the cannabis-psychosis association. Here, we review recent research reports on cannabis and psychosis, giving particular attention to how each report provides evidence relating to two hypotheses: (1) cannabis as a contributing cause and (2) shared vulnerability. Two primary kinds of data are brought to bear on this issue: studies done with schizophrenic patients and studies of first-episode psychosis. Evidence reviewed here suggests that cannabis does not in itself cause a psychosis disorder. Rather, the evidence leads us to conclude that both early use and heavy use of cannabis are more likely in individuals with a vulnerability to psychosis. The role of early and heavy cannabis use as a prodromal sign merits further examination, along with a variety of other problem behaviors (e.g., early or heavy use of cigarettes or alcohol and poor school performance). Future research studies that focus exclusively on the cannabis-psychosis association will therefore be of little value in our quest to better understand psychosis and how and why it occurs.

Utility of Washington Early Recognition Center Self-Report Screening Questionnaires in the Assessment of Patients with Schizophrenia and Bipolar Disorder

Early identification and treatment are associated with improved outcomes in bipolar disorder (BPD) and schizophrenia (SCZ). Screening for the presence of these disorders usually involves time-intensive interviews that may not be practical in settings where mental health providers are limited. Thus, individuals at earlier stages of illness are often not identified. The Washington Early Recognition Center Affectivity and Psychosis (WERCAP) screen is a self-report questionnaire originally developed to identify clinical risk for developing bipolar or psychotic disorders. The goal of the current study was to investigate the utility of the WERCAP Screen and two complementary questionnaires, the WERC Stress Screen and the WERC Substance Screen, in identifying individuals with established SCZ or BPD. Participants consisted of 35 BPD and 34 SCZ patients, as well as 32 controls (CON), aged 18-30 years. Univariate analyses were used to test for score differences between groups. Logistic regression and receiver operating characteristic (ROC) curves were used to identify diagnostic predictors. Significant group differences were found for the psychosis section of the WERCAP (pWERCAP; p < 0.001), affective section of the WERCAP (aWERCAP; p = 0.001), and stress severity (p = 0.027). No significant group differences were found in the rates of substance use as measured by the WERC Substance Screen (p = 0.267). Only the aWERCAP and pWERCAP scores were useful predictors of diagnostic category. ROC curve analysis showed the optimal cut point on the aWERCAP to identify BPD among our participant groups was a score of >20 [area under the curve (AUC): 0.87; sensitivity: 0.91; specificity: 0.71], while that for the pWERCAP to identify SCZ was a score of >13 (AUC: 0.89; sensitivity: 0.88; specificity: 0.82). These results indicate that the WERCAP Screen may be useful in screening individuals for BPD and SCZ and that identifying stress and substance-use severity can be rapidly done using self-report questionnaires. Larger studies in undiagnosed individuals will be needed to test the WERCAP Screen's ability to identify mania or psychosis in the community.

Temporal trends of alcohol and drug use among Inuit of Northern Quebec, Canada

BACKGROUND

Alcohol and drug use is a serious health problem for many indigenous populations across Canada, including Inuit. The literature on substance use in these populations is too sparse to devise public health interventions.

OBJECTIVE

The present article portrays alcohol and drug use among Inuit living in Nunavik (Northern Quebec) between the 1990s and 2000s, and identifies socio-demographic characteristics related to substance use.

DESIGN

The Santé Québec Health Survey (1992) and the Nunavik Inuit Health Survey Qanuippitaa (2004) served as databases for this empirical work. Statistical comparisons were made of substance use variables in the 2 samples. Proportions were compared by chi-square tests (p≤0.05) with benchmarking of statistics for all of Quebec and, when available, all of Canada.

RESULTS

Alcohol and drug use among Inuit increased significantly between 1992 and 2004, particularly among young adults. Alcohol users consumed significantly more alcohol per drinking episode than other Canadians in both time periods. Considerable cannabis use was widespread. In 2004, no significant differences in frequencies of heavy drinking episodes were observed by gender, with 60% of drug users consuming alcohol on a regular basis.

CONCLUSIONS

As in other populations from North America, this study profiles the increase in substance use among Inuit from Nunavik in the first part of the last 20 years. We observed distinct substance use patterns among them in comparison to other Canadians. Such findings, if replicated in the coming years, emphasize the need for major, culturally-relevant public health interventions in this population.

Cannabinoids and Schizophrenia: Risks and Therapeutic Potential

A convergence of evidence shows that use of Cannabis sativa is associated with increased risk of developing psychotic disorders, including schizophrenia, and earlier age at which psychotic symptoms first manifest. Cannabis exposure during adolescence is most strongly associated with the onset of psychosis amongst those who are particularly vulnerable, such as those who have been exposed to child abuse and those with family histories of schizophrenia. Schizophrenia that develops after cannabis use may have a unique clinical phenotype, and several genetic polymorphisms may modulate the relationship between cannabis use and psychosis. The endocannabinoid system has been implicated in psychosis both related and unrelated to cannabis exposure, and studying this system holds potential to increase understanding of the pathophysiology of schizophrenia. Anandamide signaling in the central nervous system may be particularly important. Δ(9)-Tetrahydrocannabinol in cannabis can cause symptoms of schizophrenia when acutely administered, and cannabidiol (CBD), another compound in cannabis, can counter many of these effects. CBD may have therapeutic potential for the treatment of psychosis following cannabis use, as well as schizophrenia, possibly with better tolerability than current antipsychotic treatments. CBD may also have anti-inflammatory and neuroprotective properties. Establishing the role of CBD and other CBD-based compounds in treating psychotic disorders will require further human research.

Relationship between cannabis and psychosis: Reasons for use and associated clinical variables

The mechanism underneath the relationship between cannabis and psychosis remains controversial, for which several hypotheses have been proposed, including cannabis as self-medication and cannabis as a risk for the development of psychosis. The aim of this work was to study the relationship between cannabis and psychosis in first-episode psychosis cannabis users and non-users, and non-psychotic cannabis users. The age at the first psychotic episode, duration of untreated psychosis, psychopathology and reasons for cannabis use were assessed. First-episode psychosis cannabis users showed an earlier age at psychosis onset than non-user patients. No significant differences in symptomatology were found. The distinguishing reasons to use cannabis for patients with first-episode psychosis with respect to non-psychotic users were to arrange their thoughts and deal with hallucinations and suspiciousness. These findings are in agreement with both hypotheses: self-medication and secondary psychosis hypothesis. However, longitudinal prospective cohort studies assessing reasons for cannabis use are needed to investigate both hypotheses and their complementarity.

Cannabinoids: is there a potential treatment role in epilepsy?

Cannabinoids have been used medicinally for centuries, and in the last decade, attention has focused on their broad therapeutic potential particularly in seizure management. While some cannabinoids have demonstrated anticonvulsant activity in experimental studies, their efficacy for managing clinical seizures has not been fully established. This commentary will touch on our understanding of the brain endocannabinoid system's regulation of synaptic transmission in both physiological and pathophysiological conditions, and review the findings from both experimental and clinical studies on the effectiveness of cannabinoids to suppress epileptic seizures. At present, there is preliminary evidence that non-psychoactive cannabinoids may be useful as anticonvulsants, but additional clinical trials are needed to fully evaluate the efficacy and safety of these compounds for the treatment of epilepsy.

The Epidemiology and Associated Phenomenology of Formal Thought Disorder: A Systematic Review

BACKGROUND

Authors of the Diagnostic and Statistical Manual, Fifth Edition (DSM-V) have recommended to "integrate dimensions into clinical practice." The epidemiology and associated phenomenology of formal thought disorder (FTD) have been described but not reviewed. We aimed to carry out a systematic review of FTD to this end.

METHODS

A systematic review of FTD literature, from 1978 to 2013, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 881 abstracts were reviewed and 120 articles met inclusion criteria; articles describing FTD factor structure (n = 15), prevalence and longitudinal course (n = 41), role in diagnosis (n = 22), associated clinical variables (n = 56), and influence on outcome (n = 35) were included. Prevalence estimates for FTD in psychosis range from 5% to 91%. Dividing FTD into domains, by factor analysis, can accurately identify 91% of psychotic diagnoses. FTD is associated with increased clinical severity. Poorer outcomes are predicted by negative thought disorder, more so than the typical construct of "disorganized speech."

CONCLUSION

FTD is a common symptom of psychosis and may be considered a marker of illness severity. Detailed dimensional assessment of FTD can clarify diagnosis and may help predict prognosis.

Birth weight and obstetric complications determine age at onset in first episode of psychosis

BACKGROUND

Earlier age at onset of psychosis (AOP) has been associated with poor social adjustment and clinical outcome. Genetic and environmental factors such as obstetric complications, parental history of psychosis, advanced paternal age at time of birth, low birth weight and gestational age, and use of drugs have been described as bringing AOP forward. This study aims to evaluate the relationship between AOP and these factors in a sample of first episode of psychosis (FEP) patients.

METHODS

Clinical and sociodemographic data, age at FEP, age of parents at birth, parental history of psychosis, drug-use habits of the mother during pregnancy and of the patient before psychotic onset, and Lewis and Murray obstetric complication scale were obtained from 90 patients with FEP. Statistical analysis was performed by means of Pearson correlations, Chi-square tests, Student T-test analyses and a linear regression model using SPSS version 22.

RESULTS

Pre-eclampsia, need for incubator at birth, use of forceps, parental history of psychosis, and low birth weight were associated with an earlier AOP. Use of forceps and birth weight are the variables which best predict AOP in FEP. Stimulant drugs, which were mostly used together with cannabis and cocaine, were the only substances associated with an earlier AOP.

CONCLUSIONS

Our findings are consistent with previous study results and underline the role of the prenatal period in the development of psychosis and the importance of careful monitoring of pregnancy and delivery, especially in cases with familial history.

Subclinical depressive symptoms and continued cannabis use: predictors of negative outcomes in first episode psychosis

Background

Although depressive symptoms in first episode psychosis have been associated with cannabis abuse, their influence on the long-term functional course of FEP patients who abuse cannabis is unknown. The aims of the study were to examine the influence of subclinical depressive symptoms on the long-term outcome in first episode-psychosis patients who were cannabis users and to assess the influence of these subclinical depressive symptoms on the ability to quit cannabis use.

Methods

64 FEP patients who were cannabis users at baseline were followed-up for 5 years. Two groups were defined: (a) patients with subclinical depressive symptoms at least once during follow-up (DPG), and (b) patients without subclinical depressive symptoms during follow-up (NDPG). Psychotic symptoms were measured using the Positive and Negative Syndrome Scale (PANSS), depressive symptoms using the Hamilton Depression Rating Scale (HDRS)-17, and psychosocial functioning was assessed using the Global Assessment of Functioning (GAF). A linear mixed-effects model was used to analyze the combined influence of cannabis use and subclinical depressive symptomatology on the clinical outcome.

Results

Subclinical depressive symptoms were associated with continued abuse of cannabis during follow-up (β= 4.45; 95% confidence interval [CI]: 1.78 to 11.17; P = .001) and with worse functioning (β = -5.50; 95% CI: -9.02 to -0.33; P = .009).

Conclusions

Subclinical depressive symptoms and continued cannabis abuse during follow-up could be predictors of negative outcomes in FEP patients.

The impact of cannabis use on clinical outcomes in recent onset psychosis

BACKGROUND

There are inconsistencies in findings as to whether cannabis use has a negative impact on clinical outcomes for people with established psychosis. Effects may be more evident on patients with recent onset psychosis.

AIM

To investigate the relationship between cannabis use and clinical outcome, including whether change in cannabis use affects psychotic symptoms, affective symptoms, functioning and psychotic relapse in a sample of people in early psychosis with comorbid cannabis abuse or dependence.

METHODS

One hundred and ten participants were examined prospectively with repeated measures of substance use antecedent to psychopathology at baseline, 4.5, 9, and 18 months. We used random intercept models to estimate the effects of cannabis dose on subsequent clinical outcomes and whether change in cannabis use was associated with change in outcomes.

RESULTS

There was no evidence of a specific association between cannabis use and positive symptoms, or negative symptoms, relapse or hospital admissions. However, a greater dose of cannabis was associated with subsequent higher depression and anxiety. Change in the amount of cannabis used was associated with statistically significant corresponding change in anxiety scores, but not depression. Additionally, reductions in cannabis exposure were related to improved patient functioning.

CONCLUSIONS

Reducing cannabis may be directly associated with improvements in anxiety and functioning, but not other specific symptoms.

Drug models of schizophrenia

Schizophrenia is a complex mental health disorder with positive, negative and cognitive symptom domains. Approximately one third of patients are resistant to currently available medication. New therapeutic targets and a better understanding of the basic biological processes that drive pathogenesis are needed in order to develop therapies that will improve quality of life for these patients. Several drugs that act on neurotransmitter systems in the brain have been suggested to model aspects of schizophrenia in animals and in man. In this paper, we selectively review findings from dopaminergic, glutamatergic, serotonergic, cannabinoid, GABA, cholinergic and kappa opioid pharmacological drug models to evaluate their similarity to schizophrenia. Understanding the interactions between these different neurotransmitter systems and their relationship with symptoms will be an important step towards building a coherent hypothesis for the pathogenesis of schizophrenia.

Cannabis use and transition to psychosis in people at ultra-high risk

BACKGROUND

Cannabis use is associated with an increased risk of developing a psychotic disorder but the temporal relationship between cannabis use and onset of illness is unclear. The objective of this study was to assess prospectively the influence of cannabis use on transition to psychosis in people at ultra-high risk (UHR) for the disorder.

METHOD

Lifetime and continued cannabis use was assessed in a consecutively ascertained sample of 182 people (104 male, 78 female) at UHR for psychosis. Individuals were then followed clinically for 2 years to determine their clinical outcomes.

RESULTS

Lifetime cannabis use was reported by 134 individuals (73.6%). However, most of these individuals had stopped using cannabis before clinical presentation (n=98, 73.1%), usually because of adverse effects. Among lifetime users, frequent use, early-onset use and continued use after presentation were all associated with an increase in transition to psychosis. Transition to psychosis was highest among those who started using cannabis before the age of 15 years and went on to use frequently (frequent early-onset use: 25%; infrequent or late-onset use: 5%; χ(2)1=10.971, p=0.001). However, within the whole sample, cannabis users were no more likely to develop psychosis than those who had never used cannabis (cannabis use: 12.7%; no use: 18.8%; χ(2)1=1.061, p=0.303).

CONCLUSIONS

In people at UHR for psychosis, lifetime cannabis use was common but not related to outcome. Among cannabis users, frequent use, early-onset use and continued use after clinical presentation were associated with transition to psychosis.

Cannabis use and first manic episode

BACKGROUND

Cannabis is the most commonly abused drug among patients with bipolar disorder. Available data has shown that the risk of psychotic disorders increases with the frequency and intensity of cannabis abuse. The present purpose was to review relevant studies to investigate whether cannabis use can be linked to the onset of mania in bipolar disorder.

METHODS

Articles published between 1972 and December 2013 were searched on Medline and PsychInfo using the following keywords: first manic episode, or onset mania, or bipolar disorder and cannabis. Relevant papers cited in the references of selected articles were further considered for inclusion into the review.

RESULTS

Lifetime use of cannabis among bipolar patients appears to be around 70% and approximately 30% of patients with a bipolar disorder present a comorbidity of cannabis abuse or dependence. Cannabis use is associated with younger age at onset of first mania and with more frequent depressive or manic episodes, although the evidence is somewhat inconsistent. Likewise cannabis consumption is related to poorer outcome and an increased risk of rapid cycling or mixed episodes. In contrast, neuro-cognitive functioning seems to be positively affected in patients with psychiatric comorbidity. While cannabis use often precedes first manic episodes, the causal direction remains to be determined.

LIMITATIONS

Variations in definition of cannabis use/dependence. Lack of controlled studies limiting definite conclusions about a putative causal relationship between cannabis and onset of mania.

CONCLUSIONS

Further investigations are needed to clarify the relationships between cannabis use and first manic episode.