Impact of comorbid cannabis use on outcome in first episode psychosis

Randomized Laboratory Study of Single-Dose Cannabis, Dronabinol, and Placebo in Patients With Schizophrenia and Cannabis Use Disorder

BACKGROUND AND HYPOTHESIS

Up to 43% of people with schizophrenia have a lifetime cannabis use disorder (CUD). Tetrahydrocannabinol (THC) has been shown to exacerbate psychosis in a dose-dependent manner, but little research has assessed its effects on schizophrenia and co-occurring CUD (SCZ-CUD). In this double-dummy, placebo-controlled trial (total n = 130), we hypothesized that a modest dose of THC would worsen cognitive function but not psychosis.

STUDY DESIGN

Effects of single-dose oral THC (15 mg dronabinol) or smoked 3.5% THC cigarettes vs placebo in SCZ-CUD or CUD-only on positive and negative symptoms of schizophrenia (only for SCZ-CUD), cognition, and drug experiences assessed several hours after drug administration. SCZ-only and healthy control participants were also assessed.

STUDY RESULTS

Drug liking was higher in THC groups vs placebo. Neither smoked THC nor oral dronabinol predicted positive or negative symptom subscale scores 2 and 5 h, respectively, after drug exposure in SCZ-CUD participants. The oral dronabinol SCZ-CUD group, but not smoked THC SCZ-CUD group, performed worse than placebo on verbal learning (B = -9.89; 95% CI: -16.06, -3.18; P = .004) and attention (B = -0.61; 95% CI: -1.00, -0.23; P = .002). Every 10-point increment in serum THC + THCC ng/ml was associated with increased negative symptoms (0.40 points; 95% CI: 0.15, 0.65; P = .001; subscale ranges 7-49) and trends were observed for worse positive symptoms and performance in verbal learning, delayed recall, and working memory.

CONCLUSIONS

In people with SCZ-CUD, a modest single dose of oral THC was associated with worse cognitive functioning without symptom exacerbation several hours after administration, and a THC dose-response effect was seen for negative symptoms.

Cannabis and psychopathology: 2024 Snapshot of a meandering journey

Background

Cannabis has been associated with psychopathology since ancient times, but controversies continue despite important advances in the field. This article is the fourth one in our decadal series of review articles that have been providing an update snapshot of the meandering journey of the research findings in this area.

Aims

This narrative review of a comprehensive literature search over the past 10 years aims to provide an update and current understanding, while raising unanswered questions for the future, focusing on the following areas: (a) nosological changes in cannabis-related psychiatric syndromes; (b) psychopathology associated with the newer category of synthetic cannabinoids; (c) cannabis withdrawal syndrome); (d) cannabis and psychosis; (e) cannabis and mood disorders; (f) cannabis and suicidality; (g) prenatal cannabis use and psychopathology in the offspring; (h) effect of recent liberal policy overhaul on cannabis control in certain countries/areas on psychopathology and adverse outcomes; (i) cannabis and cognition; and (j) cannabis, psychopathology, and genetics.

Methods

The data search strategies involved a combination of electronic databases and manual hand-searching of relevant publications and cross-references using selected search terms. The primary electronic search focused on Medline and PubMed Central databases but extended to databases such as Google Scholar, PsychINFO, Scopus, and Ovid for specific sections. Key references identified through electronic and manual searches provided additional material. Inclusion criteria for the review spanned studies published between January 2014 and June 2024, with more emphasis placed on recent studies (post-2020) while ensuring historical coverage.

Results

The narrative review aimed to be comprehensive, including a broad range of research without strict methodological exclusions. Strengths and limitations of cited research are discussed when applicable, maintaining consistency with three prior reviews. We focused on psychopathology and psychiatric syndromes, human (rather than animal) studies, and applied (rather than basic) research. We have only focused on policy with reference to psychopathology and not on that entire area because that would be beyond the scope of this article. There are important updates in all the areas covered. There are newer syndromal entities in ICD-11, which also includes synthetic cannabinoids for the first time. Cannabis withdrawal syndrome has been better characterized. The association between cannabis and psychosis has been robustly established especially for very high-potency cannabis and for vulnerable populations, particularly young people. Work is in progress elucidating the causal mechanisms. The links between cannabis and mood disorders as well as suicidality and cognitive impairment are better characterized, though questions remain. Recent liberalizing policies on cannabis have produced newer findings on prenatal and accidental cannabis use (with deleterious effects on the offspring) and on later psychopathology (mixed findings, but a documented increase in emergency visits related to recent cannabis use). This is an area which will require active monitoring for new data.

Conclusion

The field of cannabis use and psychopathology continues to collect new data and settle some old controversies while raising new questions, which are important to address in view of the wide use of cannabis worldwide and its implications for public health.

Psychosocial interventions for people with a first episode psychosis: between tradition and innovation

PURPOSE OF REVIEW

Assessing recent evidence on psychosocial interventions for people with first episode psychosis (FEP).

RECENT FINDINGS

Family interventions (FI) reduce relapse rates, whilst cognitive behavioural therapy (CBT) shows a moderate effect in improving positive psychotic symptoms. Vocational interventions (VI) appear to be worthy of implementation within early intervention for psychosis (EIP) teams, but it is still unclear what is the most cost-effective strategy for their delivery. Promising interventions, which need more careful evaluation, focus on substance misuse, physical health comorbidities, improvement of social participation, peer support and the potential of new technologies.

SUMMARY

The first five years after the onset of psychotic symptoms are a 'critical period' in which psychosocial interventions can be particularly influential in determining prognosis. Traditional EIP interventions have different effectiveness profiles, i.e., FI reduce relapse rates, CBT has a moderate effectiveness on overall and positive symptoms and VI can improve educational and employment-related functioning. Newer interventions show promise on important targets for FEP treatment but require higher-quality evaluations. Decisions on which interventions to implement within EIP teams should be informed by high-quality evidence, but difficult choices will have to be made based on costs, professionals and technologies available, and local priorities.

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.

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.

A systematic review of technology-based psychotherapeutic interventions for decreasing cannabis use in patients with psychosis

Persistent use of cannabis in persons with psychosis is associated with poor symptomatic and functional outcomes and increased healthcare costs. Face-to-face psychological interventions (e.g., Cognitive Behavioral Therapy- [CBT], Motivation Enhancement Therapy- [MET]) are widely used in treating problematic cannabis use. We aimed to comprehensively review the efficacy of technology-based psychological interventions (TBPIs) in decreasing cannabis use, the design of TBPIs, and TBPI-related preferences in individuals with psychosis. For the systematic review, we searched six major databases from their inception to November 27, 2019. We included empirical articles of quantitative and qualitative methodologies related to TBPIs in individuals with psychosis and cannabis misuse and used narrative synthesis to report results. Only eight articles were found showing that technology-based motivational and psycho-education interventions and cognitive enhancement therapy were minimally efficient in achieving cannabis abstinence or decreasing frequency of use. Qualitative exploratory methods and participatory action research were used to elicit patient and clinician preferences and TBPIs were tailored accordingly to improve cannabis use related outcomes. Research on TBPIs in individuals with psychosis and cannabis misuse is in its early phases. A significant research effort is needed for the development of adapted interventions for CUD to capitalize on the potential of web-based applications.

Association of smoked cannabis with treatment resistance in schizophrenia

Association of cannabis use with schizophrenia is a well-established finding. Its role in causation, however, is debated. Different studies have found that cannabis use impacts the outcome of schizophrenia and is associated with treatment non-adherence and a higher rate of relapses. In this paper, we investigated the impact of self-reported cannabis use on treatment response in a cohort of schizophrenia patients from Pakistan, a middle-income country. The data was collected from a psychiatric hospital in Khyber Pakhtunkhwa province of Pakistan where cannabis use is prevalent. Clinical evaluation and therapeutic response were established using the Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impressions Scales-Severity (CGI-S) and Improvement (CGI-I) scale. Lack of response to adequate treatment with two trials of antipsychotics was classed as treatment resistance. We compared the treatment-resistant and treatment responsive groups for different variables including cannabis use, age at onset of illness, duration of untreated psychosis and consanguinity. We had data on 230 patients. More than ninety percent of our participants were men. The rate of treatment resistance was over 60%. Ongoing use of cannabis had an association with treatment resistance. We only included cases where treatment adherence was not a problem.