Cannabis use and outcome of recent onset psychosis

Using Task-fMRI to Explore the Relationship Between Lifetime Cannabis Use and Cognitive Control in Individuals With First-Episode Schizophrenia

While continued cannabis use and misuse in individuals with schizophrenia is associated with a variety of negative outcomes, individuals with a history of use tend to show higher cognitive performance compared to non-users. While this is replicated in the literature, few studies have used task-based functional magnetic resonance imaging (fMRI) to evaluate whether the brain networks underpinning these cognitive features are similarly impacted. Forty-eight first-episode individuals with schizophrenia (FES) with a history of cannabis use (FES + CAN), 28 FES individuals with no history of cannabis use (FES-CAN), and 59 controls (CON) performed the AX-Continuous Performance Task during fMRI. FES+CAN showed higher cognitive control performance (d'-context) compared to FES-CAN (P < .05, ηp 2 = 0.053), and both FES+CAN (P < .05, ηp 2 = 0.049) and FES-CAN (P < .001, ηp 2 = 0.216) showed lower performance compared to CON. FES+CAN (P < .05, ηp 2 = 0.055) and CON (P < 0.05, ηp 2 = 0.058) showed higher dorsolateral prefrontal cortex (DLPFC) activation during the task compared to FES-CAN, while FES+CAN and CON were not significantly different. Within the FES+CAN group, the younger age of initiation of cannabis use was associated with lower IQ and lower global functioning. More frequent use was also associated with higher reality distortion symptoms at the time of the scan. These data are consistent with previous literature suggesting that individuals with schizophrenia and a history of cannabis use have higher cognitive control performance. For the first time, we also reveal that FES+CAN have higher DLPFC brain activity during cognitive control compared to FES-CAN. Several possible explanations for these findings are discussed.

Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals

Background

The association between cannabis use and positive symptoms in schizophrenia spectrum disorders is well documented, especially via meta-analyses. Yet, findings are inconsistent regarding negative symptoms, while other dimensions such as disorganization, depression, and excitement, have not been investigated. In addition, meta-analyses use aggregated data discarding important confounding variables which is a source of bias.

Methods

PubMed, ScienceDirect and PsycINFO were used to search for publications from inception to September 27, 2022. We contacted the authors of relevant studies to extract raw datasets and perform an Individual Participant Data meta-analysis (IPDMA). Inclusion criteria were: psychopathology of individuals with schizophrenia spectrum disorders assessed by the Positive and Negative Syndrome Scale (PANSS); cannabis-users had to either have a diagnosis of cannabis use disorder or use cannabis at least twice a week. The main outcomes were the PANSS subscores extracted via the 3-factor (positive, negative and general) and 5-factor (positive, negative, disorganization, depression, excitement) structures. Preregistration is accessible via Prospero: ID CRD42022329172.

Findings

Among the 1149 identified studies, 65 were eligible and 21 datasets were shared, totaling 3677 IPD and 3053 complete cases. The adjusted multivariate analysis revealed that relative to non-use, cannabis use was associated with higher severity of positive dimension (3-factor: Adjusted Mean Difference, aMD = 0.34, 95% Confidence Interval, CI = [0.03; 0.66]; 5-factor: aMD = 0.38, 95% CI = [0.08; 0.63]), lower severity of negative dimension (3-factor: aMD = -0.49, 95% CI [-0.90; -0.09]; 5-factor: aMD = -0.50, 95% CI = [-0.91; -0.08]), higher severity of excitement dimension (aMD = 0.16, 95% CI = [0.03; 0.28]). No association was found between cannabis use and disorganization (aMD = -0.13, 95% CI = [-0.42; 0.17]) or depression (aMD = -0.14, 95% CI = [-0.34; 0.06]).

Interpretation

No causal relationship can be inferred from the current results. The findings could be in favor of both a detrimental and beneficial effect of cannabis on positive and negative symptoms, respectively. Longitudinal designs are needed to understand the role of cannabis is this association. The reported effect sizes are small and CIs are wide, the interpretation of findings should be taken with caution.

Funding

This research did not receive any specific grant or funding. Primary financial support for authors was provided by Le Vinatier Psychiatric Hospital.

Challenges and considerations for treating PTSD with medicinal cannabis: the Australian clinician's perspective

INTRODUCTION

Preclinical and experimental research have provided promising evidence that medicinal cannabis may be efficacious in the treatment of posttraumatic stress disorder (PTSD). However, implementation of medicinal cannabis into routine clinical therapies may not be straightforward.

AREAS COVERED

In this review, we describe some of the clinical, practical, and safety challenges that must be addressed for cannabis-based treatment of PTSD to be feasible in a real-world setting. These issues are especially prevalent if medicinal cannabis is to be combined with trauma-focused psychotherapy.

EXPERT OPINION

Future consideration of the clinical and practical considerations of cannabis use in PTSD therapy will be essential to both the efficacy and safety of the treatment protocols that are being developed. These issues include dose timing and titration, potential for addiction, product formulation, windows of intervention, and route of administration. In particular, exposure therapy for PTSD involves recall of intense emotions, and the interaction between cannabis use and reliving of trauma memories must be explored in terms of patient safety and impact on therapeutic outcomes.

The Relationship Between Cannabis, Cognition, and Schizophrenia: It's Complicated

The consequences of cannabis use, especially in the context of schizophrenia, have gained increased importance with the legalization of cannabis in North America and across the globe. Cannabis use has multifaceted impacts on cognition in schizophrenia patients and healthy subjects. Healthy subjects, particularly those who initiated cannabis use at earlier ages and used high-potency cannabis for longer durations, exhibited poorer cognition mainly in working memory and attention. Cannabis use in schizophrenia has been associated with symptom exacerbation, longer and more frequent psychotic episodes, and poorer treatment outcomes. However, cannabis-using patients have better overall cognitive performance compared to patients who were not cannabis users. Interestingly, these effects were only apparent in lifetime cannabis users, but not in current (or within last 6 months) users. Moreover, higher frequency and earlier age of cannabis use initiation (i.e., before 17 years of age) were associated with better cognitive performance, although they had an earlier illness onset. Three possible hypotheses seem to come forward to explain this paradox. First, some components of cannabis may have antipsychotic or cognitive-enhancing properties. Secondly, chronic cannabis use may alter endocannabinoid signaling in the brain which could be a protective factor for developing psychosis or cognitive impairments. A third explanation could be their representation of a phenotypically distinct patient group with more intact cognitive functioning and less neurodevelopmental pathology. Multiple factors need to be considered to understand the complex relationship between cannabis, cognitive function, and schizophrenia. In short, age at initiation, duration and rate of cannabis use, abstinence duration, co-use of substances and alcohol, prescribed medications, relative cannabinoid composition and potency of cannabis, presence of genetic and environmental vulnerability factors are prominent contributors to the variability in outcomes. Animal studies support the disruptive effects of Δ9-tetrahydrocannabinol (THC) administration during adolescence on attention and memory performance. They provide insights about interaction of cannabinoid receptors with other neurotransmitter systems, such as GABA and glutamate, and other regulatory molecules, such as PSD95 and synaptophysin. Cannabidiol (CBD), on the other hand, can improve cognitive deficits seen in neurodevelopmental and chemically-induced animal models of schizophrenia. Future studies focusing on bridging the translational gaps between human and animal studies, through the use of translationally relevant methods of exposure (e.g., vaping), consistent behavioral assessments, and congruent circuit interrogations (e.g., imaging) will help to further clarify this complex picture.

Epigenomic and Other Evidence for Cannabis-Induced Aging Contextualized in a Synthetic Epidemiologic Overview of Cannabinoid-Related Teratogenesis and Cannabinoid-Related Carcinogenesis

BACKGROUND

Twelve separate streams of empirical data make a strong case for cannabis-induced accelerated aging including hormonal, mitochondriopathic, cardiovascular, hepatotoxic, immunological, genotoxic, epigenotoxic, disruption of chromosomal physiology, congenital anomalies, cancers including inheritable tumorigenesis, telomerase inhibition and elevated mortality.

METHODS

Results from a recently published longitudinal epigenomic screen were analyzed with regard to the results of recent large epidemiological studies of the causal impacts of cannabis. We also integrate theoretical syntheses with prior studies into these combined epigenomic and epidemiological results.

RESULTS

Cannabis dependence not only recapitulates many of the key features of aging, but is characterized by both age-defining and age-generating illnesses including immunomodulation, hepatic inflammation, many psychiatric syndromes with a neuroinflammatory basis, genotoxicity and epigenotoxicity. DNA breaks, chromosomal breakage-fusion-bridge morphologies and likely cycles, and altered intergenerational DNA methylation and disruption of both the histone and tubulin codes in the context of increased clinical congenital anomalies, cancers and heritable tumors imply widespread disruption of the genome and epigenome. Modern epigenomic clocks indicate that, in cannabis-dependent patients, cannabis advances cellular DNA methylation age by 25-30% at age 30 years. Data have implications not only for somatic but also stem cell and germ line tissues including post-fertilization zygotes. This effect is likely increases with the square of chronological age.

CONCLUSION

Recent epigenomic studies of cannabis exposure provide many explanations for the broad spectrum of cannabis-related teratogenicity and carcinogenicity and appear to account for many epidemiologically observed findings. Further research is indicated on the role of cannabinoids in the aging process both developmentally and longitudinally, from stem cell to germ cell to blastocystoids to embryoid bodies and beyond.

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.

Cannabis use during the early COVID-19 pandemic: Use patterns, predictors, and subjective experiences

BACKGROUND

Even in the early stages, global crises such as the COVID-19 pandemic lead to serious dislocations of social life, secondary adjustment reactions to external restrictions and individual concerns. Coping mechanisms may also include dysfunctional strategies like an increase of drug use. Considering the wide-spread use of cannabis, the aim of this study was to elucidate the interplay of social restrictions, psychopathology, concerns related to the pandemic in addition to the users' experiences, motivations and consumption quantities during the early COVID-19 pandemic. It was presumed that cannabis intake would increase during the early phase of the crisis and that consumption quantities would be related to corona-related restrictions, concerns as well as subjective substance effects and psychopathology.

MATERIALS AND METHODS

As part of an international, cross-sectional, internet-based survey (N = 5,049) available in five languages, consumption quantities and patterns of cannabis use in the early phase of the pandemic from April to August 2020 were examined. Participants retrospectively rated restrictions and concerns related to the pandemic, motives of cannabis use prior to and during 1 month the pandemic, and subjective consumption effects.

RESULTS

Cannabis use behavior showed no significant differences when consumption quantities prior and during 1 month after the COVID-19 outbreak were compared. Higher quantities of cannabis intake prior and during 1 month of the pandemic as well as more corona-related concern were associated with an increased perception of positive effects of cannabis during the pandemic. Predictors of its use during 1 month of pandemic were higher pre-pandemic consumption quantity, older age, quarantinization, a lesser degree of being affected by negative effects of the pandemic and a stronger subjective experience of corona-related positive effects of cannabis. Comparisons of the motives for cannabis intake in the pre-pandemic versus the pandemic period showed that all rationales for consumption were reported less frequently, except boredom.

CONCLUSION

Frequencies of cannabis intake remained relatively stable in the early pandemic phase. Risk factors for increased use seem related to habitual consumption patterns that become more prominent under quarantinization. The use of cannabis as a dysfunctional coping strategy might not be amenable via self-report and should therefore receive special attention in clinical contexts.

ReMind, a smartphone application for psychotic relapse prediction: A longitudinal study protocol

BACKGROUND

Psychotic disorders are associated with a high rate of relapse. In addition to medication non-adherence, some psychosocial factors have been found to be predictive of relapse (e.g., poor premorbid adjustment, high expressed emotion and substance misuse). Impairments in cognitive functions including general memory functioning, set shifting, attention, processing speed and working memory have also been indicative of a subsequent psychotic episode. As clinical appointments do not always allow for timely or accurate detection of these early warning signs, the ReMind app is developed to explore potential relapse predictors and enhance the process of relapse monitoring.

AIM

The ReMind app aims (1) to assess whether verbal or visual working memory predicts psychotic relapse in 1 year and (2) to determine whether social factors such as stressful life events, level of expressed emotion and medication adherence also predict relapse in 1 year.

METHODS

This is a one-year prospective follow-up study involving 176 remitted patients diagnosed with schizophrenia or non-affective psychoses. Monthly relapse predictor assessments will be conducted via ReMind throughout the one-year study duration. These assessments include neurocognitive tasks and psychosocial questionnaires.

RESULTS

Recruitment began in August 2017 and is still ongoing. Preliminary user feedback suggested an overall positive experience with the app.

CONCLUSION

The ReMind app presents a step forward to the identification and sensitive detection of reliable psychosis relapse predictors. With its anticipated success, it may offer an alternative means of monitoring relapse for the Chinese-speaking population in the future.

Cannabis use and clinical outcome in people with first-episode schizophrenia spectrum disorders over 24 months of treatment

Cannabis use is associated with an unfavourable course of illness in schizophrenia, although several factors may confound this association. In this longitudinal study, we explored the influence of cannabis use on baseline symptom severity and treatment outcomes in 98 patients with first-episode schizophrenia spectrum disorders treated with a long acting injectable antipsychotic over 24 months. Using mixed models for repeated measures, we compared visit-wise changes in psychopathology, social and occupational functioning and quality of life between recent/current cannabis users (n=45) and non-users (n=53). There were no significant group by time interactions for any of our outcomes, and with the exception of poorer functionality in cannabis users at baseline, no significant differences in these domains at baseline or month 24. Also, remission rates were similar. However, more cannabis users met our operationally defined relapse criteria compared to non-users, and more frequent cannabis use over the course of treatment, as assessed by positive urine toxicology testing, predicted relapse. Our results suggest that cannabis users do not have poorer treatment response than non-users in terms of symptom reduction over the 24 months of treatment. However, dose-related risk of relapse remains with ongoing cannabis use, possibly by directly reducing the threshold for psychotic breakthrough.

What makes the psychosis 'clinical high risk' state risky: psychosis itself or the co-presence of a non-psychotic disorder?

AIMS

Although attenuated psychotic symptoms in the psychosis clinical high-risk state (CHR-P) almost always occur in the context of a non-psychotic disorder (NPD), NPD is considered an undesired 'comorbidity' epiphenomenon rather than an integral part of CHR-P itself. Prospective work, however, indicates that much more of the clinical psychosis incidence is attributable to prior mood and drug use disorders than to psychosis clinical high-risk states per se. In order to examine this conundrum, we analysed to what degree the 'risk' in CHR-P is indexed by co-present NPD rather than attenuated psychosis per se.

METHODS

We examined the incidence of early psychotic experiences (PE) with and without NPD (mood disorders, anxiety disorders, alcohol/drug use disorders), in a prospective general population cohort (n = 6123 at risk of incident PE at baseline). Four interview waves were conducted between 2007 and 2018 (NEMESIS-2). The incidence of PE, alone (PE-only) or with NPD (PE + NPD) was calculated, as were differential associations with schizophrenia polygenic risk score (PRS-Sz), environmental, demographical, clinical and cognitive factors.

RESULTS

The incidence of PE + NPD (0.37%) was lower than the incidence of PE-only (1.04%), representing around a third of the total yearly incidence of PE. Incident PE + NPD was, in comparison with PE-only, differentially characterised by poor functioning, environmental risks, PRS-Sz, positive family history, prescription of antipsychotic medication and (mental) health service use.

CONCLUSIONS

The risk in 'clinical high risk' states is mediated not by attenuated psychosis per se but specifically the combination of attenuated psychosis and NPD. CHR-P/APS research should be reconceptualised from a focus on attenuated psychotic symptoms with exclusion of non-psychotic DSM-disorders, as the 'pure' representation of a supposedly homotypic psychosis risk state, towards a focus on poor-outcome NPDs, characterised by a degree of psychosis admixture, on the pathway to psychotic disorder outcomes.

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.

Daily use of high-potency cannabis is associated with more positive symptoms in first-episode psychosis patients: the EU-GEI case-control study

BACKGROUND

Daily use of high-potency cannabis has been reported to carry a high risk for developing a psychotic disorder. However, the evidence is mixed on whether any pattern of cannabis use is associated with a particular symptomatology in first-episode psychosis (FEP) patients.

METHOD

We analysed data from 901 FEP patients and 1235 controls recruited across six countries, as part of the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) study. We used item response modelling to estimate two bifactor models, which included general and specific dimensions of psychotic symptoms in patients and psychotic experiences in controls. The associations between these dimensions and cannabis use were evaluated using linear mixed-effects models analyses.

RESULTS

In patients, there was a linear relationship between the positive symptom dimension and the extent of lifetime exposure to cannabis, with daily users of high-potency cannabis having the highest score (B = 0.35; 95% CI 0.14-0.56). Moreover, negative symptoms were more common among patients who never used cannabis compared with those with any pattern of use (B = -0.22; 95% CI -0.37 to -0.07). In controls, psychotic experiences were associated with current use of cannabis but not with the extent of lifetime use. Neither patients nor controls presented differences in depressive dimension related to cannabis use.

CONCLUSIONS

Our findings provide the first large-scale evidence that FEP patients with a history of daily use of high-potency cannabis present with more positive and less negative symptoms, compared with those who never used cannabis or used low-potency types.

Serotonin 2A receptors and cannabinoids

Accumulating evidence has proven that both exogenous cannabinoids as well as imbalances in the endocannabinoid system are involved in the onset and development of mental disorders such as anxiety, depression, or schizophrenia. Extensive recent research in this topic has mainly focused on the molecular mechanisms by which cannabinoid agonists may contribute to the pathophysiology of these disorders. Initially, serotonin neurotransmitter garnered most attention due to its relationship to mood disorders and mental diseases, with little attention to specific receptors. To date, the focus has redirected toward the understanding of different serotonin receptors, through a demonstration of its versatile pharmacology and synergy with different modulators. Serotonin 2A receptors are a good example of this phenomenon, and the complex signaling that they trigger appears of high relevance in the context of mental disorders, especially in schizophrenia. This chapter will analyze most relevant attributes of serotonin 2A receptors and the endocannabinoid system, and will highlight the evidence toward the functional bidirectional interaction between these elements in the brain as well as the impact of the endocannabinoid system dysregulation on serotonin 2A receptors functionality.

Problematic Drug Use Among Outpatients With Schizophrenia and Related Psychoses

Background: Problematic drug use is common among psychiatric patients and is linked with poorer course and outcomes of illness. The aim of this study is to assess the prevalence of problematic drug use, and to explore its sociodemographic correlates and associations with health behaviors and outcomes among outpatients with schizophrenia and related psychoses in Singapore. Methods: Data from 397 individuals who were aged 21-65 years and were seeking treatment for schizophrenia and related psychoses in the outpatient clinics of a tertiary psychiatric hospital were analyzed. The Drug Abuse Screening Test (DAST-10) was used to assess problematic drug use. Information on sociodemographics, smoking status, alcohol use, symptoms severity and quality of life were collected. Multivariable logistic regressions were conducted to explore correlates and associations of problematic drug use. Results: The prevalence of problematic drug use was 5.8% (n = 23) in the sample, and 10.6% (n = 42) of the participants reported having problematic drug use and/or problematic alcohol use. More males than females reported having problematic drug use (p = 0.021), and also problematic drug and/or alcohol use (p = 0.004). Significant associations were observed between problematic drug use and smokers with nicotine dependence, and with physical health domain of quality of life. Individuals with greater symptom severity were approximately twice as likely to have problematic drug use and/or alcohol use. Conclusion: While the prevalence of problematic drug use in this sample population is relatively lower compared to other countries, there is a considerable number who might be at risk. Routine screening and close monitoring of drug use is recommended as part of psychiatric assessment, particularly among males and patients with nicotine dependence.

Long-term outcome of early-onset compared to adult-onset schizophrenia: A nationwide Danish register study

OBJECTIVE

Early-onset schizophrenia (EOS) may have worse outcomes than adult-onset schizophrenia (AOS), but data are scarce. We compared outcomes of EOS vs. AOS.

METHODS

Longitudinal, register-based study of patients diagnosed with schizophrenia in Denmark between 1996 and 2012, with follow-up until 12/2014. Co-primary outcomes were psychiatric inpatient days during the initial two years after schizophrenia diagnosis and mean number of annual inpatient days for the remaining follow-up.

RESULTS

Altogether, 16,337 patients with schizophrenia were included (EOS = 1223, AOS = 15,114, mean follow-up = 9.5 ± 5.0 years). EOS were hospitalized longer during the first two years than AOS (180.9 ± 171.0 vs 163.4 ± 183.1 days, p < 0.005; IRR = 1.27, 95% CI = 1.19-1.35, p < 0.001), but duration and annual rates thereafter did not differ (EOS = 26.8 ± 57.1 days, AOS = 26.6 ± 56.2 days, p = 0.95; IRR = 1.07, 95% CI = 0.94-1.23, p = 0.30). Fewer EOS patients were never psychiatrically hospitalized (EOS = 17.2%, AOS = 20.1%, p < 0.001), but with no difference in re-admissions in patients diagnosed during hospitalization (EOS = 77.1% vs AOS = 78.1%, p = 0.56). More EOS patients were admitted involuntarily (41% vs. 36%, p < 0.02). AOS patients had more often comorbid substance use disorders during follow-up than EOS (EOS = 21.7%, AOS = 34.2%, p < 0.001). Substance use disorders and out-of-home placement were significantly associated with more inpatient days during both short- and long-term follow-up.

CONCLUSION

Although EOS was associated with more inpatient days in the first two years after diagnosis, results do not seem to support a generally poorer long-term outcome of EOS compared to AOS. Longer initial hospitalization may be driven by different treatment patterns in child and adolescent vs. adult psychiatry. These data suggest that patient characteristics other than age of onset significantly affect outcomes.

Differential effects of Δ9-tetrahydrocannabinol dosing on correlates of schizophrenia in the sub-chronic PCP rat model

Social withdrawal in the sub-chronic phencyclidine (PCP) rat model, a behavioral correlate of the negative symptoms of schizophrenia, results from deficits in brain endocannabinoid transmission. As cannabis intake has been shown to affect negatively the course and expression of psychosis, we tested whether the beneficial effects of endocannabinoid-mediated CB₁ activation on social withdrawal in PCP-treated rats (5 mg/kg, twice daily for 7 days)also occurred after administration of Δ9-tetrahydrocannabinol (THC; 0.1, 0.3, 1.0 mg/kg, i.p.). In addition, we assessed whether THC affected two correlates of positive symptoms: 1) motor activity induced by d-amphetamine (0.5 mg/kg, i.p.), and 2) dopamine neuron population activity in the ventral tegmental area (VTA). After the motor activity test, the brains from d-amphetamine-treated animals were collected and processed for measurements of endocannabinoids and activation of Akt/GSK3β, two molecular markers involved in the pathophysiology of schizophrenia. In control rats, THC dose-dependently produced social interaction deficits and aberrant VTA dopamine neuron population activity similar to those observed in PCP-treated animals. In PCP-treated rats, only the lowest dose of THC reversed PCP-induced deficits, as well as PCP-induced elevation of the endocannabinoid anandamide (AEA) in the nucleus accumbens. Last, THC activated the Akt/GSK3β pathway dose-dependently in both control and PCP-treated animals. Taken together, these data suggest that only low doses of THC have beneficial effects on behavioral, neurochemical and electrophysiological correlates of schizophrenia symptoms. This observation may shed some light on the controversial hypothesis of marijuana use as self-medication in schizophrenic patients.

A health promotion intervention to improve lifestyle choices and health outcomes in people with psychosis: a research programme including the IMPaCT RCT

Background

People with psychotic disorders have reduced life expectancy largely because of physical health problems, especially cardiovascular disease, that are complicated by the use of tobacco and cannabis.

Objectives

We set out to (1) chart lifestyle and substance use choices and the emergence of cardiometabolic risk from the earliest presentation with psychosis, (2) develop a pragmatic health promotion intervention integrated within the clinical teams to improve the lifestyle choices and health outcomes of people with psychosis and (3) evaluate the clinical effectiveness and cost-effectiveness of that health promotion intervention.

Design

We performed a longitudinal cohort study of people presenting with their first episode of psychosis in three mental health trusts and followed up participants for 1 year [work package 1, physical health and substance use measures in first episode of psychosis (PUMP)]. We used an iterative Delphi methodology to develop and refine a modular health promotion intervention, improving physical health and reducing substance use in psychosis (IMPaCT) therapy, which was to be delivered by the patient’s usual care co-ordinator and used motivational interviewing techniques and cognitive–behavioural therapy to improve health choices of people with psychosis (work package 2). We then conducted a multicentre, two-arm, parallel-cluster, randomised controlled trial to determine the clinical effectiveness and cost-effectiveness of using the intervention with people with established psychosis (work package 3: IMPaCT randomised controlled trial) in five UK mental health trusts. The work took place between 2008 and 2014.

Participants

All people aged between 16 and 65 years within 6 months of their first presentation with a non-organic psychosis and who were proficient in English were eligible for inclusion in the PUMP study. Participants in the work package 2 training development were staff selected from a range of settings, working with psychosis. Participants in the phase 3 Delphi consensus and manual development comprised three expert groups of (1) therapists/researchers recruited from the local and national community, (2) clinicians and (3) service users, each of whom took part in two iterative review and feedback sessions. For work package 3, IMPaCT randomised controlled trial, care co-ordinators in participating community mental health teams who were permanently employed and had a minimum of four eligible patients (i.e. aged between 18 and 65 years with a diagnosis of a psychotic disorder) on their caseload were eligible to participate. In studies 1 and 3, patient participants were ineligible if they were pregnant or had a major illness that would have had an impact on their metabolic status or if they had a significant learning disability. All participants were included in the study only after giving written confirmed consent.

Main outcome measures

Cardiometabolic risk markers, including rates of obesity and central obesity, and levels of glycated haemoglobin (HbA1c) and lipids, were the main outcomes in work package 1 (PUMP), with descriptive data presented on substance use. Our primary outcome measure for the IMPaCT randomised controlled trial was the physical or mental health component Short Form questionnaire-36 items quality-of-life scores at 12 months.

Results

Obesity rates rose from 18% at first presentation with psychosis to 24% by 1 year, but cardiometabolic risk was not associated with baseline lifestyle and substance use choices. Patterns of increase in the levels of HbA1c over the year following first presentation showed variation by ethnic group. We recruited 104 care co-ordinators, of whom 52 (with 213 patients) were randomised to deliver IMPaCT therapy and 52 (with 193 patients) were randomised to deliver treatment as usual, in keeping with our power calculations. Of these 406 participants with established psychosis, 318 (78%) and 301 (74%) participants, respectively, attended the 12- and 15-month follow-ups. We found no significant effect of IMPaCT therapy compared with treatment as usual on the physical or mental health component Short Form questionnaire-36 items scores at either time point in an intention-to-treat analysis [physical health score (‘d’) –0.17 at 12 months and –0.09 at 15 months; mental health score (‘d’) 0.03 at 12 months and –0.05 at 15 months] or on costs. Nor did we find an effect on other cardiovascular risk indicators, including diabetes, except in the case of high-density lipoprotein cholesterol, which showed a trend for greater benefit with IMPaCT therapy than with treatment as usual (treatment effect 0.085, 95% confidence interval 0.007 to 0.16; p = 0.034).

Limitations

Follow-up in work package 1 was challenging, with 127 out of 293 participants attending; however, there was no difference in cardiometabolic measures or demographic factors at baseline between those who attended for follow-up and those who did not. In work package 3, the IMPaCT randomised controlled trial, care co-ordinators struggled to provide additional time to their patients that was devoted to the health promotion intervention on top of their usual clinical care contact with them.

Conclusions

Cardiometabolic risk is prominent even soon after first presentation with psychosis and increases over time. Lifestyle choices and substance use habits at first presentation do not predict those who will be most cardiometabolically compromised 1 year later. Training and supervising care co-ordinators to deliver a health promotion intervention to their own patients on top of routine care is not effective in the NHS for improving quality of life or reducing cardiometabolic risk.

Future work

Further work is needed to develop and evaluate effective, cost-effective and affordable ways of preventing the emergence of and reversing existing cardiometabolic risk indicators in people with psychosis.

Trial registration

Current Controlled Trials ISRCTN58667926.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 8, No. 1. See the NIHR Journals Library website for further project information.

Cannabidiol Improves Cognitive Impairment and Reverses Cortical Transcriptional Changes Induced by Ketamine, in Schizophrenia-Like Model in Rats

Cannabidiol (CBD), a non-psychotropic cannabinoid, demonstrates antipsychotic-like and procognitive activities in humans and in animal models of schizophrenia. The mechanisms of these beneficial effects of CBD are unknown. Here, we examined behavioral effects of CBD in a pharmacological model of schizophrenia-like cognitive deficits induced by repeated ketamine (KET) administration. In parallel, we assessed transcriptional changes behind CBD activities in the prefrontal cortex (PFC), the main brain area linked to schizophrenia-like pathologies. Male Sprague-Dawley rats were injected for 10 days with KET followed by 6 days of CBD. The cognitive performance was evaluated in the novel object recognition test followed by PFC dissections for next-generation sequencing (RNA-Seq) analysis and bioinformatics. We observed that KET-induced learning deficits were rescued by CBD (7.5 mg/kg). Similarly, CBD reversed transcriptional changes induced by KET. The majority of the genes affected by KET and KET-CBD were allocated to astroglial and microglial cells and associated with immune-like processes mediating synaptogenesis and neuronal plasticity. These genes include C1qc, C1qa, C1qb, C2, and C3 complement cascade elements, Irf8 factor and Gpr84, Gpr34, Cx3cr1, P2ry12, and P2ry6 receptors. The main pathway regulators predicted to be involved included TGFβ1 and IFNγ. In addition, CBD itself upregulated oxytocin mRNA in the PFC. The present data suggest that KET induces cognitive deficits and transcriptional changes in the PFC and that both effects are sensitive to a reversal by CBD treatment.

Recent violence and legal involvement among young adults with early psychosis enrolled in Coordinated Specialty Care

AIM

Individuals with serious mental illnesses have a small increased risk of engaging in violence or legal involvement compared to the general population. This seems to be particularly true for young adults experiencing early stages of psychosis. This study analysed the prevalence of and risk factors for reports of violence and legal involvement in a sample of young adults receiving Coordinated Specialty Care for early non-affective psychosis.

METHODS

A total of 373 young adults (ages 16-30) within 2 years of the onset of non-affective psychosis were enrolled in 10 Coordinated Specialty Care sites in New York State from October 2013 to August 2016. Baseline violent ideation or behaviour and legal involvement was described and predictors identified.

RESULTS

Approximately one-quarter of individuals had either recent violent ideation or behaviour at baseline (n = 90, 24.6%); nearly one-tenth of the sample reported recent legal involvement (n = 33, 9.0%). Individuals with violent ideation or behaviour had lower levels of education and were less likely to be working. Those with recent legal involvement were more likely to be male and more likely to have substance use (alcohol, cannabis and other drugs).

CONCLUSIONS

The overall rate of recent violent ideation or behaviour is similar to other studies; up to one-third of individuals experiencing a first-episode of psychosis (FEP) report violence. Recent legal involvement was strongly associated with substance use. This study presents insight into violence and legal involvement among individuals with FEP and indicates the need for further research.

Individuals with psychosis and a lifetime history of cannabis use show greater deficits in emotional experience compared to non-using peers

Background: While previous research suggests that active cannabis use is a barrier to the emotional experiences of anticipating pleasure and expressing emotion in early psychosis, the relationship between lifetime cannabis use, emotional experience and social function over time has been understudied.Aims: This study sought to characterize the influence of lifetime cannabis use on emotional experience in prolonged psychosis and the influence of the interaction of cannabis use and emotional expression on social function.Methods: Emotional expression, experience of pleasure in the moment, anticipatory anhedonia and social functioning were measured concurrently using the Emotional Expressivity Scale (EES), Temporal Experience of Pleasure Scale (TEPS) and Social Functioning Scale (SFS), respectively. Participants were adults with schizophrenia either with (n = 35) or without (n = 36) a lifetime history of cannabis use.Results: Compared to non-using participants, individuals with a history of cannabis use expressed lesser abilities to express emotion, were less likely to expect pleasure and had poorer social function. Cannabis use moderated the relationship between anticipatory pleasure and prosocial activities.Conclusions: Lifetime cannabis use in schizophrenia may be associated with greater deficits in emotional expressivity, anticipation of pleasure and social function. Cannabis use may disrupt the relationship between anticipatory pleasure and social functioning.

Early Substance Use Cessation Improves Cognition-10 Years Outcome in First-Episode Psychosis Patients

Background: Cognitive impairment may be a risk factor for, as well as a consequence of, psychosis. Non-remitting symptoms, premorbid functioning, level of education, and socioeconomic background are known correlates. A possible confounder of these associations is substance use, which is common among patients with psychosis and linked to worse clinical outcomes. Studies however show mixed results for the effect of substance use on cognitive outcomes. In this study, the long-term associations of substance use with cognition in a representative sample of first-episode psychosis patients were examined. Methods: The sample consisted of 195 patients. They were assessed for symptom levels, function, and neurocognition at 1, 2, 5, and 10 years after first treatment. Test scores were grouped into factor analysis-based indices: motor speed, verbal learning, visuomotor processing, verbal fluency, and executive functioning. A standardized composite score of all tests was also used. Patients were divided into four groups based on substance-use patterns during the first 2 years of treatment: persistent users, episodic users, stop-users, and nonusers. Data were analyzed using linear mixed effects modeling. Results: Gender, premorbid academic functioning, and previous education were the strongest predictors of cognitive trajectories. However, on motor speed and verbal learning indices, patients who stopped using substances within the first 2 years of follow-up improved over time, whereas the other groups did not. For verbal fluency, the longitudinal course was parallel for all four groups, while patients who stopped using substances demonstrated superior performances compared with nonusers. Persistent users demonstrated impaired visuomotor processing speed compared with nonusers. Within the stop- and episodic use groups, patients with narrow schizophrenia diagnoses performed worse compared with patients with other diagnoses on verbal learning and on the overall composite neurocognitive index. Discussion: This study is one of very few long-term studies on cognitive impairments in first-episode psychosis focusing explicitly on substance use. Early cessation of substance use was associated with less cognitive impairment and some improvement over time on some cognitive measures, indicating a milder illness course and superior cognitive reserves to draw from in recovering from psychosis.

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.

Clinical and functional outcomes of cannabis use among individuals with anxiety disorders: A 3-year population-based longitudinal study

BACKGROUND

Cannabis use has been reported to negatively affect the course and outcome of various psychiatric disorders, yet little is known on its effect on rates of remission from anxiety disorders and associated clinical and functional outcomes.

METHODS

In this study, data were drawn from Waves 1 and 2 of the National Epidemiologic survey on Alcohol and Related Conditions, focusing on individuals who qualified for a diagnosis of any anxiety disorder (social anxiety, panic disorder, generalized anxiety disorder, and specific phobias) at Wave 1 (N = 3,723). Cannabis users and individuals with cannabis use disorders (CUDs) throughout a 4-year period were compared to nonusers in rates of remission, suicidality, general functioning, and quality of life at Wave 2, while controlling for baseline confounders.

RESULTS

Although rates of remission decreased with level of cannabis use, this was not maintained in adjusted models. Aside from specific outcomes (individuals with CUDs were significantly more prone to report breaking up from a romantic relationship; adjusted odds ratio [AOR] = 3.85, 95% confidence interval [CI] = 1.66-8.97) and repeatedly quitting school (AOR = 6.02, 95% CI = 2.65-13.66)), following adjustment no additional differences were found in outcome measures.

CONCLUSIONS

These findings add to previous reports suggesting that poorer outcome of anxiety disorders among cannabis users may be attributed mainly to differences in baseline factors and not cannabis use.

Demographic and clinical correlates of substance use disorders in first episode psychosis

BACKGROUND

We assessed the prevalence and correlates of lifetime substance use disorders in people with first episode psychosis using the baseline data from the Recovery After an Initial Schizophrenia Episode (RAISE) Early Treatment Program study.

METHODS

Research staff assessed 404 first episode patients at 34 community mental health centers across the United States with the Structured Clinical Interview for DSM-IV for diagnoses of psychotic and substance use disorders. Logistic regression was used to evaluate the relationships between participant characteristics and lifetime substance use disorders, followed with generalized linear mixed-effects regression models to identify unique predictors of lifetime substance use disorders.

RESULTS

Approximately one-third of participants reported recent alcohol use (36.6%) and cannabis use (30.7%), and one half (51.7%) met criteria for any lifetime alcohol or drug use disorder. Lifetime substance use disorders were associated with male gender, White race, higher excited (hyperactivity, mood lability, impulsivity, hostility, and uncooperativeness), psychotic and depressive symptoms, less impaired cognition, and greater perceived stigma. Gender, race, and excited symptoms were the most consistent unique predictors of lifetime substance use disorders found in multivariate analyses.

CONCLUSIONS

Half of first episode psychosis patients have co-occurring substance use disorders, which are associated with both more severe symptoms and greater perceptions of stigma. Programs aiming to serve these patients must have the skills and clinical strategies to help people with these unique characteristics.

Meta-analysis of neurocognition in young psychosis patients with current cannabis use

OBJECTIVE

Adult psychosis patients (i.e. over the age of 25 years) who are also lifetime cannabis users (CANN±) appear to exhibit superior cognition compared to never-using patients (CANN-). The objective of this meta-analysis was to evaluate the cognitive differences between CANN- and patients who currently use cannabis (CANN+) (i.e. during the CANN± patients' cannabis-using stage). Specifically, focusing on young patients under the age of 25 years, the typical stage of both psychosis- and cannabis-onset.

METHOD

Of the 308 studies identified through database searches and secondary referencing, 14 compared neurocognition of CANN+ and CANN- in young people with psychotic disorders (mean age between 15 and 45 years). Effect sizes were extracted using neurocognitive test performance between CANN+ and CANN- and random effects modelling was conducted on pooled ES and moderator analyses.

RESULTS

CANN+ performed worse on several cognitive domains (i.e. premorbid IQ, current IQ, verbal learning, verbal working memory, motor inhibition) compared to CANN-. The association between age and performance in CANN+ cognition was varied, with older age predictive of worse performance in processing speed, sustained attention, verbal memory, and better performance in verbal learning and very fluency. Of note, CANN+ outperformed CANN- in tests of conceptual set-shifting.

CONCLUSION

These results are consistent with previous findings indicating that CANN+ demonstrate poorer neurocognition than CANN-; and that this is exacerbated with increasing age. Our findings demonstrate significant cognitive differences between patients with CANN+ versus CANN- even at early-onset psychosis, which could suggest a different underlying mechanism towards psychosis for cannabis users.

Comparing the effect of clozapine and risperidone on cue reactivity in male patients with schizophrenia and a cannabis use disorder: A randomized fMRI study

OBJECTIVE

Cannabis use disorders (CUDs) are highly comorbid in patients with schizophrenia and associated with poor outcome. Clozapine has been put forward as the first choice antipsychotic in this patient group. However, little is known about the mechanisms underlying the assumed superiority of clozapine.

METHODS

A total of 38 patients with DSM-IV schizophrenia (30 with and 8 without a DSM-IV CUD) and 20 healthy comparison subjects were included between April 2009 and June 2012. Patients were randomized to antipsychotic treatment with clozapine or risperidone. At baseline and after 4weeks of medication, brain response to cannabis-related, positive and neutral images was measured using functional MRI. Neural correlates of cue reactivity were assessed in the following regions of interest: amygdala, ventral striatum, insula, thalamus, orbitofrontal cortex and anterior cingulate cortex. Subjective craving was assessed using self-report questionnaires (OCDUS and MCQ).

RESULTS

At baseline, patients with a comorbid CUD showed higher subjective craving and greater activation in response to cannabis-related images compared to patients without a CUD and healthy controls in most regions of interest. Clozapine treated patients reported a greater reduction in craving (F(1,28)=6.0, p=0.04) and showed a larger decrease in amygdala activation during cannabis-related images compared to risperidone treated patients (T=3.94, pFWE=0.006). In addition, significant correlations were found between subjective craving and thalamus and insula activation during cannabis-related images.

CONCLUSION

These findings provide evidence that clozapine is superior to risperidone in decreasing subjective craving and cue reactivity for cannabis-related images probably due to a differential effect on dopaminergic neurotransmission.

TRIAL REGISTRATION

'Nederlands trial register' (http://www.trialregister.nl), nr NTR1761, http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1761.

The Potential of Cannabidiol Treatment for Cannabis Users With Recent-Onset Psychosis

A major factor associated with poor prognostic outcome after a first psychotic break is cannabis misuse, which is prevalent in schizophrenia and particularly common in individuals with recent-onset psychosis. Behavioral interventions aimed at reducing cannabis use have been unsuccessful in this population. Cannabidiol (CBD) is a phytocannabinoid found in cannabis, although at low concentrations in modern-day strains. CBD has a broad pharmacological profile, but contrary to ∆9-tetrahydrocannabinol (THC), CBD does not activate CB1 or CB2 receptors and has at most subtle subjective effects. Growing evidence indicates that CBD acts as an antipsychotic and anxiolytic, and several reports suggest neuroprotective effects. Moreover, CBD attenuates THC's detrimental effects, both acutely and chronically, including psychotogenic, anxiogenic, and deleterious cognitive effects. This suggests that CBD may improve the disease trajectory of individuals with early psychosis and comorbid cannabis misuse in particular-a population with currently poor prognostic outcome and no specialized effective intervention.

Psychotic patients who used cannabis frequently before illness onset have higher genetic predisposition to schizophrenia than those who did not

BACKGROUND

Schizophrenia (SZ) and bipolar disorder (BD) are heritable, polygenic disorders with shared clinical and genetic components, suggesting a psychosis continuum. Cannabis use is a well-documented environmental risk factor in psychotic disorders. In the current study, we investigated the relationship between SZ genetic load and cannabis use before illness onset in SZ and BD spectrums. Since frequent early cannabis use (age <18 years) is believed to increase the risk of developing psychosis more than later use, follow-up analyses were conducted comparing early use to later use and no use.

METHODS

We assigned a SZ-polygenic risk score (PGRS) to each individual in our independent sample (N = 381 SZ spectrum cases, 220 BD spectrum cases and 415 healthy controls), calculated from the results of the Psychiatric Genomics Consortium (PGC) SZ case-control study (N = 81 535). SZ-PGRS in patients who used cannabis weekly to daily in the period before first illness episode was compared with that of those who never or infrequently used cannabis.

RESULTS

Patients with weekly to daily cannabis use before illness onset had the highest SZ-PGRS (p = 0.02, Cohen's d = 0.33). The largest difference was found between patients with daily or weekly cannabis use before illness onset <18 years of age and patients with no or infrequent use of cannabis (p = 0.003, Cohen's d = 0.42).

CONCLUSIONS

Our study supports an association between high SZ-PGRS and frequent cannabis use before illness onset in psychosis continuum disorders.

Primary psychosis with comorbid drug abuse and drug-induced psychosis: Diagnostic and clinical evolution at follow up

The study reports a follow-up assessment of 48 patients with concomitant drug abuse at the first admission for psychosis. We focused on the diagnostic distinction between primary psychosis with concomitant drug abuse and drug induced psychosis, to observe whether the diagnoses are stable over time and whether the clinical course significantly differs. The study examined 25 primary psychotic disorder with comorbid drug abuse and 23 drug-induced psychotic disorder patients. Diagnostic and psychopathological assessments were made at baseline and at follow-up. Mean follow-up period was 4.96 years. Patients with comorbid Drug Abuse exhibited higher scores in the item Unusual Content of Thought at baseline than drug-induced psychotic disorder patients: 5.48 vs 4.39 while the two patients groups did not differ in any of the BPRS items evaluated at follow-up. The primary psychosis with comorbid drug abuse and the substance induced psychosis groups were similar regarding diagnostic stability, and a diagnosis of schizophrenia at follow-up occurred similarly. There was no evidence that Drug Induced psychotic patients' symptoms tend to improve more after cessation of drug abuse. An earlier age of onset was found in primary psychotic patients, particularly for patients diagnosed as affected by schizophrenia at follow up. These results might reflect the uncertainty of the distinction between Primary and Drug Induced Psychosis and the difficulties in applying the DSM IV-TR criteria for diagnosing comorbid drug use disorders and psychotic disorders.

Specific impact of stimulant, alcohol and cannabis use disorders on first-episode psychosis: 2-year functional and symptomatic outcomes

BACKGROUND

Many studies have concluded that cannabis use disorder (CUD) negatively influences outcomes in first-episode psychosis (FEP). However, few have taken into account the impact of concurrent misuse of other substances.

METHODS

This 2-year, prospective, longitudinal study of FEP patients, aged between 18 and 30 years, admitted to early intervention programs in Montreal, Quebec, Canada, examined the specific influence of different substance use disorders (SUD) (alcohol, cannabis, cocaine, amphetamines) on service utilization, symptomatic and functional outcomes in FEP.

RESULTS

Drugs and alcohol were associated with lower functioning, but drugs had a greater negative impact on most measures at 2-year follow-up. Half of CUD patients and more than 65% of cocaine or amphetamine abusers presented polysubstance use disorder (poly-SUD). The only group that deteriorated from years 1 to 2 (symptoms and functioning) were patients with persistent CUD alone. Outcome was worse in CUD than in the no-SUD group at 2 years. Cocaine, amphetamines and poly-SUD were associated with worse symptomatic and functional outcomes from the 1st year of treatment, persisting over time with higher service utilization (hospitalization).

CONCLUSION

The negative impact attributed to CUD in previous studies could be partly attributed to methodological flaws, like including polysubstance abusers among cannabis misusers. However, our investigation confirmed the negative effect of CUD on outcome. Attention should be paid to persistent cannabis misusers, since their condition seems to worsen over time, and to cocaine and amphetamine misusers, in view of their poorer outcome early during follow-up and high service utilization.

Poor medication adherence and risk of relapse associated with continued cannabis use in patients with first-episode psychosis: a prospective analysis

BACKGROUND

Cannabis use following the onset of first-episode psychosis has been linked to both increased risk of relapse and non-adherence with antipsychotic medication. Whether poor outcome associated with cannabis use is mediated through an adverse effect of cannabis on medication adherence is unclear.

METHODS

In a prospective analysis of data acquired from four different adult inpatient and outpatient units of the South London and Maudsley Mental Health National Health Service Foundation Trust in London, UK, 245 patients were followed up for 2 years from the onset of first-episode psychosis. Cannabis use after onset of psychosis was assessed by self-reports in face-to-face follow-up interviews. Relapse data were collected from clinical notes using the WHO Life Chart Schedule. This measure was also used to assess medication adherence on the basis of both face-to-face interviews and clinical notes. Patients were included if they had a diagnosis of first-episode non-organic or affective psychosis according to ICD-10 criteria, and were aged between 18 and 65 years when referred to local psychiatric services. We used structural equation modelling analysis to estimate whether medication adherence partly mediated the effects of continued cannabis use on risk of relapse. The primary outcome variable was relapse, defined as admission to a psychiatric inpatient unit after exacerbation of symptoms within 2 years of first presentation to psychiatric services. Information on cannabis use over the first 2 years after onset of psychosis was investigated as a predictor variable for relapse. Medication adherence was assessed as a mediator variable on the basis of clinical records and self-report data. Study researchers (TS, NP, EK, and EF) rated the adherence.

FINDINGS

397 patients who presented with their first episode of psychosis between April 12, 2002, and July 26, 2013 had a follow-up assessment until September, 2015. Of the 397 patients approached for followed up, 133 refused to take part in this study and 19 could not be included because of missing data. 91 (37%) of 245 patients with first-episode psychosis had a relapse over the 2 years of follow-up. Continued cannabis use predicted poor outcome, including risk of relapse, number of relapses, length of relapse, and care intensity at follow-up. In controlled structural equation modelling analyses, medication adherence partly mediated the effect of continued cannabis use on outcome, including risk of relapse (proportion mediated=26%, βindirect effects=0·08, 95% CI 0·004 to 0·16), number of relapses (36%, βindirect effects=0·07, 0·003 to 0·14), time until relapse (28%, βindirect effects=-0·26, -0·53 to 0·001) and care intensity (20%, βindirect effects=0·06, 0·004 to 0·11) but not length of relapse (6%, βindirect effects=0·03, -0·03 to 0·09). The adjusted models explained moderate amounts of variance for outcomes defined as risk of relapse (R2=0·25), number of relapses (R2=0·21), length of relapse (R2=0·07), time until relapse (R2=0·08), and care intensity index (R2=0·15).

INTERPRETATION

Between 20% and 36% of the adverse effects of continued cannabis use on outcome in psychosis might be mediated through the effects of cannabis use on medication adherence. Interventions directed at medication adherence could partly help mitigate the harm from cannabis use in psychosis.

FUNDING

This study is funded by the National Institute of Health Research (NIHR) Clinician Scientist award.

Cannabis use and adherence to antipsychotic medication: a systematic review and meta-analysis

BACKGROUND

Substance use may increase the risk of non-adherence to antipsychotics, resulting in negative outcomes in patients with psychosis.

METHOD

We aimed to quantitatively summarize evidence regarding the effect of cannabis use, the most commonly used illicit drug amongst those with psychosis, on adherence to antipsychotic medication. Studies were identified through a systematic database search. Adopting random-effects models, pooled odds ratios (OR) for risk of non-adherence to antipsychotic medications were calculated comparing: cannabis-users at baseline v. non-users at baseline; non users v. continued cannabis users at follow-up; non-users v. former users at follow-up; former users v. current users.

RESULTS

Fifteen observational studies (n = 3678) were included. Increased risk of non-adherence was observed for cannabis users compared to non-users (OR 2.46, n = 3055). At follow-up, increased risk of non-adherence was observed for current users compared to non-users (OR 5.79, n = 175) and former users (OR 5.5, n = 192), while there was no difference between former users and non-users (OR 1.12, n = 187).

CONCLUSIONS

Cannabis use increases the risk of non-adherence and quitting cannabis use may help adherence to antipsychotics. Thus, cannabis use may represent a potential target for intervention to improve medication adherence in those with psychosis.

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.

Cannabis use and the course and outcome of major depressive disorder: A population based longitudinal study

Cannabis use has been reported to affect the course of various psychiatric disorders, however its effect on the course of major depressive disorder (MDD) is not yet clear. We used data from Wave 1 and Wave 2 of the National Epidemiologic survey on Alcohol and Related Conditions (NESARC). Individuals with baseline MDD (N=2,348) were included in the study. Cannabis users without a Cannabis Use Disorder (CUDs) and individuals with a CUD were compared to nonusers using linear and logistic regression analyses controlling for sociodemographics, psychiatric disorders and substance use disorders at baseline. No differences were found in rates of remission between the groups. Level of cannabis use was associated with significantly more depressive symptoms at follow-up, particularly anhedonia, changes in body weight, insomnia or hypersomnia and psychomotor problems. After adjusting for baseline confounding factors, no associations were found between cannabis use and suicidality, functionality and quality of life. We conclude that many of the associations between cannabis use and a more severe course of MDD do not seem to be attributed to cannabis use itself but to associated sociodemographic and clinical factors. Further longitudinal studies using depression severity indices are required.

Cannabis use, COMT, BDNF and age at first-episode psychosis

Although an interaction between COMT Val158Met and BDNF Val66Met polymorphisms with cannabis use has been proposed with respect to the risk of psychosis emergence, findings remain inconclusive. The aim of the present study was to evaluate the different possible associations between these polymorphisms and early cannabis use and the age at the first episode of psychosis. The relationship between age at psychosis onset and COMT Val158Met and BDNF Val66Met polymorphisms with early cannabis use as well as those factors associated with early cannabis use were investigated. Among 260 Caucasian first-episode psychosis patients, early cannabis use and the presence of the met-allele from the BDNF Val66Met polymorphism were significantly associated with age at psychosis onset. Furthermore, early cannabis use was significantly associated with male gender in the logistic regression analysis. These findings provide evidence of the important role of early cannabis use and the Val66Met BDNF polymorphism on age at psychosis onset and they point out to sex-specific differences in cannabis use patterns.

Cannabidiol, among Other Cannabinoid Drugs, Modulates Prepulse Inhibition of Startle in the SHR Animal Model: Implications for Schizophrenia Pharmacotherapy

Schizophrenia is a severe psychiatric disorder that involves positive, negative and cognitive symptoms. Prepulse inhibition of startle reflex (PPI) is a paradigm that assesses the sensorimotor gating functioning and is impaired in schizophrenia patients as well as in animal models of this disorder. Recent data point to the participation of the endocannabinoid system in the pathophysiology and pharmacotherapy of schizophrenia. Here, we focus on the effects of cannabinoid drugs on the PPI deficit of animal models of schizophrenia, with greater focus on the SHR (Spontaneously Hypertensive Rats) strain, and on the future prospects resulting from these findings.

Polytobacco, marijuana, and alcohol use patterns in college students: A latent class analysis

Limited research has examined polysubstance use profiles among young adults focusing on the various tobacco products currently available. We examined use patterns of various tobacco products, marijuana, and alcohol using data from the baseline survey of a multiwave longitudinal study of 3418 students aged 18-25 recruited from seven U.S. college campuses. We assessed sociodemographics, individual-level factors (depression; perceptions of harm and addictiveness,), and sociocontextual factors (parental/friend use). We conducted a latent class analysis and multivariable logistic regression to examine correlates of class membership (Abstainers were referent group). Results indicated five classes: Abstainers (26.1% per past 4-month use), Alcohol only users (38.9%), Heavy polytobacco users (7.3%), Light polytobacco users (17.3%), and little cigar and cigarillo (LCC)/hookah/marijuana co-users (10.4%). The most stable was LCC/hookah/marijuana co-users (77.3% classified as such in past 30-day and 4-month timeframes), followed by Heavy polytobacco users (53.2% classified consistently). Relative to Abstainers, Heavy polytobacco users were less likely to be Black and have no friends using alcohol and perceived harm of tobacco and marijuana use lower. Light polytobacco users were older, more likely to have parents using tobacco, and less likely to have friends using tobacco. LCC/hookah/marijuana co-users were older and more likely to have parents using tobacco. Alcohol only users perceived tobacco and marijuana use to be less socially acceptable, were more likely to have parents using alcohol and friends using marijuana, but less likely to have friends using tobacco. These findings may inform substance use prevention and recovery programs by better characterizing polysubstance use patterns.

The Effects of Cannabis on Inpatient Agitation, Aggression, and Length of Stay

OBJECTIVE

This study examines the association between cannabis use and the hospital course of patients admitted to the psychiatric inpatient unit with a diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder. Many confounding variables potentially contribute to the clinical presentation of hospitalized patients in the psychiatric unit. Illicit drug use, in particular, has been associated with acute agitation, and questions can be raised as to what lasting effects drug use prior to admission may have throughout a patient's hospital stay.

METHODS

Subjects with a discharge diagnosis of bipolar disorder, schizophrenia, schizoaffective disorder, or psychosis not otherwise specified (N = 201) were retrospectively identified, and those with positive results of urine drug screen for cannabis on admission were compared to negative counterparts. Agitation and aggression were measured using an adaptation of the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC). These markers were also quantified by comparing charted episodes of restraint and seclusion and administration of as needed medications, such as benzodiazepines and antipsychotics.

RESULTS

Positive urine drug screen results for cannabis was correlated with young (p = .001) males (p = .003) with bipolar disorder (p = .009) exhibiting active manic symptoms (p = .003) at the time of admission. Cannabis use was further associated with a shorter length of stay (p = .008), agitation triggering adapted PANSS-EC nursing assessments (p = .029), and oral medications as needed (p = .002) for agitation.

CONCLUSIONS

Cannabis use, as defined by positive urine drug screen results, was more common in patients with bipolar disorder and was accompanied by a higher incidence of inpatient agitation. Although these patients also had short hospital lengths of stay, there was no clear relationship between level of agitation and length of stay across all patient groups. One possible explanation for patients with bipolar disorder experiencing short lengths of stay is that their source of agitation may be more closely related to a complex effect of cannabis use rather than a sole etiology of mental illness. Inpatient clinicians should be aware of patient cannabis use proximate to admission.

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.

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.

Antipsychotic efficacy in psychosis with co-morbid cannabis misuse: A systematic review

The prevalence of cannabis use in patients with psychotic mental illness is known to be high and is suspected to exacerbate symptoms and worsen prognosis. We aimed to evaluate evidence of antipsychotic efficacy in reducing the burden of psychotic symptoms and cannabis use in individuals with psychotic mental illness and co-morbid cannabis use. A systematic review was conducted of antipsychotic treatment in those with psychotic mental illness and co-morbid cannabis use. Quality of evidence for each study and outcomes were rated using the 'GRADE' approach. Twenty-two studies were identified: 13 experimental and 9 observational, including a total sample of 1543 patients, 761 of whom had a diagnosed cannabis use disorder. The most frequent antipsychotics compared were risperidone, olanzapine and clozapine with olanzapine, risperidone and haloperidol. No clear differences between antipsychotics were demonstrated. Future studies are needed to confirm whether clozapine is superior to other antipsychotics in reducing cannabis use.

Cannabis Use and Associated Harms among Schizophrenia Patients in a Nigerian Clinical Setting: A Case-Control Study

AIM

The overall aim of this study was to determine the prevalence of cannabis use among patients with schizophrenia with associated levels of harm in a Nigerian clinical setting.

METHOD

In this case-control study, consecutive 150 patients with schizophrenia were matched by age and gender with an equal number of patients that utilized the general outpatient department of the State Hospital, Ring Road Ibadan. The alcohol, smoking and substance involvement screening test (ASSIST) was used to obtain prevalence of cannabis use and level of health risk as determined by the ASSIST score. The positive and negative syndrome scale was used to determine the severity of psychosis.

RESULTS

Prevalence of cannabis use among the cases and control group was 10.0 and 2.7%, respectively, p = 0.03. Mean ASSIST score was significantly higher among the cases compared with the control, p < 0.001. Respondents of male gender and those who were not married were significantly more likely to be cannabis users among patients with schizophrenia (p < 0.001 and p < 0.02), respectively.

CONCLUSION

Cannabis use was prevalent among patients with schizophrenia and was associated with health risks. Thus, routine screening for cannabis use and brief intervention is suggested to be integrated into care for adolescents and adults with schizophrenia.

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.