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

Cognitive behavioural therapy added to standard care for first-episode and recent-onset psychosis

BACKGROUND

Cognitive behavioural therapy (CBT) can be effective in the general population of people with schizophrenia. It is still unclear whether CBT can be effectively used in the population of people with a first-episode or recent-onset psychosis.

OBJECTIVES

To assess the effects of adding cognitive behavioural therapy to standard care for people with a first-episode or recent-onset psychosis.

SEARCH METHODS

We conducted a systematic search on 6 March 2022 in the Cochrane Schizophrenia Group's Study-Based Register of Trials, which is based on CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, PubMed, ClinicalTrials.gov, ISRCTN, and WHO ICTRP.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing CBT added to standard care vs standard care in first-episode or recent-onset psychosis, in patients of any age.

DATA COLLECTION AND ANALYSIS

Two review authors (amongst SFM, CC, LK and IB) independently screened references for inclusion, extracted data from eligible studies and assessed the risk of bias using RoB2. Study authors were contacted for missing data and additional information. Our primary outcome was general mental state measured on a validated rating scale. Secondary outcomes included other specific measures of mental state, global state, relapse, admission to hospital, functioning, leaving the study early, cognition, quality of life, satisfaction with care, self-injurious or aggressive behaviour, adverse events, and mortality.

MAIN RESULTS

We included 28 studies, of which 26 provided data on 2407 participants (average age 24 years). The mean sample size in the included studies was 92 participants (ranging from 19 to 444) and duration ranged between 26 and 52 weeks. When looking at the results at combined time points (mainly up to one year after start of the intervention), CBT added to standard care was associated with a greater reduction in overall symptoms of schizophrenia (standardised mean difference (SMD) -0.27, 95% confidence interval (CI) -0.47 to -0.08, 20 RCTs, n = 1508, I2 = 68%, substantial heterogeneity, low certainty of the evidence), and also with a greater reduction in positive (SMD -0.22, 95% CI -0.38 to -0.06, 22 RCTs, n = 1565, I² = 52%, moderate heterogeneity), negative (SMD -0.20, 95% CI -0.30 to -0.11, 22 RCTs, n = 1651, I² = 0%) and depressive symptoms (SMD -0.13, 95% CI -0.24 to -0.01, 18 RCTs, n = 1182, I² = 0%) than control. CBT added to standard care was also associated with a greater improvement in the global state (SMD -0.34, 95% CI -0.67 to -0.01, 4 RCTs, n = 329, I² = 47%, moderate heterogeneity) and in functioning (SMD -0.23, 95% CI -0.42 to -0.05, 18 RCTs, n = 1241, I² = 53%, moderate heterogeneity, moderate certainty of the evidence) than control. We did not find a difference between CBT added to standard care and control in terms of number of participants with relapse (relative risk (RR) 0.82, 95% CI 0.57 to 1.18, 7 RCTs, n = 693, I² = 48%, low certainty of the evidence), leaving the study early for any reason (RR 0.87, 95% CI 0.72 to 1.05, 25 RCTs, n = 2242, I² = 12%, moderate certainty of the evidence), adverse events (RR 1.29, 95% CI 0.85 to 1.97, 1 RCT, n = 43, very low certainty of the evidence) and the other investigated outcomes.

AUTHORS' CONCLUSIONS

This review synthesised the latest evidence on CBT added to standard care for people with a first-episode or recent-onset psychosis. The evidence identified by this review suggests that people with a first-episode or recent-onset psychosis may benefit from CBT additionally to standard care for multiple outcomes (overall, positive, negative and depressive symptoms of schizophrenia, global state and functioning). Future studies should better define this population, for which often heterogeneous definitions are used.

Terminology and assessment tools of psychosis: A systematic narrative review

AIM

Phenomena within the psychosis continuum that varies in frequency/duration/intensity have been increasingly identified. Different terms describe these phenomena, however there is no standardization within the terminology. This review evaluated the definitions and assessment tools of seven terms - (i) 'psychotic experiences'; (ii) 'psychotic-like experiences'; (iii) 'psychotic-like symptoms'; (iv) 'attenuated psychotic symptoms'; (v) 'prodromal psychotic symptoms'; (vi) 'psychotic symptomatology'; and (vii) 'psychotic symptoms'.

METHODS

EMBASE, MEDLINE, and CINAHL were searched during February-March 2019. Inclusion criteria included 1989-2019, full text, human, and English. Papers with no explicit definition or assessment tool, duplicates, conference abstracts, systematic reviews, meta-analyses, or no access were excluded.

RESULTS

A total of 2238 papers were identified and of these, 627 were included. Definitions and assessment tools varied, but some trends were found. Psychotic experiences and psychotic-like experiences were transient and mild, found in the general population and those at-risk. Psychotic-like symptoms were subthreshold and among at-risk populations and non-psychotic mental disorders. Attenuated psychotic symptoms were subthreshold but associated with distress, risk, and help-seeking. Prodromal psychotic symptoms referred to the prodrome of psychotic disorders. Psychotic symptomatology included delusions and hallucinations within psychotic disorders. Psychotic symptoms was the broadest term, encompassing a range of populations but most commonly involving hallucinations, delusions, thought disorder, and disorganization.

DISCUSSION

A model for conceptualizing the required terms is proposed and future directions needed to advance this field of research are discussed.

Psychosocial interventions for people with both severe mental illness and substance misuse

BACKGROUND

Even low levels of substance misuse by people with a severe mental illness can have detrimental effects.

OBJECTIVES

To assess the effects of psychosocial interventions for reduction in substance use in people with a serious mental illness compared with standard care.

SEARCH METHODS

The Information Specialist of the Cochrane Schizophrenia Group (CSG) searched the CSG Trials Register (2 May 2018), which is based on regular searches of major medical and scientific databases.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing psychosocial interventions for substance misuse with standard care in people with serious mental illness.

DATA COLLECTION AND ANALYSIS

Review authors independently selected studies, extracted data and appraised study quality. For binary outcomes, we calculated standard estimates of risk ratio (RR) and their 95% confidence intervals (CIs) on an intention-to-treat basis. For continuous outcomes, we calculated the mean difference (MD) between groups. Where meta-analyses were possible, we pooled data using a random-effects model. Using the GRADE approach, we identified seven patient-centred outcomes and assessed the quality of evidence for these within each comparison.

MAIN RESULTS

Our review now includes 41 trials with a total of 4024 participants. We have identified nine comparisons within the included trials and present a summary of our main findings for seven of these below. We were unable to summarise many findings due to skewed data or because trials did not measure the outcome of interest. In general, evidence was rated as low- or very-low quality due to high or unclear risks of bias because of poor trial methods, or inadequately reported methods, and imprecision due to small sample sizes, low event rates and wide confidence intervals. 1. Integrated models of care versus standard care (36 months) No clear differences were found between treatment groups for loss to treatment (RR 1.09, 95% CI 0.82 to 1.45; participants = 603; studies = 3; low-quality evidence), death (RR 1.18, 95% CI 0.39 to 3.57; participants = 421; studies = 2; low-quality evidence), alcohol use (RR 1.15, 95% CI 0.84 to 1.56; participants = 143; studies = 1; low-quality evidence), substance use (drug) (RR 0.89, 95% CI 0.63 to 1.25; participants = 85; studies = 1; low-quality evidence), global assessment of functioning (GAF) scores (MD 0.40, 95% CI -2.47 to 3.27; participants = 170; studies = 1; low-quality evidence), or general life satisfaction (QOLI) scores (MD 0.10, 95% CI -0.18 to 0.38; participants = 373; studies = 2; moderate-quality evidence). 2. Non-integrated models of care versus standard care There was no clear difference between treatment groups for numbers lost to treatment at 12 months (RR 1.21, 95% CI 0.73 to 1.99; participants = 134; studies = 3; very low-quality evidence). 3. Cognitive behavioural therapy (CBT) versus standard care There was no clear difference between treatment groups for numbers lost to treatment at three months (RR 1.12, 95% CI 0.44 to 2.86; participants = 152; studies = 2; low-quality evidence), cannabis use at six months (RR 1.30, 95% CI 0.79 to 2.15; participants = 47; studies = 1; very low-quality evidence) or mental state insight (IS) scores by three months (MD 0.52, 95% CI -0.78 to 1.82; participants = 105; studies = 1; low-quality evidence). 4. Contingency management versus standard care We found no clear differences between treatment groups for numbers lost to treatment at three months (RR 1.55, 95% CI 1.13 to 2.11; participants = 255; studies = 2; moderate-quality evidence), number of stimulant positive urine tests at six months (RR 0.83, 95% CI 0.65 to 1.06; participants = 176; studies = 1) or hospitalisations (RR 0.21, 95% CI 0.05 to 0.93; participants = 176; studies = 1); both low-quality evidence. 5. Motivational interviewing (MI) versus standard care We found no clear differences between treatment groups for numbers lost to treatment at six months (RR 1.71, 95% CI 0.63 to 4.64; participants = 62; studies = 1). A clear difference, favouring MI, was observed for abstaining from alcohol (RR 0.36, 95% CI 0.17 to 0.75; participants = 28; studies = 1) but not other substances (MD -0.07, 95% CI -0.56 to 0.42; participants = 89; studies = 1), and no differences were observed in mental state general severity (SCL-90-R) scores (MD -0.19, 95% CI -0.59 to 0.21; participants = 30; studies = 1). All very low-quality evidence. 6. Skills training versus standard care At 12 months, there were no clear differences between treatment groups for numbers lost to treatment (RR 1.42, 95% CI 0.20 to 10.10; participants = 122; studies = 3) or death (RR 0.15, 95% CI 0.02 to 1.42; participants = 121; studies = 1). Very low-quality, and low-quality evidence, respectively. 7. CBT + MI versus standard care At 12 months, there was no clear difference between treatment groups for numbers lost to treatment (RR 0.99, 95% CI 0.62 to 1.59; participants = 327; studies = 1; low-quality evidence), number of deaths (RR 0.60, 95% CI 0.20 to 1.76; participants = 603; studies = 4; low-quality evidence), relapse (RR 0.50, 95% CI 0.24 to 1.04; participants = 36; studies = 1; very low-quality evidence), or GAF scores (MD 1.24, 95% CI -1.86 to 4.34; participants = 445; studies = 4; very low-quality evidence). There was also no clear difference in reduction of drug use by six months (MD 0.19, 95% CI -0.22 to 0.60; participants = 119; studies = 1; low-quality evidence).

AUTHORS' CONCLUSIONS

We included 41 RCTs but were unable to use much data for analyses. There is currently no high-quality evidence to support any one psychosocial treatment over standard care for important outcomes such as remaining in treatment, reduction in substance use or improving mental or global state in people with serious mental illnesses and substance misuse. Furthermore, methodological difficulties exist which hinder pooling and interpreting results. Further high-quality trials are required which address these concerns and improve the evidence in this important area.

Stopping cannabis use benefits outcome in psychosis: findings from 10-year follow-up study in the PAFIP-cohort

OBJECTIVE

To examine the long-term (up to 10 years) patterns related to cannabis use in a sample of patients with first episode of psychosis (FEP) and the effect that consumption might have on clinical, functioning, and neurocognition at long-term.

METHODS

Cannabis use was described in 209 FEP patients. Patients were divided into three groups according to cannabis use: persistent users, ex-users, and never-users. Groups were longitudinally (baseline and 10-year follow-up) compared on clinical, functional, and cognitive variables.

RESULTS

Clinical differences at 10-year follow-up were observed between persistent cannabis users and the other two groups (ex-users and never-users), showing persistent users more severe symptoms (BPRS: x²  = 15.583, P ≤ 0.001; SAPS: x²  = 12.386, P = 0.002) and poorer functionality (DAS: x²  = 6.067, P = 0.048; GAF: x²  = 6.635, P = 0.033). Patients who stopped cannabis use prior to the reassessment showed a similar pattern to those who had never consumed.

CONCLUSION

The use of cannabis could negatively affect the evolution of the psychotic disorder. Perhaps the negative effects caused by cannabis use could be reversed with the cessation of consumption. It is necessary to make an effort in the intervention toward an early withdrawal from the use of cannabis, since this could play an important role in the prognosis of the disease.