Cannabis and first-episode psychosis: different long-term outcomes depending on continued or discontinued use

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

OBJECTIVE

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

DESIGN AND SETTING

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

DESIGN

Observational study with exploratory mediation analysis.

SETTING

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

PARTICIPANTS

2026 people presenting to early intervention services with FEP.

EXPOSURE

Cannabis use at presentation, identified using natural language processing.

MAIN OUTCOME MEASURES

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

MEDIATOR

Number of unique antipsychotics prescribed.

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

RESULTS

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

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

UK National Institute of Health Research.

Course of cannabis use and clinical outcome in patients with non-affective psychosis: a 3-year follow-up study

BACKGROUND

Prospective studies on the relationship between course of cannabis use and clinical outcome in patients with non-affective psychotic disorders are inconclusive. The current study examined whether (1) persistent, recently started, discontinued and non-cannabis-using patients with a psychotic disorder differed with regard to illness outcome at 3-year follow-up, and (2) whether timing of cannabis discontinuation was associated with course of clinical outcome.

METHOD

This 3-year follow-up study was part of a multi-center study in the Netherlands and Belgium (Genetic Risk and Outcome of Psychosis; GROUP). We used mixed-model analyses to investigate the association between pattern of cannabis use and symptoms, global functioning and psychotic relapse.

RESULTS

In our sample of 678 patients, we found persistent users to have more positive and general symptoms, worse global functioning and more psychotic relapses compared with non-users and discontinued users [Positive and Negative Syndrome Scale (PANSS) positive, p < 0.001; PANSS general, p < 0.001; Global Assessment of Functioning (GAF) symptoms, p = 0.017; GAF disability, p < 0.001; relapses, p = 0.038]. Patients who started using cannabis after study onset were characterized by worse functioning at baseline and showed an increase in general symptoms (including depression and anxiety) at the 3-year follow-up (p = 0.005). Timing of cannabis discontinuation was not associated with clinical outcome.

CONCLUSIONS

These findings suggest that cannabis use in patients with a psychotic disorder has a long-lasting negative effect on illness outcome, particularly when persistent. Treatment should focus on discouraging cannabis use.

Brain volume in male patients with recent onset schizophrenia with and without cannabis use disorders

BACKGROUND

Schizophrenia is highly comorbid with cannabis use disorders (CUDs), and this comorbidity is associated with an unfavourable course. Early onset or frequent cannabis use may influence brain structure. A key question is whether comorbid CUDs modulate brain morphology alterations associated with schizophrenia.

METHODS

We used surface-based analysis to measure the brain volume, cortical thickness and cortical surface area of a priori-defined brain regions (hippocampus, amygdala, thalamus, caudate, putamen, orbitofrontal cortex, anterior cingulate cortex, insula, parahippocampus and fusiform gyrus) in male patients with schizophrenia or related disorders with and without comorbid CUDs and matched healthy controls. Associations between age at onset and frequency of cannabis use with regional grey matter volume were explored.

RESULTS

We included 113 patients with (CUD, n = 80) and without (NCUD, n = 33) CUDs and 84 controls in our study. As expected, patients with schizophrenia (with or without a CUD) had smaller volumes of most brain regions (amygdala, putamen, insula, parahippocampus and fusiform gyrus) than healthy controls, and differences in cortical volume were mainly driven by cortical thinning. Compared with the NCUD group, the CUD group had a larger volume of the putamen, possibly driven by polysubstance use. No associations between age at onset and frequency of use with regional grey matter volumes were found.

LIMITATIONS

We were unable to correct for possible confounding effects of smoking or antipsychotic medication.

CONCLUSION

Patients with psychotic disorders and comorbid CUDs have larger putamen volumes than those without CUDs. Future studies should elaborate whether a large putamen represents a risk factor for the development of CUDs or whether (poly)substance use causes changes in putamen volume.

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

Background

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

Methods

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

Results

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

Conclusions

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

Social functioning trajectories of young first-episode psychosis patients with and without cannabis misuse: a 30-month follow-up study

The aim of the study was to investigate trajectories of social functioning in young people with first-episode psychosis (FEP) with and without cannabis misuse using a secondary analysis of data from the Episode-II trial. Forty-two young people with FEP and comorbid cannabis use disorder were compared with 39 young people with FEP but without a cannabis use disorder. Social functioning was assessed every 6 months during a 30-month follow-up. Multilevel linear growth curve modeling was used to compare the social functioning trajectories over time for those with and without cannabis misuse. Cannabis misuse was not associated with social functioning at baseline assessment. Over a 30-month follow-up, FEP patients without cannabis disorder showed significant improvements in their social functioning, whereas patients with cannabis misuse at baseline displayed no such improvement. Patients with and without cannabis misuse differed significantly in their levels of social functioning after 24 months. Similar results were obtained after adjusting for potential confounders (i.e., age, gender, negative symptoms, premorbid functioning, DSM-IV diagnoses, baseline social functioning and other substance use). In the context of a specialized early intervention service, patients with cannabis misuse at baseline did not attain the improvements in social outcomes observed in their counterparts without cannabis misuse. There is a need to develop effective interventions to reduce cannabis misuse to ultimately improve social outcomes in young people with psychosis.

The HELPER programme: HEalthy Living and Prevention of Early Relapse – three exploratory randomised controlled trials of phase-specific interventions in first-episode psychosis

Background

Schizophrenia represents a substantial cost to the NHS and society because it is common (lifetime prevalence around 0.5–1%); it begins in adolescence or early adulthood and often causes lifelong impairment. The first 3 years are a ‘critical period’ in which the course of the illness is determined. Hence under the NHS Plan, specialist early intervention in psychosis services were established to care for people who develop psychosis between the ages of 14 and 35 years for the first 3 years of their illness. However, there has been a lack of evidence-based treatments specifically designed for the early years. This is important because emerging evidence has shown that in the critical period it is vital to avoid relapse and prevent deterioration in physical health, as both can drastically reduce the chances of a full recovery.

Objectives

To develop and evaluate three phase-specific interventions to prevent relapse and/or deterioration in physical health in people with first-episode psychosis. The interventions were (1) cognitive remediation (CR) to improve meta-cognition and insight and enhance engagement in cognitive therapy [evaluated in the IMproving PArticipation in Cognitive Therapy (IMPACT) trial]; (2) a healthy-living intervention to control weight in people taking antipsychotic medication after a first episode of psychosis [evaluated in the INTERvention to Encourage ACTivity, Improve Diet, and Reduce Weight Gain (InterACT trial)]; and (3) integrated motivational interviewing and cognitive–behavioural therapy (MiCBT) to reduce cannabis use [evaluated in the Rethinking Choices After Psychosis (ReCAP) trial]. The trials were conducted to explore the case for larger definitive trials with relapse as a primary outcome measure. However, as small trials do not have sufficient power to detect significant reductions in relapse, each was focused on a relevant primary outcome for which there was sufficient power to detect a significant difference. In all three trials relapse was a secondary outcome in the hope of detecting trends towards lower relapse rates in the presence of effective interventions or a general trend across all three studies towards lower relapse rates.

Design

Three exploratory randomised controlled trials (RCTs) accompanied by qualitative work employing grounded theory and framework analysis to inform the interventions and determine acceptability (InterACT and ReCAP trials).

Setting

Five early-intervention services in the north-west of England.

Participants

Early-intervention service users aged 16–35 years who had recently experienced a first episode of psychosis. Participants in the IMPACT trial were drawn from a waiting list of people referred for routine CBT; those in the InterACT trial were required to have a body mass index (BMI) of ≥ 25 kg/m2(or ≥ 24 kg/m2for service users from the South Asian community); and those in the ReCAP trial metDiagnostic and Statistical Manual of Mental Disorders– Fourth Edition (DSM-IV) criteria for cannabis abuse or dependence.

Interventions

The IMPACT trial involved 13 sessions of CR over 12 weeks; the InterACT trial involved eight face-to-face sessions plus optional group activities over 12 months; and the ReCAP trial involved MiCBT in brief (12 sessions over 4.5 months) and long (24 sessions over 9 months) forms.

Main outcome measures

The primary outcome in the IMPACT trial was psychotic symptoms assessed by the Psychotic Symptom Rating Scales (PSYRATS). BMI was the primary outcome in the InterACT trial and cannabis use (measured by timeline follow-back) was the primary outcome in the ReCAP trial. Relapse was a secondary outcome across all three trials.

Results

In the IMPACT trial there was no beneficial effect of CR on psychotic symptoms; however, the amount of CBT required was significantly less after CR. In the InterACT trial a small reduction in BMI in the intervention group was not statistically significant. For participants taking olanzapine or clozapine the effect size was larger although not significant. Outcome data from the ReCAP trial are not yet available. Retention in all three trials was good, indicating that the interventions were acceptable.

Conclusions

Early-intervention services provided a good setting to conduct trials. The IMPACT trial found that CR delivered by relatively unskilled workers improved the efficiency of subsequent CBT. Across the three trials there was little evidence that any intervention reduced relapse.

Trial registration

Current Controlled Trials ISRCTN17160673 (IMPACT); Current Controlled Trials ISRCTN22581937 (InterACT); Current Controlled Trials ISRCTN88275061 (ReCAP).

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 3, No. 2. See the NIHR Journals Library website for further project information.

Continued cannabis use at one year follow up is associated with elevated mood and lower global functioning in bipolar I disorder

BACKGROUND

There is limited knowledge about how environmental factors affect the course of bipolar disorder (BD). Cannabis has been proposed as a potential risk factor for poorer course of illness, but the role of cannabis use has not been studied in a first treatment BD I sample.

METHODS

The present study examines the associations between course of illness in first treatment BD I and continued cannabis use, from baseline to one year follow up. Patients (N = 62) with first treatment DSM-IV BD I were included as part of the Thematically Organized Psychosis study (TOP), and completed interviews and self-report questionnaires at both baseline and follow up. Cannabis use within the last six months at baseline and use between baseline and follow up ("continued use") was recorded.

RESULTS

After controlling for confounders, continued cannabis use was significantly associated with elevated mood (YMRS) and inferior global functioning (GAF-F) at follow up. Elevated mood mediated the effect of cannabis use on global functioning.

CONCLUSIONS

These results suggest that cannabis use has clinical implications for the early course of BD by increasing mood level. More focus on reducing cannabis use in clinical settings seems to be useful for improving outcome in early phase of the disorder.

Cannabis and bipolar disorder: does quitting cannabis use during manic/mixed episode improve clinical/functional outcomes?

OBJECTIVE

To examine whether bipolar disorder patients who stop cannabis use during a manic/mixed episode have better clinical and functional outcomes than continued use or never use.

METHOD

Data from the European Mania in Bipolar Longitudinal Evaluation of Medication (EMBLEM), a 2-year prospective observational study in adults with a manic/mixed episode of bipolar disorder, was used. Three cannabis use groups were: current use (between 12-week and 24-month visits); no current but previous use (during first 12 weeks); and never use. Associations between cannabis use and outcomes were analyzed using regression models.

RESULTS

Of 1922 patients analyzed, 6.9% were current users, 4.6% previous users, and 88.5% never users. Clinical outcomes differed between groups (P<0.019): previous users had highest rates of remission (68.1%) and recovery (38.7%), and lowest rates of recurrence (42.1%) and relapse (29.8%). Logistic regression showed previous users had similar outcomes to never users (all P>0.05), whereas current users had lower recovery (P=0.004) and remission (P=0.014), higher recurrence (P=0.014), greater work impairment (P=0.016), and were more likely not to be living with partner (P=0.006) than never users.

CONCLUSION

Bipolar patients who stop using cannabis during manic/mixed episode have similar clinical and functional outcomes to never users, while continued use is associated with higher risk of recurrence and poorer functioning.

Stimulant and other substance use disorders in schizophrenia: prevalence, correlates and impacts in a population sample

OBJECTIVES

Stimulants may worsen psychotic symptoms but there is limited evidence about the impact of stimulant abuse in people with schizophrenia. This study examined the prevalence and correlates of stimulant and other drug disorders in a population-based sample of people with schizophrenia, examining associations with frequent service use, physical health comorbidities and accommodation instability.

METHODS

New South Wales (NSW) hospital, community mental health and emergency department data were used to examine health service contact over 5 years in 13,624 people with a diagnosis of schizophrenia. Associations of stimulant disorders were examined with multinomial logistic regression, comparing people with no substance disorders to those with cannabis disorders, stimulant disorders or both.

RESULTS

Of people with schizophrenia, 51% had substance disorders, including 14% with stimulant disorders. Stimulant disorders were more common in young adults and in urban areas, less common in migrants, and unrelated to initial social disadvantage. More than 80% of those with stimulant disorders also had cannabis disorders. Service use and harms were most common in this group, including frequent mental health admissions (59%), frequent emergency department presentations (52%), admissions with injury or self-harm (44%), infectious disease diagnoses (22%), multiple changes of residence (61%), movement to more disadvantaged locations (42%) and periods of homelessness (18%). People with stimulant disorders alone had higher rates of self-harm, infectious disease and non-mental health admissions than people with cannabis disorders alone.

CONCLUSIONS

Stimulant disorders occur in people with schizophrenia and in first-episode psychosis at rates more than 10 times that of the broader population. Stimulant disorders are likely to worsen the burden of psychosis, and strategies are needed to engage and support the highly disadvantaged group of people with schizophrenia who have cannabis and stimulant disorders.

Integrated treatment of first episode psychosis with online training (e-learning): study protocol for a randomised controlled trial

BACKGROUND

The integrated treatment of first episode psychosis has been shown to improve functionality and negative symptoms in previous studies. In this paper, we describe a study of integrated treatment (individual psychoeducation complementary to pharmacotherapy) versus treatment as usual, comparing results at baseline with those at 6-month re-assessment (at the end of the study) for these patients, and online training of professionals to provide this complementary treatment, with the following objectives: 1) to compare the efficacy of individual psychoeducation as add-on treatment versus treatment as usual in improving psychotic and mood symptoms; 2) to compare adherence to medication, functioning, insight, social response, quality of life, and brain-derived neurotrophic factor, between both groups; and 3) to analyse the efficacy of online training of psychotherapists.

METHODS/DESIGN

This is a single-blind randomised clinical trial including patients with first episode psychosis from hospitals across Spain, randomly assigned to either a control group with pharmacotherapy and regular sessions with their psychiatrist (treatment as usual) or an intervention group with integrated care including treatment as usual plus a psychoeducational intervention (14 sessions). Training for professionals involved at each participating centre was provided by the coordinating centre (University Hospital of Álava) through video conferences. Patients are evaluated with an extensive battery of tests assessing clinical and sociodemographic characteristics (Positive and Negative Syndrome Scale, State-Trait Anxiety Inventory, Liebowitz Social Anxiety Scale, Hamilton Rating Scale for Depression, Scale to Assess Unawareness of Mental Disorders, Strauss and Carpenter Prognostic Scale, Global Assessment of Functioning Scale, Morisky Green Adherence Scale, Functioning Assessment Short Test, World Health Organization Quality of Life instrument WHOQOL-BREF (an abbreviated version of the WHOQOL-100), and EuroQoL questionnaire), and brain-derived neurotrophic factor levels are measured in peripheral blood at baseline and at 6 months. The statistical analysis, including bivariate analysis, linear and logistic regression models, will be performed using SPSS.

DISCUSSION

This is an innovative study that includes the assessment of an integrated intervention for patients with first episode psychosis provided by professionals who are trained online, potentially making it possible to offer the intervention to more patients.

TRIAL REGISTRATION

NCT01783457 clinical trials.gov. Date of registration in primary registry 23 January 2013.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Longitudinal relationship between expressed emotion and cannabis misuse in young people with first-episode psychosis

Carers' expressed emotion (EE) and patients' cannabis misuse are two of the most robust predictors of psychotic relapse. We aimed to examine the temporal relationship between EE and cannabis misuse. Sixty-three key carers of young people with first-episode psychosis (FEP) were assessed at baseline and 7-month follow-up. EE was measured in carers using the Family Questionnaire (FQ) and cannabis misuse in patients using the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). Correlational and hierarchical logistic regression analyses were conducted to examine the temporal relationship between EE components (i.e. criticism and emotional over involvement) and cannabis misuse. Carers' criticism at baseline significantly predicted cannabis misuse according to the ASSIST at 7-month follow-up. The association remained significant after controlling for baseline symptom severity and social functioning (B=0.15, P=.02). Conversely, baseline cannabis misuse was not associated with carers' criticism at 7-month follow-up. Patients in families with high criticism showed a tendency to increase cannabis misuse over time whereas the opposite trend was observed in those with carers with low criticism. A family environment characterized by high criticism may become a key risk factor for worsening cannabis misuse over time in young people with FEP. Further studies should investigate the potential mechanisms (e.g., patient's anxiety or perceived stress) through which criticism increases cannabis misuse in FEP.

Cannabis and stimulant disorders and readmission 2 years after first-episode psychosis

BACKGROUND

Few studies have examined the impact of stimulant use on outcome in early psychosis. Ceasing substance use may lead to positive outcomes in psychosis.

AIMS

To examine whether baseline cannabis or stimulant disorders and ongoing drug use predict readmission within 2 years of a first psychosis admission.

METHOD

Predictors of readmission were examined with Cox regression in 7269 people aged 15-29 years with a first psychosis admission.

RESULTS

Baseline cannabis and stimulant disorders did not predict readmission. A stimulant disorder diagnosis prior to index psychosis admission predicted readmission, but a prior cannabis disorder diagnosis did not. Ongoing problem drug use predicted readmission. The lowest rate of readmission occurred in people whose baseline drug problems were discontinued.

CONCLUSIONS

Prior admissions with stimulant disorder may be a negative prognostic sign in first-episode psychosis. Drug use diagnoses at baseline may be a good prognostic sign if they are identified and controlled.

Systematic meta-analysis of outcomes associated with psychosis and co-morbid substance use

OBJECTIVE

To compare the symptoms and social function of patients with psychosis and current substance use to those with psychosis and no history of substance use.

METHOD

The databases EMBASE, MEDLINE and PsycINFO were searched for peer-reviewed publications in English that reported the characteristics of patients with psychotic illness who were current substance users and those who had never used substances. The searches yielded 22 articles that met the inclusion criteria. Meta-analysis was used to compare four key outcome variables: positive symptoms, negative symptoms, depression and social function - and three secondary outcomes: violence, self-harm and hospital admissions.

RESULTS

Current substance-using patients were significantly younger than non-substance-using patients and were more likely to be male, but did not differ in age at onset of psychosis or in their level of education. Current substance users had higher ratings of positive symptoms and were more likely to have a history of violence. Older studies reported a stronger association between current substance use and positive symptoms than more recently published studies. Current substance users did not differ from non-users on measurements of negative symptoms, depressive symptoms, social function, self-harm, or the number of hospital admissions.

CONCLUSION

Current substance users with psychosis may have more severe positive symptoms than patients who have never used substances, but this result should be interpreted with caution because of demographic differences between substance users and non-substance users.

Impact of Cannabis Use on the Development of Psychotic Disorders

The link between cannabis use and psychosis comprises three distinct relationships: acute psychosis associated with cannabis intoxication, acute psychosis that lasts beyond the period of acute intoxication, and persistent psychosis not time-locked to exposure. Experimental studies reveal that cannabis, tetrahydrocannabinol (THC) and synthetic cannabinoids reliably produce transient positive, negative, and cognitive symptoms in healthy volunteers. Case-studies indicate that cannabinoids can induce acute psychosis which lasts beyond the period of acute intoxication but resolves within a month. Exposure to cannabis in adolescence is associated with a risk for later psychotic disorder in adulthood; this association is consistent, temporally related, shows a dose-response, and is biologically plausible. However, cannabis is neither necessary nor sufficient to cause a persistent psychotic disorder. More likely it is a component cause that interacts with other factors to result in psychosis. The link between cannabis and psychosis is moderated by age at onset of cannabis use, childhood abuse and genetic vulnerability. While more research is needed to better characterize the relationship between cannabinoid use and the onset and persistence of psychosis, clinicians should be mindful of the potential risk of psychosis especially in vulnerable populations, including adolescents and those with a psychosis diathesis.

Trajectories of antipsychotic response in drug-naive schizophrenia patients: results from the 6-month ESPASS follow-up study

OBJECTIVE

The aim of this study was to explore any heterogeneity in the 6-month clinical response in patients with antipsychotic drug-naive schizophrenia and to determine predictors of that outcome.

METHOD

467 patients with antipsychotic drug-naive schizophrenia were included in France nationwide and followed up over 6 months. To identify trajectories of clinical response, a latent class growth analysis (LCGA) was performed using the Clinical Global Impression-Severity (CGI-S) scores at baseline, 1, 3, and 6 months. Regression models were used to identify predictors of trajectory membership.

RESULTS

Five trajectory groups were identified: a rapid response group (n = 45), a gradual response group (n = 204), patients remaining mildly ill (n = 133), patients remaining very ill (n = 23), and a group with unsustained clinical response (n = 62). Predictors of the 6-month clinical response were baseline CGI-S score (odds ratio: 3.1; 95% confidence interval, 2.1-4.4) and negative symptoms (OR, 1.5; 95% CI, 1.2-1.9). The sole predictor of rapid response as compared to gradual response was employment (OR, 2.5; 95% CI, 1.2-4.9).

CONCLUSION

Clinical response in patients with schizophrenia 6 months after a first-ever antipsychotic drug initiation is heterogeneous. Therapeutic strategies in first episode should take account of symptom severity and early clinical response, to maximize the chances of recovery.

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

BACKGROUND

Cannabis use has been reported to be associated with an earlier onset of symptoms in patients with first-episode psychosis, and a worse outcome in those who continue to take cannabis. In general, studies have concentrated on symptoms of psychosis rather than mania. In this study, using a longitudinal design in a large naturalistic cohort of patients with first-episode psychosis, we investigated the relationship between cannabis use, age of presentation to services, daily functioning, and positive, negative and manic symptoms.

METHOD

Clinical data on 502 patients with first-episode psychosis were collected using the MiData audit database from seven London-based Early Intervention in psychosis teams. Individuals were assessed at two time points--at entry to the service and after 1 year. On each occasion, the Positive and Negative Syndrome Scale, Young Mania Rating Scale and Global Assessment of Functioning Scale disability subscale were rated. At both time points, the use of cannabis and other drugs of abuse in the 6 months preceding each assessment was recorded.

RESULTS

Level of cannabis use was associated with a younger age at presentation, and manic symptoms and conceptual disorganization, but not with delusions, hallucinations, negative symptoms or daily functioning. Cannabis users who reduced or stopped their use following contact with services had the greatest improvement in symptoms at 1 year compared with continued users and non-users. Continued users remained more symptomatic than non-users at follow-up.

CONCLUSIONS

Effective interventions for reducing cannabis use may yield significant health benefits for patients with first-episode psychosis.

Gone to Pot - A Review of the Association between Cannabis and Psychosis

Cannabis is the most commonly used illicit drug worldwide, with ~5 million daily users worldwide. Emerging evidence supports a number of associations between cannabis and psychosis/psychotic disorders, including schizophrenia. These associations-based on case-studies, surveys, epidemiological studies, and experimental studies indicate that cannabinoids can produce acute, transient effects; acute, persistent effects; and delayed, persistent effects that recapitulate the psychopathology and psychophysiology seen in schizophrenia. Acute exposure to both cannabis and synthetic cannabinoids (Spice/K2) can produce a full range of transient psychotomimetic symptoms, cognitive deficits, and psychophysiological abnormalities that bear a striking resemblance to symptoms of schizophrenia. In individuals with an established psychotic disorder, cannabinoids can exacerbate symptoms, trigger relapse, and have negative consequences on the course of the illness. Several factors appear to moderate these associations, including family history, genetic factors, history of childhood abuse, and the age at onset of cannabis use. Exposure to cannabinoids in adolescence confers a higher risk for psychosis outcomes in later life and the risk is dose-related. Individuals with polymorphisms of COMT and AKT1 genes may be at increased risk for psychotic disorders in association with cannabinoids, as are individuals with a family history of psychotic disorders or a history of childhood trauma. The relationship between cannabis and schizophrenia fulfills many but not all of the standard criteria for causality, including temporality, biological gradient, biological plausibility, experimental evidence, consistency, and coherence. At the present time, the evidence indicates that cannabis may be a component cause in the emergence of psychosis, and this warrants serious consideration from the point of view of public health policy.

Cannabis use and involuntary admission may mediate long-term adherence in first-episode psychosis patients: a prospective longitudinal study

BACKGROUND

This study aimed to examine factors associated with treatment adherence in first-episode psychosis (FEP) patients followed up over 8 years, especially involuntary first admission and stopping cannabis use.

METHODS

This prospective, longitudinal study of FEP patients collected data on symptoms, adherence, functioning, and substance use. Adherence to treatment was the main outcome variable and was categorized as 'good' or 'bad'. Cannabis use during follow-up was stratified as continued use, stopped use, and never used. Bivariate and logistic regression models identified factors significantly associated with adherence and changes in adherence over the 8-year follow-up period.

RESULTS

Of the 98 FEP patients analyzed at baseline, 57.1% had involuntary first admission, 74.4% bad adherence, and 52% cannabis use. Good adherence at baseline was associated with Global Assessment of Functioning score (p = 0.019), Hamilton Depression Rating Scale score (p = 0.017) and voluntary admission (p < 0.001). Adherence patterns over 8 years included: 43.4% patients always bad, 26.1% always good, 25% improved from bad to good. Among the improved adherence group, 95.7% had involuntary first admission and 38.9% stopped cannabis use. In the subgroup of patients with bad adherence at baseline, involuntary first admission and quitting cannabis use during follow up were associated with improved adherence.

CONCLUSIONS

The long-term association between treatment adherence and type of first admission and cannabis use in FEP patients suggest targets for intervention to improve clinical outcomes.

Treated incidence and baseline characteristics of substance induced psychosis in a Norwegian catchment area

BACKGROUND

Substance misuse is a well-recognized co-morbidity to psychosis and has been linked to poor prognostic outcomes in patients. Researchers have yet to investigate the difference in rates and characteristics between first-episode Substance Induced Psychosis (SIP) and primary psychosis. We aimed at comparing patients with SIP to primary psychosis patients with or without substance misuse at baseline.

METHODS

Thirty SIP patients, 45 primary psychosis patients with substance misuse (PS) and 66 primary psychosis patients without substance misuse (PNS) in a well-defined Norwegian catchment area were included from 2007-2011. Assessments included symptom levels (PANSS), diagnostic interviews (SCID), premorbid function scale (PAS) and global functioning (GAF f/s).

RESULTS

Treated incidence for SIP was found to be 6.5/100 000 persons per year, 9.7/100 000 persons per year for PS and 24.1/100 000 persons per year for PNS (15-65 yrs). Patients who had substance misuse (PS and SIP) were more likely to be male. Duration of Untreated Psychosis (DUP) was significantly shorter in the SIP group (5.0 wks., p = 0.003) and these had more positive symptoms on the PANSS (p = 0.049). SIP patients also did poorer on early youth academic levels on the PAS.

CONCLUSIONS

Yearly treated incidence of SIP is 6.5/100 000 persons per year in a Norwegian catchment area. SIP patients have short DUPs, are more likely to be male, have more positive symptoms at baseline and poorer premorbid academic scores in early adolescence. Follow-up will evaluate stability of diagnosis and characteristics.

Cannabis use and cognitive functions in at-risk mental state and first episode psychosis

BACKGROUND

Meta-analyses suggest that schizophrenia patients with a history of cannabis use have less impaired cognitive functioning compared to patients without cannabis use.

AIMS

The objective of this study was to assess the association between recency and frequency of cannabis use and cognitive functioning in at-risk mental state for psychosis (ARMS) and first episode psychosis (FEP) individuals.

METHODS

One hundred thirty-six participants completed a cognitive test battery and were assessed for current and past cannabis use. Analyses of covariance models were applied to evaluate the main effects of cannabis use and patient group (ARMS vs. FEP) as well as their interactions on cognitive functioning.

RESULTS

No differences were observed in cognitive performance between current, former, and never users, and there were no significant interactions between cannabis use and patient group. Furthermore, within the group of current cannabis users, the frequency of cannabis use was not significantly associated with cognitive functioning.

CONCLUSION

The results of the present study do not support the notion that FEP patients and ARMS individuals with a history of cannabis use have less impaired cognitive functioning compared to those without cannabis use.

Improving physical health and reducing substance use in psychosis--randomised control trial (IMPACT RCT): study protocol for a cluster randomised controlled trial

BACKGROUND

Cardiovascular morbidity and mortality is increased in individuals with severe mental illnesses.We set out to establish a multicentre, two arm, parallel cluster randomized controlled trial (RCT) of a health promotion intervention (HPI), IMPACT Therapy. The patient-tailored IMPACT Therapy aims to target one or more health behaviours from a pre-defined list that includes cannabis use; alcohol use; other substance use; cigarette smoking; exercise; diet and diabetic control, prioritising those identified as problematic by the patient, taking a motivational interviewing and CBT approach.

METHODS

Impact therapy will be delivered by care coordinators in the community to the treatment group and will be compared to treatment as usual (TAU). The main hypothesis is that the addition of IMPACT Therapy (HPI) to TAU will be more effective than TAU alone in improving patients' quality of life as measured by the Short Form-36, including mental health and physical health subscales on completion of the intervention at 12 months post randomisation. A subsidiary hypothesis will be that addition of IMPACT Therapy (HPI) will be more cost-effective than TAU alone in improving health in people with SMI 12 months from baseline. The IMPACT therapy patient groups' improvement in quality of life, as well as its cost effectiveness, is hypothesised to be maintained at 15 months. Outcomes will be analyzed on an intention-to-treat (ITT) basis.

DISCUSSION

The results of the trial will provide information about the effectiveness of the IMPACT therapy programme in supporting community mental health teams to address physical comorbidity in severe mental illness.

TRIAL REGISTRATION

ISRCTN58667926.

Cannabis and psychosis: have we found the missing links?

BACKGROUND

The association between cannabis and psychosis has long been a matter of debate, with cannabis widely perceived as a harmless recreational drug.

METHODS

Electronic bibliographic databases like PubMed and Google Scholar were searched using the format "(psychosis or schizophrenia or synonyms) and (cannabis or synonyms)". Cross-linked searches were made taking the lead from key articles. Recent articles and those exploring the genetic factors or gene-environment interaction between cannabis use and psychosis were focussed upon.

RESULTS

Heavy cannabis use at a n young age, in association with genetic liability to psychosis and exposure to environmental stressors like childhood trauma and urban upbringing increases the risk of psychotic outcome in later life.

CONCLUSION

Cannabis acts as a component cause of psychosis, that is, it increases the risk of psychosis in people with certain genetic or environmental vulnerabilities, though by itself, it is neither a sufficient nor a necessary cause of psychosis. Although significant progress has been made over the last few years, we are yet to find all the missing links. Further work is necessary to identify all the factors that underlie individual vulnerability to cannabis-related psychosis and to elucidate the biological mechanisms underlying this risk.

Differences in associations between cannabis and stimulant disorders in first admission psychosis

BACKGROUND

Substance use in early psychosis is associated with male gender and earlier onset. Evidence about other correlates of substance use is less consistent. Stimulants (e.g. methamphetamine, cocaine) may precipitate psychosis. However the associations of stimulant disorders in early psychosis are difficult to examine because of lower prevalence and overlap with cannabis disorders.

METHODS

Hospital records were used to identify 9919 persons aged 15-29 with a first hospital admission with psychosis in New South Wales (NSW), Australia. Correlates of illicit drug disorders, cannabis disorders and stimulant disorders were examined using univariate and multivariate logistic regression.

RESULTS

Half of first psychosis admissions had comorbid substance diagnoses. Cannabis and stimulant disorders were increased more than ten-fold compared to the age-matched Australian population. Stimulant disorders were equally common in women and men and associated with urban location, social advantage and older age at first admission. Cannabis disorders were associated with male gender, younger age and non-metropolitan location. Diagnoses of drug-induced psychoses were more strongly associated with stimulants than with cannabis. Compared to people with cannabis diagnoses alone, those with both cannabis and stimulant disorders were older, more likely to have a diagnosis of drug-induced psychosis and more likely to have comorbid alcohol disorders.

CONCLUSIONS

Cannabis is the most commonly used substance in psychosis, and the associations of illicit drug use in psychoses are largely those of cannabis disorders. There are significant differences between the personal, socio-economic and diagnostic correlates of cannabis and stimulant disorders in young people with first admission psychosis.

Do former substance users with psychosis differ in their symptoms or function from non-substance users? A systematic meta-analysis

OBJECTIVE

To compare the symptoms and function of patients with psychosis who have ceased using substances to those who have psychosis but do not have a history of substance use.

METHOD

The databases EMBASE, MEDLINE and PsycINFO were searched for peer-reviewed publications in English reporting the characteristics of patients with psychotic illness who had stopped using substances and those who had never used substances. The searches yielded 20 articles that met the inclusion criteria. Four key outcome variables - positive symptoms, negative symptoms, depression and global function - and four other outcome measures reported in five or more studies were examined using meta-analysis.

RESULTS

Former substance-using patients were significantly younger than non-substance-using patients and were more likely to be male, but did not differ in age at onset of psychosis or in their level of education. There were no significant differences between former substance users and non-substance users in ratings of positive symptoms, negative symptoms, depression or global function. Among first-episode patients there was a trend towards former substance users having less severe depressive symptoms than non-substance users. In contrast, among non-first-episode patients, former substance users had significantly more depressive symptoms than non-substance users. In studies rated as being of higher quality, former substance users had significantly less severe positive symptoms than non-substance users.

CONCLUSION

The absence of significant differences between the two groups suggests that a history of substance use is not a poor prognostic indicator for patients who are able to stop using substances.

Screening for substance use disorders in first-episode psychosis: implications for readmission

INTRODUCTION

Screening of substance use may prove useful to prevent readmission after the first episode of psychosis. The aim of the present study was to evaluate the influence of drug use on readmission risk in a first-episode psychosis sample, and to determine whether the cannabis/cocaine subscale of the Dartmouth Assessment of Lifestyle Inventory (DALI) is a better predictive instrument than urinary analysis.

METHODS

After admission, first-episode psychotic patients were interviewed for substance use and assessed with the DALI scale. They also underwent blood and urine sampling. Time to readmission was studied as a dependent outcome. The Kaplan-Meier estimator was applied to estimate the survival curves for bivariate analysis. The Cox proportional hazards model for multivariate analysis was assessed in order to control for potential confounders. ROC curve and validity parameters were used to assess validity to detect readmission.

RESULTS

Fifty-eight patients were included. The DALI cannabis/cocaine subscale and urinalysis were associated with increased readmission risk in survival curves, mainly the first five years of follow-up. After controlling for potential confounding variables for readmission, only the DALI cannabis/cocaine subscale remained as a significant risk factor. In terms of validity, the DALI cannabis/cocaine subscale was more sensitive than urinalysis. Alcohol assessments were not related to readmission.

CONCLUSIONS

The findings demonstrated that a quick screening self-report scale for cannabis/cocaine use disorders is superior to urinary analysis for predicting readmission. Future research should consider longitudinal assessments of brief validated screening tests in order to evaluate their benefits in preventing early readmission in first-episode psychosis.

Plasma brain-derived neurotrophic factor levels, learning capacity and cognition in patients with first episode psychosis

BACKGROUND

Cognitive impairments are seen in first psychotic episode (FEP) patients. The neurobiological underpinnings that might underlie these changes remain unknown. The aim of this study is to investigate whether Brain Derived Neurotrophic Factor (BDNF) levels are associated with cognitive impairment in FEP patients compared with healthy controls.

METHODS

45 FEP patients and 45 healthy controls matched by age, gender and educational level were selected from the Basque Country area of Spain. Plasma BDNF levels were assessed in healthy controls and in patients. A battery of cognitive tests was applied to both groups, with the patients being assessed at 6 months after the acute episode and only in those with a clinical response to treatment.

RESULTS

Plasma BDNF levels were altered in patients compared with the control group. In FEP patients, we observed a positive association between BDNF levels at six months and five cognitive domains (learning ability, immediate and delayed memory, abstract thinking and processing speed) which persisted after controlling for medications prescribed, drug use, intelligence quotient (IQ) and negative symptoms. In the healthy control group, BDNF levels were not associated with cognitive test scores.

CONCLUSION

Our results suggest that BDNF is associated with the cognitive impairment seen after a FEP. Further investigations of the role of this neurotrophin in the symptoms associated with psychosis onset are warranted.

Medication adherence mediates the impact of sustained cannabis use on symptom levels in first-episode psychosis

Both medication non-adherence and co-morbid cannabis abuse are associated with poor clinical outcome in first episode psychosis (FEP). The nature of interaction between adherence to medication and continued cannabis use remains unexplored. The objectives of this study were to examine variation in medication adherence associated with cessation or continuation of cannabis use, and to determine the impact of interaction between cannabis use and adherence to medication on symptom outcome at 12 months. From a consecutive patient cohort (N=192) with a DSM-IV diagnosis of a FEP, 62 patients who met DSM-IV criteria for a currently active cannabis abuse disorder were followed up for one year. Complete data on repeated measures of medication adherence, symptoms, and cannabis use were available for 48 of the 62 patients. Twenty-eight patients (58.7%) continued while 20 (41.2%) stopped cannabis use after entering treatment. While both groups were relatively non-adherent at six months, 25/28 (92%) of the former group became adherent compared to 8/20 (40%) of those who stopped cannabis use (p<.01). While there was no overall effect of continued cannabis use on symptom levels at 12 months, after controlling for medication adherence patients with continuous cannabis use had significantly higher level of symptoms (F(1,30)=2.74, p=0.03). FEP patients with an active cannabis use disorder may make a choice of either stopping cannabis and not taking medications or continuing cannabis but becoming more adherent to medications, adherence to medication appears to help both groups but continuous users remain at higher risk of poor symptom outcome even while on medication.

Empirical evidence for psychopharmacologic treatment in early-onset psychosis and schizophrenia

Psychotic symptoms presenting in youth can be clinically complex and require that a child and adolescent psychiatrist use significant skill in making a diagnosis and initiating treatment. There are a number of illnesses to rule out before making a diagnosis of early-onset schizophrenia in particular. Psychosis in youth has significant associated morbidity and places high demands not only on families but also on the medical and educational systems. More effective pharmacologic and nonpharmacologic treatments for psychosis are needed. Nonpharmacologic therapies targeting relatively treatment-resistant domains of dysfunction such as neurocognition are also necessary as adjunctive treatments to our extant pharmacologic agents.

Does giving up substance use work for patients with psychosis? A systematic meta-analysis

OBJECTIVE

To assess the extent to which ceasing the use of cannabis or other substances reduces the symptoms and social disability associated with psychotic illness.

METHODS

The electronic databases CINAHL, EMBASE, MEDLINE and PsycINFO were searched for peer-reviewed publications in English that report data about the characteristics of current and former substance-using patients diagnosed with psychotic illnesses. The searches yielded 328 articles, of which 23 studies met the inclusion criteria. Four key outcome variables; positive symptoms, negative symptoms, ratings of depression and global function, and five other measures of outcome that were reported in five or more studies were examined using meta-analysis.

RESULTS

Current substance-using patients were significantly younger than former substance-using patients (standardised mean difference (SMD) = -0.38), but did not differ in age at onset of psychosis, sex, level of education or marital status. Current substance users had higher scores on rating scales of positive symptoms (SMD = 0.29) and depression (SMD = 0.36), and lower scores on global function (SMD = -0.26) when compared with former substance users. There was a significant improvement in the ratings of positive symptoms, mood and global function among patients who stopped using substances during the first episode of psychosis, while improvements in the symptoms of patients with a more established psychotic illness did not reach statistical significance.

CONCLUSION

The results suggest that substance use contributes to both the symptoms and the burden of disability experienced by patients with psychosis. Patients in the early stages of psychotic illness should be informed about the benefits of giving up substances earlier, rather than later in the illness. Psychiatric services should regard the treatment of substance use as an integral part of the treatment of psychotic disorders.

Total exposure duration and proximity of cessation of cannabis use predict severity of sub-clinical psychotic symptoms among former users

In a non-clinical military enrolment setting, former cannabis users (N=81), compared to substance-naïve controls (N=132), endorsed markedly elevated rates of schizotypy subscale scores on the Schizotypal Personality Questionnaire (SPQ). Total duration of exposure and proximity of cessation of cannabis use also had an important impact on the severity of psychosis-like symptoms.

The effect of cannabis use and cognitive reserve on age at onset and psychosis outcomes in first-episode schizophrenia

OBJECTIVE

Cannabis use is associated with a younger age at onset of psychosis, an indicator of poor prognosis, but better cognitive function, a positive prognostic indicator. We aimed to clarify the role of age at onset and cognition on outcomes in cannabis users with first-episode schizophrenia as well as the effect of cannabis dose and cessation of use.

METHODS

Ninety-nine patients without alcohol or substance abuse other than cannabis were divided into lifetime users and never-users of cannabis and compared on measures of premorbid function, cognition, and clinical outcome.

RESULTS

Cannabis users demonstrated better cognition at psychosis onset, which was explained by higher premorbid IQ. They also showed better social function and neither measure changed over the subsequent 15 months. Cannabis users had an earlier age at onset of psychosis, and there was a strong linear relationship between age at first cannabis use and age at onset of both prodromal and psychotic symptoms. Cannabis use spontaneously declined over time with 3-quarters of users giving up altogether. Later age at first cannabis use predicted earlier cessation of use and this in turn was linked to fewer positive psychotic symptoms and days in hospital during the first 2 years.

CONCLUSIONS

Cannabis use brings forward the onset of psychosis in people who otherwise have good prognostic features indicating that an early age at onset can be due to a toxic action of cannabis rather than an intrinsically more severe illness. Many patients abstain over time, but in those who persist, psychosis is more difficult to treat.

Cannabis use and anticipatory pleasure as reported by subjects with early psychosis and community controls

BACKGROUND

There is evidence of decreased pleasure and deficits in the anticipation of reward in both psychotic illness and drug addiction. Individuals with low anticipatory pleasure may preferentially engage in behaviours associated with immediate reward such as cannabis use.

METHOD

Ninety-one psychosis patients and 91 controls without history of psychosis were administered the Temporal Experience of Pleasure Scale (TEPS), a self report which measures anticipatory and consummatory pleasure. Cannabis use diagnosis was assessed using the Structured Clinical Interview for DSM IV (SCID). Subjects reported the frequency of cannabis consumption and time since last use.

RESULTS

Patients did not show a significant deficit in anticipatory or consummatory pleasure compared to controls; however, patients with an active cannabis-use disorder tended to have lower consummatory pleasure than controls with active cannabis disorder (p<.05). Patients who continued to use cannabis during treatment of their first episode of psychosis reported significantly lower anticipatory pleasure compared to those who had a lifetime cannabis diagnosis but were able to maintain abstinence (F(1,60)=5.6, p=.021). Frequency of cannabis use was negatively correlated to anticipatory and consummatory pleasure (Pearson R=-.46, -.48 respectively) in 37 patients currently using cannabis but not in 46 cannabis-using controls (partial R=-.04, -.07 respectively).

CONCLUSION

Anticipatory pleasure may not be decreased in early psychosis patients. Lower hedonic response may be associated with persistent, heavy cannabis use in patients in the early phase of psychotic disorders.

Cannabis and cognitive performance in psychosis: a cross-sectional study in patients with non-affective psychotic illness and their unaffected siblings

BACKGROUND

The relationship between cannabis use and cognitive functioning in patients with psychosis has yielded contradictory findings. In individuals at genetic high risk for psychosis, information is sparse. The aim of this study was to assess the association between recency and frequency of cannabis use and cognitive functioning in patients with psychosis and their unaffected siblings.

METHOD

We conducted a cross-sectional study in 956 patients with non-affective psychosis, 953 unaffected siblings, and 554 control subjects. Participants completed a cognitive test battery including assessments of verbal learning, set shifting, sustained attention, processing speed, working memory, acquired knowledge, reasoning and problem solving and social cognition. Cannabis use was assessed by urinalysis and by the Composite International Diagnostic Interview. Using random-effect regression models the main effects of cannabis (recency and frequency) and the interaction with status (patient, sibling, control) on cognitive functioning were assessed.

RESULTS

Current cannabis use was associated with poorer performance on immediate verbal learning, processing speed and working memory (Cohen's d -0.20 to -0.33, p<0.005). Lifetime cannabis use was associated with better performance on acquired knowledge, facial affect recognition and face identity recognition (Cohen's d+0.17 to +0.33, p<0.005). There was no significant interaction between cannabis and status on cognitive functioning.

CONCLUSIONS

Lifetime cannabis-using individuals might constitute a subgroup with a higher cognitive potential. The residual effects of cannabis may impair short-term memory and processing speed.

Psychosis and smoking cessation: difficulties in quitting associated with sex and substance abuse

No prospective studies of first psychotic episodes have explored sex differences in smoking cessation. The aim of this study was to determine the influence of sex and substance abuse on smoking cessation during an 8-year follow-up of patients after a first psychotic episode. Logistic regression modeling was used to identify factors associated with smoking cessation by sex. To examine for sex variable interactions, the following two methods were used: 1) for other clinical variables, mixed analyses were calculated; and 2) for use of other substances, logistic regression models were performed only in the substance users. At baseline, 79% of men and 84% of women were current smokers. Lower smoking cessation after 8 years was associated with female sex (odds ratio, OR=0.30; 95% confidence intervals, CIs=0.12-0.75) and treatment with typical antipsychotics (OR=0.30, CIs=0.10-0.93). In a logistic regression model of alcohol users, those who used alcohol continuously were less likely to stop smoking (adjusted OR=0.22, CI=0.05-1.0). Among patients who continued using cannabis, female sex was associated with significant lower smoking cessation (adjusted OR=0.03, CI=0.001-0.77). Sex may act as a moderator in smoking cessation after a first psychotic episode. Smoking cessation interventions in these patients should consider sex differences and comorbidity with alcohol and cannabis use.

The association between delusional-like experiences, and tobacco, alcohol or cannabis use: a nationwide population-based survey

BACKGROUND

Previous population-based studies have found that delusional-like experiences (DLE) are prevalent in the community, and are associated with a wide range of mental health disorders including substance use. The aim of the study was to explore the association between DLE and three commonly used substances--tobacco, alcohol and cannabis.

METHODS

Subjects were drawn from the Australian National Survey of Mental Health and Wellbeing 2007. The Composite International Diagnostic Interview was used to identify DLE, common psychiatric disorders, and substance use. We examined the relationship between the variables of interest using logistic regression, adjusting for potential confounding factors.

RESULTS

Of 8,773 participants, 8.4% (n=776) subjects endorsed one or more DLE. With respect to tobacco use, compared to nonusers, DLE were more common in those who (a) had daily use, (b) commenced usage aged 15 years or less, and (c) those who smoked heavily (23 or more cigarettes per day). Participants with cannabis use disorders were more likely to endorse DLE; this association was most prominent in those with an onset of 16 years or younger. In contrast, the pattern of association between DLE versus alcohol use or dependence was less consistent, however those with early onset alcohol use disorders were more likely to endorse DLE probe items.

CONCLUSIONS

While cannabis use disorders have been previously linked with DLE, our findings linking alcohol and tobacco use and DLE suggest that the influence of these substances on psychosis-related outcomes warrants closer scrutiny in longitudinal prospective studies.

Childhood symptoms of inattention-hyperactivity predict cannabis use in first episode psychosis

BACKGROUND

A history of childhood symptoms of inattention-hyperactivity is often reported in first episode psychosis (FEP) as is cannabis use. In the general population childhood ADHD predicts future cannabis use but the relationship has not been tested in FEP.

METHOD

Parents of patients with a first episode of psychosis (n=75) retrospectively assessed their affected child for symptoms of early-life disorders, namely, attention deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD) using the Child Behaviour Checklist (CBCL). Assessments were made prospectively of cannabis use over two years following a FEP and of SCID diagnosis of cannabis-use disorder.

RESULTS

Childhood hyperactivity-inattention symptoms predicted inability to maintain abstinence from cannabis following treatment (Wald=8.4, p=.004) and lifetime cannabis-use diagnosis (Wald=5.3, p=.022) in a logistic regression controlling for relevant covariates including symptoms of CD and ODD from ages 12 to 18. When the symptom of inattention was considered in place of the hyperactivity-inattention syndrome it predicted cannabis-use diagnosis (Wald=6.4, p=.011) and persistent abstinence from cannabis (Wald=5.3, p=.021). Symptoms of CD and ODD did not predict cannabis use when hyperactivity-inattention symptoms were controlled for.

CONCLUSIONS

Symptoms of childhood inattention-hyperactivity predict subsequent cannabis use in FEP.