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

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.

Use of antipsychotic medication, benzodiazepines, and psychiatric hospitalization in cannabis-related versus cannabis-unrelated schizophrenia - a nationwide, register-based cohort study

BACKGROUND

Evidence suggests that cannabis may be a causal factor for development of schizophrenia. We aimed to investigate whether use of antipsychotic medication, benzodiazepines, and psychiatric service use differs among patients with schizophrenia depending on whether psychosis was precipitated by a diagnosis of cannabis use disorder (CUD).

METHODS

We utilized the nationwide Danish registries to identify all individuals with an incident diagnosis of schizophrenia from 1995 to 2016. We also collected information on whether first CUD diagnosis preceded schizophrenia and thus defined a group of potentially cannabis-related schizophrenia. We compared the cannabis-related schizophrenia group both with all non-cannabis-related patients with schizophrenia and with non-cannabis-related patients with schizophrenia that were propensity-score matched to cases using a range of potentially confounding variables.

RESULTS

We included 35 714 people with incident schizophrenia, including 4116 (11.5%) that were cannabis-related. In the unmatched-comparison analyses, there were no clear differences over time in use of antipsychotics and benzodiazepines related to whether the diagnosis of schizophrenia was cannabis-related. After propensity-score matching, use of antipsychotics and benzodiazepines was significantly lower among cannabis-related cases of schizophrenia. In the unmatched comparison, the cannabis-related group had significantly more days admitted than the non-cannabis-related group. This was markedly attenuated after propensity-score matching.

CONCLUSIONS

Our findings indicate the importance of considering cannabis-related cases of schizophrenia as a potentially distinct disorder in terms of prognosis. It is unclear, however, if these differences are due to different biological types of schizophrenia being compared or if they rather indicate behavioral differences such as reduced adherence and treatment-seeking.

Relapse in schizophrenia: The role of factors other than non-adherence to treatment

AIM

Relapse rates are very high in schizophrenia. However, little is known about the predictors of the time to relapse other than treatment non-adherence. We investigated possible risk factors for the time to relapse in patients with first-episode schizophrenia (n = 107) who received assured treatment by way of long-acting injectable antipsychotic over 24 months and who underwent regular clinical, cognitive, and metabolic assessments.

METHODS

Using Cox regression analyses we assessed selected premorbid and baseline potential predictors of time to relapse. Relapse was defined using operationally defined relapse criteria.

RESULTS

In the primary analysis only neurological soft signs total score retained significance, with higher scores predicting shorter time to relapse (HR = 1.05, 95% CI = 1.01-1.10, p = .029). In a more detailed secondary analysis poorer social relationships predicted shorter time to relapse (HR = 0.85, 95% CI = 0.76-0.95, p = .003).

CONCLUSION

Our predominantly negative findings suggest that many of the previously implicated risk factors for the time to relapse are mediated by non-adherence rather than having a direct effect on relapse-proneness. Neurological soft signs, and perhaps quality of life in social relationships appear to play a role and merit further investigation.

Cannabis Use Frequency is Associated with PrEP Cessation and Self-reported HIV Diagnosis

To achieve stated targets in the United States of Ending the HIV Epidemic by 2030, it is necessary to decrease rates of pre-exposure prophylaxis use (PrEP) cessation. In particular, it is key to assess PrEP use and cannabis use frequency given the recent wave of cannabis decriminalization across the U.S., particularly among sexual minority men and gender diverse (SMMGD) individuals. We used data from the baseline visit of a national study of Black and Hispanic/Latino SMMGD. Among participants reporting any lifetime cannabis use, we further assessed the association between frequency of cannabis use in the past 3 months and: (1) self-reported PrEP use, (2) recency of last PrEP dose, and (3) HIV status using adjusted regression models. Compared to those who never used cannabis, odds of PrEP cessation were higher among those who used it once or twice (aOR 3.27; 95% CI 1.38, 7.78), those who used it monthly (aOR 3.41; 95% CI 1.06, 11.01), and those who used it weekly or more frequently (aOR 2.34; 95% CI 1.06, 5.16). Similarly, those reporting cannabis use 1-2 times in the past 3 months (aOR 0.11; 95% CI 0.02, 0.58) and those reporting weekly or more frequent use (aOR 0.14; 95% CI 0.03, 0.68) were each more likely to report more recent PrEP cessation. These results suggest that cannabis users in general may be a population at elevated risk of HIV diagnosis although more research regarding these findings is needed with nationally representative populations.

Unraveling ethnic disparities in antipsychotic prescribing among patients with psychosis: A retrospective cohort study based on electronic clinical records

BACKGROUND

Previous studies have shown mixed evidence on ethnic disparities in antipsychotic prescribing among patients with psychosis in the UK, partly due to small sample sizes. This study aimed to examine the current state of antipsychotic prescription with respect to patient ethnicity among the entire population known to a large UK mental health trust with non-affective psychosis, adjusting for multiple potential risk factors.

METHODS

This retrospective cohort study included all patients (N = 19,291) who were aged 18 years or over at their first diagnoses of non-affective psychosis (identified with the ICD-10 codes of F20-F29) recorded in electronic health records (EHRs) at the South London and Maudsley NHS Trust until March 2021. The most recently recorded antipsychotic treatments and patient attributes were extracted from EHRs, including both structured fields and free-text fields processed using natural language processing applications. Multivariable logistic regression models were used to calculate the odds ratios (OR) for antipsychotic prescription according to patient ethnicity, adjusted for multiple potential contributing factors, including demographic (age and gender), clinical (diagnoses, duration of illness, service use and history of cannabis use), socioeconomic factors (level of deprivation and own-group ethnic density in the area of residence) and temporal changes in clinical guidelines (date of prescription).

RESULTS

The cohort consisted of 43.10 % White, 8.31 % Asian, 40.80 % Black, 2.64 % Mixed, and 5.14 % of patients from Other ethnicity. Among them, 92.62 % had recorded antipsychotic receipt, where 24.05 % for depot antipsychotics and 81.72 % for second-generation antipsychotic (SGA) medications. Most ethnic minority groups were not significantly different from White patients in receiving any antipsychotic. Among those receiving antipsychotic prescribing, Black patients were more likely to be prescribed depot (adjusted OR 1.29, 95 % confidence interval (CI) 1.14-1.47), but less likely to receive SGA (adjusted OR 0.85, 95 % CI 0.74-0.97), olanzapine (OR 0.82, 95 % CI 0.73-0.92) and clozapine (adjusted OR 0.71, 95 % CI 0.6-0.85) than White patients. All the ethnic minority groups were less likely to be prescribed olanzapine than the White group.

CONCLUSIONS

Black patients with psychosis had a distinct pattern in antipsychotic prescription, with less use of SGA, including olanzapine and clozapine, but more use of depot antipsychotics, even when adjusting for the effects of multiple demographic, clinical and socioeconomic factors. Further research is required to understand the sources of these ethnic disparities and eliminate care inequalities.

Associations of comorbid substance use disorders with clinical outcomes in schizophrenia using electronic health record data

BACKGROUND AND HYPOTHESIS

Schizophrenia and comorbid substance use disorders (SUDs) are associated with poor treatment outcomes but differences between the associations of different SUDs with clinical outcomes are poorly characterized. This study examines the associations of comorbid SUDs with clinical outcomes in schizophrenia using a largescale electronic health record (EHR) database.

DESIGN

Real-world data (RWD) analysis using the NeuroBlu database; de-identified EHR data were analysed. Multivariable logistic regression, Poisson and CoxPH models were used to compare the associations of specific comorbid SUDs with outcome variables.

RESULTS

Comorbid SUD was significantly different on all outcome measures compared to no SUD (U = 1.44e7-1.81e7, all ps < .001), except number of unique antipsychotics (U = 1.61e7, p = .43). Cannabis (OR = 1.58, p < .001) and polysubstance (OR = 1.22, p = .007) use disorders were associated with greater CGI-S. Cannabis (IRR = 1.13, p = .003) and polysubstance (IRR = 1.08, p = .003) use disorders were associated with greater number of unique antipsychotics prescribed, while cocaine (HR = 1.87, p < .001), stimulants (HR = 1.64, p = .024), and polysubstance (HR = 1.46, p < .001) use disorders were associated with a shorter time to antipsychotic discontinuation. Conversely, alcohol use (IRR = 0.83, p < .001), cocaine use (IRR = 0.61, p < .001), opioid use (IRR = 0.61, p < .001), stimulant use (IRR = 0.57, p < .001) and polysubstance use (IRR = 0.87, p < .001) disorders were associated fewer inpatient days.

CONCLUSION

Comorbid SUDs were generally associated with greater CGI-S and poorer clinical outcomes in patients with schizophrenia. Treatment strategies should target not only schizophrenia symptoms but also comorbid SUD to improve management of both conditions.

Balancing risks and benefits of cannabis use: umbrella review of meta-analyses of randomised controlled trials and observational studies

OBJECTIVE

To systematically assess credibility and certainty of associations between cannabis, cannabinoids, and cannabis based medicines and human health, from observational studies and randomised controlled trials (RCTs).

DESIGN

Umbrella review.

DATA SOURCES

PubMed, PsychInfo, Embase, up to 9 February 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Systematic reviews with meta-analyses of observational studies and RCTs that have reported on the efficacy and safety of cannabis, cannabinoids, or cannabis based medicines were included. Credibility was graded according to convincing, highly suggestive, suggestive, weak, or not significant (observational evidence), and by GRADE (Grading of Recommendations, Assessment, Development and Evaluations) (RCTs). Quality was assessed with AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews 2). Sensitivity analyses were conducted.

RESULTS

101 meta-analyses were included (observational=50, RCTs=51) (AMSTAR 2 high 33, moderate 31, low 32, or critically low 5). From RCTs supported by high to moderate certainty, cannabis based medicines increased adverse events related to the central nervous system (equivalent odds ratio 2.84 (95% confidence interval 2.16 to 3.73)), psychological effects (3.07 (1.79 to 5.26)), and vision (3.00 (1.79 to 5.03)) in people with mixed conditions (GRADE=high), improved nausea/vomit, pain, spasticity, but increased psychiatric, gastrointestinal adverse events, and somnolence among others (GRADE=moderate). Cannabidiol improved 50% reduction of seizures (0.59 (0.38 to 0.92)) and seizure events (0.59 (0.36 to 0.96)) (GRADE=high), but increased pneumonia, gastrointestinal adverse events, and somnolence (GRADE=moderate). For chronic pain, cannabis based medicines or cannabinoids reduced pain by 30% (0.59 (0.37 to 0.93), GRADE=high), across different conditions (n=7), but increased psychological distress. For epilepsy, cannabidiol increased risk of diarrhoea (2.25 (1.33 to 3.81)), had no effect on sleep disruption (GRADE=high), reduced seizures across different populations and measures (n=7), improved global impression (n=2), quality of life, and increased risk of somnolence (GRADE=moderate). In the general population, cannabis worsened positive psychotic symptoms (5.21 (3.36 to 8.01)) and total psychiatric symptoms (7.49 (5.31 to 10.42)) (GRADE=high), negative psychotic symptoms, and cognition (n=11) (GRADE=moderate). In healthy people, cannabinoids improved pain threshold (0.74 (0.59 to 0.91)), unpleasantness (0.60 (0.41 to 0.88)) (GRADE=high). For inflammatory bowel disease, cannabinoids improved quality of life (0.34 (0.22 to 0.53) (GRADE=high). For multiple sclerosis, cannabinoids improved spasticity, pain, but increased risk of dizziness, dry mouth, nausea, somnolence (GRADE=moderate). For cancer, cannabinoids improved sleep disruption, but had gastrointestinal adverse events (n=2) (GRADE=moderate). Cannabis based medicines, cannabis, and cannabinoids resulted in poor tolerability across various conditions (GRADE=moderate). Evidence was convincing from observational studies (main and sensitivity analyses) in pregnant women, small for gestational age (1.61 (1.41 to 1.83)), low birth weight (1.43 (1.27 to 1.62)); in drivers, car crash (1.27 (1.21 to 1.34)); and in the general population, psychosis (1.71 (1.47 to 2.00)). Harmful effects were noted for additional neonatal outcomes, outcomes related to car crash, outcomes in the general population including psychotic symptoms, suicide attempt, depression, and mania, and impaired cognition in healthy cannabis users (all suggestive to highly suggestive).

CONCLUSIONS

Convincing or converging evidence supports avoidance of cannabis during adolescence and early adulthood, in people prone to or with mental health disorders, in pregnancy and before and while driving. Cannabidiol is effective in people with epilepsy. Cannabis based medicines are effective in people with multiple sclerosis, chronic pain, inflammatory bowel disease, and in palliative medicine but not without adverse events.

STUDY REGISTRATION

PROSPERO CRD42018093045.

FUNDING

None.

Cannabis Use and Symptomatic Relapse in First Episode Schizophrenia: Trigger or Consequence? Data From the OPTIMISE Study

BACKGROUND AND HYPOTHESIS

This analysis examined the relationship between cannabis use, compliance with antipsychotics and risk for relapse in patients in remission following a first episode of schizophrenia, schizophreniform, or schizoaffective disorder.

STUDY DESIGN

Analyses were performed on data from a large European study on first episode of schizophrenia, schizophreniform, or schizoaffective disorder (OPTiMiSE). After 10 weeks of antipsychotic treatment, 282/446 patients (63%) met criteria for symptomatic remission; of whom 134/282 (47.5%) then completed a 1-year follow-up. Cross-lagged models and mediation models investigated the temporal relationships between cannabis use, compliance with antipsychotics, social functioning, and symptomatic worsening/relapse.

STUDY RESULTS

Compared to nonusers, cannabis use increased risk for relapse, adjusted hazard ratio (HR) = 3.03 (SE = 0.32), P < .001, even in patients who were compliant with antipsychotic medication, adjusted HR = 2.89, (SE = 0.32), P < .001. Cannabis use preceded symptomatic worsening and was followed by worsening of Positive and Negative Syndrome Scale total score at the 1-year end-point (standardized β = 0.62, SE = 0.19, P = .001) and by worsening of social functioning (coef = -0.66, P ≤ .001).

CONCLUSIONS

In patients in remission from their first episode of schizophrenia, schizophreniform, or schizoaffective disorder, cannabis use increases the rate of relapse in both compliant and noncompliant individuals. Importantly, the temporal relationship between cannabis and relapse was that cannabis use preceded later relapse, noncompliance, and decrease in social functioning, and not that patients began to relapse, then used cannabis. Further research with a precision psychiatry approach might identify those patients in particular danger of relapse when using cannabis.

Recommendations for Reducing the Risk of Cannabis Use-Related Adverse Psychosis Outcomes: A Public Mental Health-Oriented Evidence Review

Objective: Cannabis use is increasingly normalized; psychosis is a major adverse health outcome. We reviewed evidence on cannabis use-related risk factors for psychosis outcomes at different stages toward recommendations for risk reduction by individuals involved in cannabis use. Methods: We searched primary databases for pertinent literature/data 2016 onward, principally relying on reviews and high-quality studies which were narratively summarized and quality-graded; recommendations were developed by international expert consensus. Results: Genetic risks, and mental health/substance use problem histories elevate the risks for cannabis-related psychosis. Early age-of-use-onset, frequency-of-use, product composition (i.e., THC potency), use mode and other substance co-use all influence psychosis risks; the protective effects of CBD are uncertain. Continuous cannabis use may adversely affect psychosis-related treatment and medication effects. Risk factor combinations further amplify the odds of adverse psychosis outcomes. Conclusions: Reductions in the identified cannabis-related risks factors-short of abstinence-may decrease risks of related adverse psychosis outcomes, and thereby protect cannabis users' health.

Discontinuing cannabis use: Symptomatic and functional outcomes in people with an established psychotic disorder

For people with psychotic disorders, the negative outcomes associated with continuing cannabis use would suggest that discontinuing such use may be beneficial for their symptomatic and functional recovery. However, existing evidence that discontinuation is associated with better clinical outcomes is inconsistent and it remains unclear whether discontinuing use is associated with improvements in outcomes for people with an established psychotic disorder. In this 3-5-year longitudinal study we examined baseline and follow-up symptomatic and functional profiles of 371 people with an established psychotic disorder, comparing those who continued to use cannabis with those who discontinued use after baseline assessment. At follow-up, one third (33.3 %) of baseline cannabis users had discontinued use. Discontinuation was associated with significantly lower odds of past-year hallucinations and a mean improvement in level of functioning (Personal and Social Performance Scale) compared to a decline in functioning in continuing users. No significant differences in severity of negative symptoms were observed. With few longitudinal studies examining symptomatic and functional outcomes for people with established psychotic disorders who continue to use cannabis compared to those who discontinue use, our findings that discontinuing cannabis was associated with significant clinical improvements fill gaps in the evidence-base.

Prevalence of cannabis use in people with psychosis in KwaZulu-Natal, South Africa

Background

There is a high prevalence of cannabis use in patients with schizophrenia spectrum and other psychotic disorders, with comorbid cannabis use in this population being associated with poorer long-term outcomes.

Aim

To determine the prevalence of cannabis use in patients with a schizophrenia spectrum and other psychotic disorders.

Setting

The study was conducted at a psychiatric hospital in Durban, KwaZulu-Natal Province, South Africa.

Methods

A review of clinical records of patients admitted to the hospital for the period, June 2018 to June 2020, was conducted.

Results

A total of 370 clinical records were reviewed, of which 48.9% reported current and 51.1% lifetime cannabis use. Being male was significantly associated with current and lifetime cannabis use (OR = 4.90, 95% CI 2.49–9.62 and OR = 6.27, 95% CI 3.28–11.95, respectively). Current alcohol use was also associated with current cannabis use (CCU) (OR = 3.06, 95% CI 1.78–5.28), and age 45 years and older was associated with a lower odds of cannabis use (OR = 0.30, 95% CI 0.09–0.96). Forty-eight per cent of participants were admitted three or more times, and readmission was associated with cannabis use (p = 0.01). There was a lack of association between cannabis use, readmission and human immunodeficiency virus (HIV) status, after controlling for variables such as alcohol use and gender.

Conclusion

Almost 50% of people admitted with schizophrenia spectrum and other psychotic disorders have comorbid current and lifetime cannabis use. There is a need for dual diagnosis units to address comorbid substance use in people with psychotic disorders, as it leads to poorer outcomes.

Contribution

The study found that there is a high prevalence of cannabis use in people with psychosis. Therefore, it is imperative that we revise treatment programs in our psychiatric units and there is an urgent need for dual diagnosis programs that address substance use in this group of patients.

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

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

Mortality in people with schizophrenia: a systematic review and meta-analysis of relative risk and aggravating or attenuating factors

People with schizophrenia die 15-20 years prematurely. Understanding mortality risk and aggravating/attenuating factors is essential to reduce this gap. We conducted a systematic review and random-effects meta-analysis of prospective and retrospective, nationwide and targeted cohort studies assessing mortality risk in people with schizophrenia versus the general population or groups matched for physical comorbidities or groups with different psychiatric disorders, also assessing moderators. Primary outcome was all-cause mortality risk ratio (RR); key secondary outcomes were mortality due to suicide and natural causes. Other secondary outcomes included any other specific-cause mortality. Publication bias, subgroup and meta-regression analyses, and quality assessment (Newcastle-Ottawa Scale) were conducted. Across 135 studies spanning from 1957 to 2021 (schizophrenia: N=4,536,447; general population controls: N=1,115,600,059; other psychiatric illness controls: N=3,827,955), all-cause mortality was increased in people with schizophrenia versus any non-schizophrenia control group (RR=2.52, 95% CI: 2.38-2.68, n=79), with the largest risk in first-episode (RR=7.43, 95% CI: 4.02-13.75, n=2) and incident (i.e., earlier-phase) schizophrenia (RR=3.52, 95% CI: 3.09-4.00, n=7) versus the general population. Specific-cause mortality was highest for suicide or injury-poisoning or undetermined non-natural cause (RR=9.76-8.42), followed by pneumonia among natural causes (RR=7.00, 95% CI: 6.79-7.23), decreasing through infectious or endocrine or respiratory or urogenital or diabetes causes (RR=3 to 4), to alcohol or gastrointestinal or renal or nervous system or cardio-cerebrovascular or all natural causes (RR=2 to 3), and liver or cerebrovascular, or breast or colon or pancreas or any cancer causes (RR=1.33 to 1.96). All-cause mortality increased slightly but significantly with median study year (beta=0.0009, 95% CI: 0.001-0.02, p=0.02). Individuals with schizophrenia <40 years of age had increased all-cause and suicide-related mortality compared to those ≥40 years old, and a higher percentage of females increased suicide-related mortality risk in incident schizophrenia samples. All-cause mortality was higher in incident than prevalent schizophrenia (RR=3.52 vs. 2.86, p=0.009). Comorbid substance use disorder increased all-cause mortality (RR=1.62, 95% CI: 1.47-1.80, n=3). Antipsychotics were protective against all-cause mortality versus no antipsychotic use (RR=0.71, 95% CI: 0.59-0.84, n=11), with largest effects for second-generation long-acting injectable anti-psychotics (SGA-LAIs) (RR=0.39, 95% CI: 0.27-0.56, n=3), clozapine (RR=0.43, 95% CI: 0.34-0.55, n=3), any LAI (RR=0.47, 95% CI: 0.39-0.58, n=2), and any SGA (RR=0.53, 95% CI: 0.44-0.63, n=4). Antipsychotics were also protective against natural cause-related mortality, yet first-generation antipsychotics (FGAs) were associated with increased mortality due to suicide and natural cause in incident schizophrenia. Higher study quality and number of variables used to adjust the analyses moderated larger natural-cause mortality risk, and more recent study year moderated larger protective effects of antipsychotics. These results indicate that the excess mortality in schizophrenia is associated with several modifiable factors. Targeting comorbid substance abuse, long-term maintenance antipsychotic treatment and appropriate/earlier use of SGA-LAIs and clozapine could reduce this mortality gap.

Factors Associated with Medication Adherence to Long-Acting Injectable Antipsychotics: Results from the STAR Network Depot Study

INTRODUCTION

Long-acting injectable (LAI) antipsychotics are prescribed to people with severe psychiatric disorders who show poor adherence to oral medication. The present paper examined factors potentially associated with medication adherence to LAI treatment.

METHODS

The STAR (Servizi Territoriali Associati per la Ricerca) Network Depot Study was a multicenter, observational, prospective study that enrolled 461 subjects initiating a LAI from 32 Italian centers. After 6 and 12 months of treatment, we evaluated differences between participants with high (≥5 points) and low (<5 points) medication adherence using Kemp's 7-point scale in sociodemographic, clinical, psychopathological, and drug-related variables. Factors that differed significantly between the two groups were entered for multivariate logistic regression.

RESULTS

Six months after enrollment, participants with high medication adherence were younger, living with other people, had lower Brief Psychiatric Rating Scale (BPRS) total scores, lower adverse events, and a more positive attitude toward medication than participants with low adherence. Multivariate regression confirmed lower BPRS resistance and activation scores, absence of adverse events, and positive attitude toward medication as factors significantly associated with good adherence. After 12 months, all BPRS subscales were significantly lower in the high adherence group, which also showed a more positive attitude toward medication. BPRS resistance and attitude toward medication were confirmed as factors associated with medication adherence.

DISCUSSION

Our findings suggest that adherence to LAI is principally related to attitude toward medication and traits of suspiciousness/hostility. Quality of patient-clinician relationship and tailored psychoeducational strategies may positively affect adherence in people undergoing psychopharmacological treatment, including LAI.

Multimodal Correlates of Cannabis Use among U.S. Veterans with Bipolar Disorder: An Integrated Study of Clinical, Cognitive, and Functional Outcomes

Objective: Cannabis use (CU) is common among persons with bipolar disorder (BD). Evidence suggests that CU is associated with poorer outcomes among persons with BD; however, these findings remain inconsistent. The present exploratory study aims to examine clinical, functional, and cognitive correlates of CU among persons with BD. Methods: U.S. veterans with BD type I who participated in a large-scale, nationwide study were categorized into four groups: current CU, past CU, past other drug use, and no drug use. Bivariate analyses, univariate analyses of covariance, and Levene's Test for Equality of Variance were used to compare groups on clinical, cognitive, and functional measures. Results: Of 254 (84.6% male) veterans with BD type I included in the analyses, 13 (5.1%) had current CU, 37 (14.5%) past CU, 77 (30.3%) past other drug use, and 127 (50%) reported no drug use. BD with CU was associated with post-traumatic stress disorder (PTSD) and experiencing lifetime suicidal ideation. Notably, current CU was associated with higher working memory performance, compared to both past CU and no drug use. Likewise, current CU was associated with higher functional capacity, compared to past CU as well as no drug use. Conclusions: These findings contribute to the growing literature on the complex effects of cannabis on BD. As the commercialization and legalization of cannabis increases, further research in this area is warranted to quantify posed risks to this population, and thereby guide clinical decision-making.

Cannabis use and medication nonadherence in bipolar disorder: A nationwide inpatient sample database analysis

BACKGROUND

Medication nonadherence among bipolar disorder (BD) is often linked with comorbid substance use disorders. This study aims to investigate cannabis use disorder (CUD) association with medication noncompliance in hospitalized BD patients.

METHODS

Using data on 266,303 BD hospitalizations between 2010 and 2014 from the US Nationwide Inpatient Sample database, we obtained medication noncompliance rates stratified by demographics and CUD. Logistic regression was used to evaluate factors associated with medication noncompliance.

RESULTS

Overall mean age, the prevalence of CUD, and medication nonadherence were 41.58 (± 0.11) years, 15.0% and 16.1%, respectively. There were 56.6% females in the overall population. There was a significant difference in the characteristics of those in the medication nonadherence vs adherence groups, including age, sex, race, comorbid substance use, income, insurance type, hospital region, and hospital teaching status (p < 0.001). After adjusting for other variables using multivariate analysis, there remained a statistically significant association of medication nonadherence in BD hospitalization and CUD (OR 1.42, 95% CI 1.36-1.48).

LIMITATION

Confounding multiple substance use could not be accounted for, and the retrospective nature of the database which includes only inpatients is prone to possible selection and reporting bias.

CONCLUSION

CUD statistically predicts increased rates of medication nonadherence among patients with BD. Given the possible association of CUD with medication nonadherence among BD patients, collaborative work between general adult psychiatry and addiction services is imperative in improving the management outcome of patients with BD and comorbid CUD.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cannabis use disorder and dissociation: A report from a prospective first-episode psychosis study

BACKGROUND

Cannabis is the most used recreational drug worldwide. Its use can increase the risk of developing psychotic disorders and exacerbate their course. However, the relationship between cannabis use and dissociative symptoms has been scarcely investigated.

AIMS

To examine differences in psychotic and dissociative symptoms, and in functioning in first-episode psychotic patients (FEPp) using cannabis compared with those not using cannabis.

METHODS

Between January 2014 and December 2019, seventy FEPp with cannabis use disorder (N = 35) and without it (N = 35) were recruited in psychiatric inpatient facilities in the Italian regions of Lazio and Piemonte. All subjects were assessed at FEP, after 4 and 8 months, using the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning (GAF) scale and the Dissociative Experiences Scale - II (DES-II). Detailed information on the pattern of cannabis and other substance use were collected.

RESULTS

FEP using cannabis showed higher levels of positive symptomatology, dissociative experiences and worse functioning than their non-user counterpart, despite a comparable antipsychotic treatment. At an eight-month prospective evaluation, FEP using cannabis still showed higher levels of positive symptomatology and dissociation. Moreover, global functioning worsened over time in FEPp using cannabis, whereas it improved those not using it.

DISCUSSION

Our findings suggest that a greater degree of dissociation and positive symptoms at FEPp and their persistence over time may characterise cannabis-associated psychosis. Both these factors might explain the overall functioning worsening over time that we observed in the cannabis-user group compared to the functioning improvement in the non-user group.

Cannabis use is associated with lower retention in methadone maintenance treatment, but not among schizophrenic- and other chronically psychotic patients

The findings of studies on cannabis use and retention in methadone maintenance treatment (MMT) are inconsistent.

To study cannabis use and its relationship to patients' outcomes in MMT with/without lifetime DSM-IV-TR schizophrenia/chronic-psychosis diagnosis.

Since June 1993, 877 patients with available lifetime DSM-IV-TR psychiatric diagnosis were followed-up until December 2017. Urine drug screens on admission and after one year were analyzed.

Lifetime schizophrenia/psychosis was diagnosed in 50 (5.7%) patients. They did not differ from the other 827 by admission cannabis use (18.0% vs. 12.3%) and had similar 1-year retention rates (76.0% vs.77.0%, respectively). Cumulative retention of the cohort excluding schizophrenia/chronic-psychosis was longer for the 667 patients who did not use cannabis after 1-year (9.1 years, 95%CI 8.4-9.9) compared with the 118 cannabis-users after 1-year (6.0 years, 95% CI 4.8-7.2, p<.001). Among the schizophrenia/chronic-psychosis group, cannabis was not related to retention (38 non-users, 7.9 years 95%CI 5.2-10.5 vs. 9 cannabis-users, 9.9 years, 95% CI 3.8-16.0, p=.5). Survival was shorter for the 41 schizophrenia/chronic-psychosis non-users (15.2 years, 95% CI 12.8-17.7) than for the 719 non-schizophrenia/chronic-psychosis non-users (18.5, 95%CI 17.9-19.2, p = 0.009). However, survival was comparable among the 9 cannabis-users with schizophrenia/chronic-psychosis (20.1, 95% CI 16.2-24.1) and 101 other cohort users (18.6, 95% CI 16.9-20.4).

Cannabis use is associated with decreased retention among MMT patients, however the effects of cannabis on schizophrenia/psychosis patients on retention and survival cannot be verified due to the small sample size and the limited data regarding chronicity of cannabis use. Future larger, prospective studies are needed.

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.

General risks of harm with cannabinoids, cannabis, and cannabis-based medicine possibly relevant to patients receiving these for pain management: an overview of systematic reviews

ABSTRACT

The growing demand for improved pain treatments together with expanding legalization of, and access to, cannabinoids, cannabis, and cannabis-based medicines has intensified the focus on risk-benefit considerations in pain management. Given limited harms data from analgesic clinical trials, we conducted an overview of systematic reviews focused on all harms possibly relevant to patients receiving cannabinoids for pain management. This PROSPERO-registered, PRISMA-compliant systematic overview identified 79 reviews, encompassing over 2200 individual reports about psychiatric and psychosocial harms, cognitive/behavioral effects, motor vehicle accidents, cardiovascular, respiratory, cancer-related, maternal/fetal, and general harms. Reviews, and their included studies, were of variable quality. Available evidence suggests variable associations between cannabis exposure (ranging from monthly to daily use based largely on self-report) and psychosis, motor vehicle accidents, respiratory problems, and other harms. Most evidence comes from settings other than that of pain management (eg, nonmedicinal and experimental) but does signal a need for caution and more robust harms evaluation in future studies. Given partial overlap between patients receiving cannabinoids for pain management and individuals using cannabinoids for other reasons, lessons from the crisis of oversupply and overuse of opioids in some parts of the world emphasize the need to broadly consider harms evidence from real-world settings. The advancement of research on cannabinoid harms will serve to guide optimal approaches to the use of cannabinoids for pain management. In the meantime, this evidence should be carefully examined when making risk-benefit considerations about the use of cannabinoids, cannabis, and cannabis-based medicine for chronic pain.

Nonadherence after hospital discharge in patients with schizophrenia or schizoaffective disorder: A six-month naturalistic follow-up study

BACKGROUND

Despite a wealth of studies seeking to identify factors associated with nonadherence few consistent predictors have been determined, and several gaps still exist in the literature.

METHOD

We assessed 110 consecutively admitted patients diagnosed with schizophrenia or schizoaffective disorder according to ICD-10 criteria. Assessments were performed during hospitalization and at six-months follow-up. Evaluation included sociodemographic, clinical, psychopathologic and treatment-related variables. Prevalence of nonadherence, associated variables, reasons for nonadherence and possible subtypes were explored. Adherence was defined as the concurrence of adherence to antipsychotic treatment and adherence to outpatient follow-up, during the six-month period.

RESULTS

Nonadherence was detected in 58.2% of patients. An identifiable profile was found in nonadherent patients. After multivariate logistic regression analysis, low socio-economic level (OR = 3.68; 95% CI = 1.42-9.53), current cannabis use or abuse (OR = 2.79; 95% CI = 1.07-7.28), nonadherence as a reason for relapse and admission (OR = 5.46; 95% CI = 2.00-14.90), and greater overall severity of symptoms at six months follow-up (OR = 2.00; 95% CI = 1.02-3.95) remained independently associated with nonadherence. Believing that medication is unnecessary was the most reported reason for nonadherence. For nonadherent patients (N = 64), two distinguishable subtypes were found: intentional nonadherence (N = 32; 50%), and unintentional nonadherence (N = 32; 50%).

CONCLUSIONS

A large percentage of patients with schizophrenia or schizoaffective disorder did not adhere to their treatment in the post-discharge follow-up period. The profile identified may enable better prevention of this problem. Specific reasons for nonadherence should also be explored to provide individualized strategies.

Dehydration in older people: A systematic review of the effects of dehydration on health outcomes, healthcare costs and cognitive performance

OBJECTIVE

To systematically examine the effect of dehydration on health outcomes, identify associated financial costs and consider impacts on cognitive performance in older adults.

DESIGN

A systematic review of English-language articles via OVID using MEDLINE, PsychINFO, EMBASE, and others, to March 2018. Included studies examined the relationship between hydration status and health, care costs or cognitive outcome.

SETTING

Cross sectional and cohort data from studies reporting on dehydration in older adults.

PARTICIPANTS

Adults aged 60 years and older.

MEASUREMENTS

Independent quality ratings were assessed for all extracted articles.

RESULTS

Of 1684 articles screened, 18 papers (N = 33,707) met inclusion criteria. Participants were recruited from hospital settings, medical long-term care centres and the community dwelling population. Data were synthesised using a narrative summary. Mortality rates were higher in dehydrated patients. Furthermore, health outcomes, including frailty, bradyarrhythmia, transient ischemic attacks, oral health and surgery recovery are linked to and worsened by dehydration. Length of hospital stay, either as a principal or secondary diagnosis, is greater in those with dehydration, compared to those who are euhydrated. Finally, neurocognitive functioning may be impacted by dehydration. There are issues with study design, inconsistency in hydration status measurement and different measures used for outcome assessment.

CONCLUSION

Dehydration in older people is associated with increased mortality, poorer course of illness and increased costs for health services. In addition, there is some, but sparse evidence that dehydration in older people is linked to poorer cognitive performance. Intervention studies should test strategies for reducing dehydration in older adults.

Individualized prediction of 2-year risk of relapse as indexed by psychiatric hospitalization following psychosis onset: Model development in two first episode samples

BACKGROUND

Although most patients with psychotic disorders experience relapse, it is not possible to predict whether or when an individual patient is going to relapse. We aimed to develop a multifactorial risk prediction algorithm for predicting risk of relapse in first episode psychosis (FEP).

METHODS

Data from two prospectively collected cohorts of FEP patients (N = 1803) were used to develop three multiple logistic prediction models to predict risk of relapse (defined as hospitalization) within the first 2 years of onset of psychosis. Model 1 (M1_S1) used data obtained from clinical notes (Sample 1) while model 2 (M2_S2) applied the same set of predictors using data obtained from research interviews (Sample 2). The final model (Sample 2: M3_S2) used the same predictors plus additional detailed information on predictors. Model performance was evaluated employing measures of overall accuracy, calibration, discrimination and internal validation.

RESULTS

In both samples, the 2-year probability of psychiatric hospitalization was 37%. Of all the models, discrimination accuracy was lowest when limited information (such as socio-demographic and clinical parameters) was included in the prediction model. Model M3_S2 using additional information (descriptors of pattern of cannabis, nicotine, alcohol and other illicit drug use) obtained from research interview had the best discrimination accuracy (Harrell's C index 0.749).

CONCLUSIONS

The measures that contributed most to predicting hospitalization are readily accessible in routine clinical practice, suggesting that a risk prediction tool based on these models would be clinically practicable following validation in independent samples and permit a personalized approach to relapse prevention in psychosis.

Cannabis Use, Cannabis Use Disorder, and Comorbid Psychiatric Illness: A Narrative Review

BACKGROUND

The landscape of attitudes, legal status and patterns of use of cannabis is rapidly changing in the United States and elsewhere. Therefore, the primary aim of this narrative review is to provide a concise overview of the literature on the comorbidity of cannabis use and cannabis use disorder (CUD) with other substance use and psychiatric disorders, and to use this information to accurately guide future directions for the field.

METHODS

A literature review of PubMed was conducted for studies relating to cannabis use, CUD, and a co-occurring psychiatric disorder. To provide an overview of representative data, the literature review focused on national-level, population-based work from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and National Survey on Drug Use and Health (NSDUH) surveys. Considering rapidly changing cannabis laws, recent (past five-year) studies were addressed.

RESULTS

A strong body of literature shows associations between cannabis use and CUD with other drug use, psychosis, mood disorders, anxiety disorders, and personality disorders. The strongest evidence of a potential causal relationship exists between cannabis use and psychotic disorders. While some evidence shows potential directionality between cannabis use and mood and anxiety disorders, results are inconsistent. Studies have established higher rates of CUD among those with personality disorders, but little about the specifics of this relationship is understood.

CONCLUSIONS

Although the general population in the United States increasingly perceives cannabis to be a harmless substance, empirical evidence shows that cannabis use is associated both with CUD and comorbid psychiatric illness. However, there is mixed evidence regarding the role of cannabis in the etiology, course, and prognosis of a co-occurring disorder across all categories of psychiatric disorders. Future research should expand on the existing body of literature with representative, longitudinal data, in order to better understand the acute and long-term effects of cannabis on comorbid psychiatric illness.

Rate and predictors of interrupted patient follow-up after first-episode psychosis - a retrospective cohort study in France

BACKGROUND

Patient adherence to follow-up after a first episode of psychosis (FEP) is currently a major challenge. Patient's early adherence reduces the risk of relapse and improves their prognosis in the short and long term. The primary goal of our study was to determine the incidence of treatment disengagement at 1-year follow-up in patients with first-episode schizophrenia, schizophreniform or schizoaffective disorder. The secondary goal was to assess the factors associated with treatment disengagement in this patient population.

METHODS

We conducted a monocentric retrospective study of 136 patients in France. Relevant information was collected on sociodemographic, pre-morbidities and co-morbidities data, as well as the management and treatment characteristics at 1.3 and 12 months. Survival analysis was used to assess the association between clinical variables, management and treatment disengagement.

RESULTS

Eighty-four patients (62%) have interrupted their medical follow-up at 1 year, 16% at 1 month and 34% at 3 months. A higher number of out-patient appointments after a FEP was associated with better adherence (HR:0.85 p < .0001 95% IC = [0.0-0.9]). Initial management seems to play an important role. Involuntary admissions (HR:7.14 p = .015 95% IC = [1.48-34.52]) and total number of admissions (HR:6.86 p < .0001 95% IC = [2.47-19.05]) predict disengagement at 1 month while an increased number of out-patient appointments at 3 months predicts adherence (HR:0.60 p < .0001 95% IC = [0.00-0.74]). Being a single parent is associated with disengagement at 3 months (HR:15.51 p = .022 95% IC = [1.49-161.65]).

CONCLUSIONS

Incidence of disengagement is high. It might be necessary to change our management in order to develop out-patient or day-admission care and intensify care for patients at risk.

Antipsychotic Treatment Failure: A Systematic Review on Risk Factors and Interventions for Treatment Adherence in Psychosis

Objective: Antipsychotic medication non-adherence has detrimental effects on patients' clinical outcome. It is unclear which risk factors affect adherence most and which interventions are effective at improving adherence to antipsychotic medication. The aim of this systematic review is to summarize evidence exploring risk factors of non-adherence to antipsychotic treatment and effectiveness of intervention to improve adherence in patients with psychotic spectrum disorders.

Methods: We conducted a systematic search in PubMed from 1994 to 2019 using a structured search strategy. Studies were quality assessed, and studies reporting on possible risk factors and intervention strategies were synthesized.

Results: We reviewed 26 studies on factors related to antipsychotic medication adherence and 17 studies on interventions to improve adherence in patients with psychosis spectrum disorders. Risk factors of non-adherence included younger age, poor illness insight, cannabis abuse, and the presence of severe positive symptoms. Antipsychotic medication adherence was associated with positive attitude toward medication of both patients and their family, family involvement, and illness insight. Somewhat consistent evidence was found for interventions involving family and technology-based interventions and strategies combining depot medication with psychoeducation. However, given the wide range of heterogeneous interventions and methodological limitations, findings must be interpreted with caution.

Conclusion: Despite much effort invested in the research area of antipsychotic medication adherence, the heterogeneity in study design and outcome, adding to confounding effects and possible biases, and methodological restraints complicate comparability of the results. Future research in this field should therefore be conducted on patient-tailored interventions, considering risk factors affecting the patient and implementing well-validated, standardized assessment methods. Accordingly, this systematic review seeks to facilitate endeavors improving adherence to antipsychotic treatment by identifying modifiable and non-modifiable risk factors, outlining effective intervention strategies, and proposing recommendations to enhance adherence strategies.

Do cannabis use disorders increase medication non-compliance in schizophrenia?: United States Nationwide inpatient cross-sectional study

OBJECTIVES

This study aims to find the prevalence of medication non-compliance among schizophrenia inpatients and to compare the relative risks of medication non-compliance with cannabis use disorders (CUDs) versus without CUDs. In addition, this study also examines the odds of medication non-compliance in schizophrenia inpatients with CUDs.

METHODS

This is a retrospective cross-sectional analysis of the nationwide inpatient sample. This sample includes 1,030,949 inpatients (age 18 to 65 years) from 2010 to 2014 with primary ICD-9 diagnoses of schizophrenia and other psychotic disorders, that were further sub grouped based on medication non-compliance. CUDs were recognized using the ICD-9 codes.

RESULTS

The prevalence of medication non-compliance was 26% among schizophrenia inpatients. Multivariable analysis revealed that CUD comorbidity was a significant risk factor for medication non-compliance among schizophrenia patients when unadjusted (OR 1.49, 95%CI 1.469-1.503), and association remained significant even after adjusting for covariates (adjusted OR 1.38, 95%CI 1.268-1.489). Comorbid CUD was seen in young adults (18-35 years, 62.4%), males (80.5%), African Americans (54.1%) and low-income families below 25th percentile (48.6%) with personality disorders (10.5%).

CONCLUSION

Medication compliance is a challenge among schizophrenia patients, which has a significant adverse impact on the course of illness. CUD Comorbidity increases the risk of medication non-compliance significantly among schizophrenia patients. In addition to case management, an integrated treatment model to address both substance use disorders and psychosis will translate into better long-term outcomes in schizophrenia patients.

Assessment of coexisting psychosis and substance misuse: complexities, challenges and causality

Substance misuse worsens the prognosis for people suffering psychosis and places them at risk of being denied appropriate mental health service interventions. To increase the chances of its success, the plan of management for patients with coexisting psychosis and substance misuse should be based on a valid formulation of their problems, which in turn is dependent on the clinician having (a) a thorough understanding of the bidirectional and changing ways that substance use and mental illness symptoms can interact, (b) an awareness of their own biased implicit assumptions about causality in explaining these interactions and (c) a framework for assessment and formulation. This article addresses these three areas with reference to the evidence base and to clinical experience in a way that guides mental health clinicians in the assessment of patients with coexisting psychosis and substance misuse.

Once-Monthly Long-Acting Injectable Aripiprazole for the Treatment of Patients with Schizophrenia and Co-occurring Substance Use Disorders: A Multicentre, Observational Study

AIM

To evaluate the efficacy and impact of long-acting injectable (LAI) aripiprazole in patients with schizophrenia with a coexisting substance use disorder (SUD).

PATIENTS AND METHODS

A multicenter, observational, descriptive and retrospective study was conducted in patients with a DSM-5 diagnosis of schizophrenia who had a coexisting SUD and were treated with LAI-aripiprazole. Disease severity was evaluated with the Clinical Global Impression (CGI) severity scale for schizophrenia, daily functioning and disability were evaluated with the World Health Organisation Disability Assessment Scale (WHODAS-2.0), and the severity of the addiction was evaluated with the Severity of Dependence Scale (SDS).

RESULTS

The sample included 40 patients. Overall, after 6 months of treatment with LAI-aripiprazole at a dose of 400 mg/4 weeks in 77.5% of the patients, we observed significant improvement in the psychopathological symptoms, with a reduction of over 30% in the scores of the five CGI-severity scales. The WHODAS-2.0 mean (standard deviation) score was also significantly reduced from 57.6 (8.2) to 42.3 (4.3) points (p < 0.001). Regarding SUDs, after 6 months of treatment, substance use was stopped in 5 of the 9 patients with cocaine use disorder and in 3 of the 16 patients with alcohol abuse disorder. A significant reduction in the severity of the dependence was observed only in the subgroups of participants with cocaine and alcohol use disorders.

CONCLUSION

Our study suggests that once-monthly LAI-aripiprazole retains its antipsychotic efficacy in patients with schizophrenia and a coexisting SUD and could be useful for the management of cocaine or alcohol use disorders in this population.

Antipsychotic treatment failure in patients with psychosis and co-morbid cannabis use: A systematic review

Whilst the effects of cannabis preceding psychosis onset are well established, an effect post-onset is less clear. Emerging evidence suggests that cannabis use is associated with increased relapse outcomes possibly because of determinants, antipsychotic treatment failure and medication adherence, that are not mutually exclusive. Due to the paucity of literature on antipsychotic treatment failure an association with cannabis remains conjectural. This review sought to summarise current evidence regarding the effect of cannabis use on antipsychotic treatment failure among users and non-users with psychosis. Ovid databases (Embase, Journals@Ovid Full Text, OvidMEDLINE® In-Process and Other Non-Indexed Citations and PsycINFO) were searched to identify relevant articles. Seven articles met eligibility criteria. Cannabis use was associated with the following deleterious outcomes increased: odds of non-remission, prescription of unique antipsychotic medications, cumulative prescription of Clozapine and poor treatment trajectories. One study reported similar life-time, but lower past-year, rates of cannabis use in those prescribed Clozapine. Another study reported differences between groups for chlorpromazine equivalent doses for long-term Olanzapine prescription. Improved methodologies are warranted due to a lack of well-designed prospective studies and heterogeneity of key variables. There remains, despite research paucity, the need to encourage early cannabis cessation and higher-quality research to inform clinical practice.

The Potential of Cannabidiol as a Treatment for Psychosis and Addiction: Who Benefits Most? A Systematic Review

The endogenous cannabinoid (eCB) system plays an important role in the pathophysiology of both psychotic disorders and substance use disorders (SUDs). The non-psychoactive cannabinoid compound, cannabidiol (CBD) is a highly promising tool in the treatment of both disorders. Here we review human clinical studies that investigated the efficacy of CBD treatment for schizophrenia, substance use disorders, and their comorbidity. In particular, we examined possible profiles of patients who may benefit the most from CBD treatment. CBD, either as monotherapy or added to regular antipsychotic medication, improved symptoms in patients with schizophrenia, with particularly promising effects in the early stages of illness. A potential biomarker is the level of anandamide in blood. CBD and THC mixtures showed positive effects in reducing short-term withdrawal and craving in cannabis use disorders. Studies on schizophrenia and comorbid substance use are lacking. Future studies should focus on the effects of CBD on psychotic disorders in different stages of illness, together with the effects on comorbid substance use. These studies should use standardized measures to assess cannabis use. In addition, future efforts should be taken to study the relationship between the eCB system, GABA/glutamate, and the immune system to reveal the underlying neurobiology of the effects of CBD.

Longitudinal assessment of the effect of cannabis use on hospital readmission rates in early psychosis: A 6-year follow-up in an inpatient cohort

Cannabis is the most commonly used illicit drug in psychosis patients and has been identified as a risk factor for relapse and subsequent hospital readmission, having substantial economic implications. To clarify the contribution of cannabis consumption to hospital readmission, a consecutive inpatient cohort of 161 early psychosis patients was included into the study. Data on cannabis use at admission and number of hospital readmissions and length of stay (LOS, number of inpatient days) in a 6-year follow-up was extracted from clinical notes. 62.4% of the patients had lifetime cannabis use. Their admission lasted on average 54.3 ± 75 days and over the following 6 years patients had 2.2 ± 2.8 hospital readmissions, for a total of 197.4 ± 331.5 days. Cannabis use significantly predicted the number of hospital readmissions and LOS in the following 6 years, the latter remaining significant after adjusting for use of other substance. Cannabis-using patients of male gender and Black ethnicity had a longer LOS at follow-up compared to female patients and other ethnic groups, respectively. Having a history of cannabis use when admitted to an early intervention inpatient unit for psychosis is associated with a higher number of subsequent hospital readmissions and a longer LOS, especially in male and Black patients.

Risperidone Provides Better Improvement of Sleep Disturbances Than Haloperidol Therapy in Schizophrenia Patients With Cannabis-Positive Urinalysis

A high percentage of persons with Schizophrenia also uses Cannabis and this may potentially alter the therapeutic benefits of the antipsychotic medications prescribed. The aim of this study was to assess the impact of Cannabis usage on antipsychotic therapy of sleep disturbances in schizophrenia subjects. Male subjects, ≥18 years, admitted to the University Hospital of the West Indies psychiatric ward between October 2015 and October 2016, and diagnosed with schizophrenia were recruited for the study. Following written informed consent to the study, subjects were prescribed either risperidone monotherapy or haloperidol monotherapy orally for 14 days and classified as Cannabis users (CU) or non-users (non-CU), with presence/absence of Cannabis metabolite in urine samples. After 1 week of admission, subjects wore the Actiwatch-2 device, to record sleep data for 7 consecutive nights. Inferential statistical analysis involved non-parametric tests, expressed as median and inter-quartile ranges (IQR), with p<0.05 considered statistically significant. Fifty subjects were assessed, with a median (IQR) age of 28 (14) years. Majority (30; 60%) were CU, displaying longer sleep latency (SL) than non-CU when receiving haloperidol; but equivalent SL when receiving risperidone. In comparison to non-CU, the CU also displayed longer time in bed, but shorter durations asleep, awoke more frequently during the nights and for longer durations, whether receiving haloperidol or risperidone. This resulted in lower sleep efficiency for the CU (<85%) compared to the non-CU (≥85%). Over the study period, sleep efficiency was significantly improved for non-CU receiving either risperidone (p = 0.032) or haloperidol (p = 0.010); but was only significantly improved with risperidone for the CU (p = 0.045). It is apparent that the presence of Cannabis may be impacting the therapeutic benefits of antipsychotic drugs on sleep. In schizophrenia subjects with concomitant Cannabis use, risperidone is more beneficial than haloperidol in improving sleep efficiency.

Are cannabis-using and non-using patients different groups? Towards understanding the neurobiology of cannabis use in psychotic disorders

A substantial body of credible evidence has accumulated that suggest that cannabis use is an important potentially preventable risk factor for the development of psychotic illness and its worse prognosis following the onset of psychosis. Here we summarize the relevant evidence to argue that the time has come to investigate the neurobiological effects of cannabis in patients with psychotic disorders. In the first section we summarize evidence from longitudinal studies that controlled for a range of potential confounders of the association of cannabis use with increased risk of developing psychotic disorders, increased risk of hospitalization, frequent and longer hospital stays, and failure of treatment with medications for psychosis in those with established illness. Although some evidence has emerged that cannabis-using and non-using patients with psychotic disorders may have distinct patterns of neurocognitive and neurodevelopmental impairments, the biological underpinnings of the effects of cannabis remain to be fully elucidated. In the second and third sections we undertake a systematic review of 70 studies, including over 3000 patients with psychotic disorders or at increased risk of psychotic disorder, in order to delineate potential neurobiological and neurochemical mechanisms that may underlie the effects of cannabis in psychotic disorders and suggest avenues for future research.

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

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

Effect of continued cannabis use on medication adherence in the first two years following onset of psychosis

Uncertainty exists whether the use of non-prescription psychoactive substances following onset of a first episode of psychosis (FEP), in particular cannabis use, affects medication adherence. Data from FEP patients (N=233) obtained through prospective assessments measured medication adherence and pattern of cannabis and other substance use in the first two years following onset of psychosis. Multiple logistic regression analyses were employed to compare the different substance use groups with regard to risk of medication non-adherence, while controlling for confounders. The proportion of non-adherent patients was higher in those who continued using high-potency forms of cannabis (skunk-like) following the onset (83%) when compared to never regular users (51%), corresponding to an Odds Ratio (OR) of 5.26[95% Confidence Interval (CI) 1.91-15.68]. No significant increases in risk were present in those who used cannabis more sporadically or used milder forms of cannabis (hash-like). Other substances did not make an independent contribution in this model, including cigarette use ([OR 0.88, 95% CI 0.41-1.89]), alcohol use ([OR 0.66, 95% CI 0.27-1.64]) or regular use of other illicit drugs ([OR 1.03, 95% CI 0.34-3.15]) following the onset. These results suggest that continued use of high-potency cannabis following the onset of psychosis may adversely affect medication adherence.

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.