Association of pre-onset cannabis, alcohol, and tobacco use with age at onset of prodrome and age at onset of psychosis in first-episode patients

On the proportion of patients who experience a prodrome prior to psychosis onset: A systematic review and meta-analysis

BACKGROUND

Preventing or delaying the onset of psychosis requires identification of those at risk for developing psychosis. For predictive purposes, the prodrome - a constellation of symptoms which may occur before the onset of psychosis - has been increasingly recognized as having utility. However, it is unclear what proportion of patients experience a prodrome or how this varies based on the multiple definitions used.

METHODS

We conducted a systematic review and meta-analysis of studies of patients with psychosis with the objective of determining the proportion of patients who experienced a prodrome prior to psychosis onset. Inclusion criteria included a consistent prodrome definition and reporting the proportion of patients who experienced a prodrome. We excluded studies of only patients with a prodrome or solely substance-induced psychosis, qualitative studies without prevalence data, conference abstracts, and case reports/case series. We searched Ovid MEDLINE, Embase (Ovid), APA PsycInfo (Ovid), Web of Science Core Collection (Clarivate), Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, APA PsycBooks (Ovid), ProQuest Dissertation & Thesis, on March 3, 2021. Studies were assessed for quality using the Critical Appraisal Checklist for Prevalence Studies. Narrative synthesis and proportion meta-analysis were used to estimate prodrome prevalence. I2 and predictive interval were used to assess heterogeneity. Subgroup analyses were used to probe sources of heterogeneity. (PROSPERO ID: CRD42021239797).

RESULTS

Seventy-one articles were included, representing 13,774 patients. Studies varied significantly in terms of methodology and prodrome definition used. The random effects proportion meta-analysis estimate for prodrome prevalence was 78.3% (95% CI = 72.8-83.2); heterogeneity was high (I2 97.98% [95% CI = 97.71-98.22]); and the prediction interval was wide (95% PI = 0.411-0.936). There were no meaningful differences in prevalence between grouped prodrome definitions, and subgroup analyses failed to reveal a consistent source of heterogeneity.

CONCLUSIONS

This is the first meta-analysis on the prevalence of a prodrome prior to the onset of first episode psychosis. The majority of patients (78.3%) were found to have experienced a prodrome prior to psychosis onset. However, findings are highly heterogenous across study and no definitive source of heterogeneity was found despite extensive subgroup analyses. As most studies were retrospective in nature, recall bias likely affects these results. While the large majority of patients with psychosis experience a prodrome in some form, it is unclear if the remainder of patients experience no prodrome, or if ascertainment methods employed in the studies were not sensitive to their experiences. Given widespread investment in indicated prevention of psychosis through prospective identification and intervention during the prodrome, a resolution of this question as well as a consensus definition of the prodrome is much needed in order to effectively direct and organize services, and may be accomplished through novel, densely sampled and phenotyped prospective cohort studies that aim for representative sampling across multiple settings.

Identification and treatment of individuals with childhood-onset and early-onset schizophrenia

Approximately 8 % of patients with schizophrenia are diagnosed before age 18, and 18 % experience their first symptoms before age 18. This narrative review explores the management of patients with early-onset schizophrenia (EOS) and childhood-onset schizophrenia (COS) from diagnosis to their transition to adult care settings. Early diagnosis of schizophrenia in children and adolescents is essential for improving outcomes, but delays are common due to overlapping of symptoms with developmental phenomena and other psychiatric conditions, including substance use, and lack of clinicians' awareness. Once diagnosed, antipsychotic treatment is key, with specific second-generation agents generally being preferred due to better tolerability and their broader efficacy evidence-base in youth. Dosing should be carefully individualized, considering age-related differences in drug metabolism and side effect liability. Clinicians must be vigilant in detecting early non-response and consider switching or dose escalation when appropriate. Since early age of illness onset is a consistent risk factor for treatment-resistant schizophrenia (TRS), clinicians need to be competent in diagnosing TRS and using clozapine. Since COS and EOS are associated with cognitive deficits and impaired functioning, psychosocial interventions should be considered to improve overall functioning and quality of life. Good long-term outcomes depend on continuous treatment engagement, and successful transitioning from pediatric to adult care requires careful planning, early preparation, and collaboration between pediatric and adult clinicians. Targeting functional outcomes and quality of life in addition to symptom remission can improve overall patient well-being. Comprehensive evaluations, age-specific assessments, and targeted interventions are needed to address the unique challenges of EOS and COS.

Tobacco smoking, second-hand smoking exposure in relation to psychotic-like experiences in adolescents

BACKGROUND

Previous literature supports that tobacco smoking and second-hand smoking (SHS) exposure were strongly associated with poor mental health in the general population. However, there is a lack of empirical data on the relationship between tobacco smoking, SHS exposure and psychotic-like experiences (PLEs). This study conducted a cross-sectional survey to explore PLEs and the associations of PLEs with tobacco smoking and SHS exposure among adolescents in China.

METHODS

A total sample of 67 182 Chinese adolescents were recruited from Guangdong province in China (53.7% boys, mean age = 12.79 years) from December 17 to 26, 2021. All adolescents have completed self-reported questionnaires on demographic characteristics, smoking status, SHS exposure and PLEs.

RESULTS

Within the sample, only 1.2% of participants had an experience of tobacco smoking while approximately three-fifths reported being exposed to SHS. 10.7% of adolescents reported frequent PLEs over the past month. Adolescents who smoked showed a higher prevalence of PLEs than in non-smoking samples. After controlling for confounders, SHS exposure was a robust risk factor for PLEs with or without the effect of tobacco smoking.

DISCUSSION

These findings support the importance of smoke-free legislation, and anti-smoking measures in educational settings directed at both adolescents and their caregiver, which may decrease occurring rates of PLEs among adolescents.

Assessing evidence supporting cannabis harm reduction practices for adolescents at clinical high-risk for psychosis: a review and clinical implementation tool

Cannabis use is consistently associated with both increased incidence of frank psychotic disorders and acute exacerbations of psychotic symptoms in healthy individuals and people with psychosis spectrum disorders. Although there is uncertainty around causality, cannabis use may be one of a few modifiable risk factors for conversion to psychotic disorders in individuals with Clinical High Risk for Psychosis (CHR-P) syndromes, characterized by functionally impairing and distressing subthreshold psychotic symptoms. To date, few recommendations beyond abstinence to reduce adverse psychiatric events associated with cannabis use have been made. This narrative review synthesizes existing scientific literature on cannabis' acute psychotomimetic effects and epidemiological associations with psychotic disorders in both CHR-P and healthy individuals to bridge the gap between scientific knowledge and practical mental health intervention. There is compelling evidence for cannabis acutely exacerbating psychotic symptoms in CHR-P, but its impact on conversion to psychotic disorder is unclear. Current evidence supports a harm reduction approach in reducing frequency of acute psychotic-like experiences, though whether such interventions decrease CHR-P individuals' risk of conversion to psychotic disorder remains unknown. Specific recommendations include reducing frequency of use, lowering delta-9-tetrahydrocannabinol content in favor of cannabidiol-only products, avoiding products with inconsistent potency like edibles, enhancing patient-provider communication about cannabis use and psychotic-like experiences, and utilizing a collaborative and individualized therapeutic approach. Despite uncertainty surrounding cannabis' causal association with psychotic disorders, cautious attempts to reduce acute psychosis risk may benefit CHR-P individuals uninterested in abstinence. Further research is needed to clarify practices associated with minimization of cannabis-related psychosis risk.

Influence of cannabis use on incidence of psychosis in people at clinical high risk

AIMS

Evidence for case-control studies suggests that cannabis use is a risk factor for the development of psychosis. However, there have been limited prospective studies and the direction of this association remains controversial. The primary aim of the present study was to examine the association between cannabis use and the incidence of psychotic disorders in people at clinical high risk of psychosis. Secondary aims were to assess associations between cannabis use and the persistence of psychotic symptoms, and with functional outcome.

METHODS

Current and previous cannabis use were assessed in individuals at clinical high risk of psychosis (n = 334) and healthy controls (n = 67), using a modified version of the Cannabis Experience Questionnaire. Participants were assessed at baseline and followed up for 2 years. Transition to psychosis and persistence of psychotic symptoms were assessed using the Comprehensive Assessment of At-Risk Mental States criteria. Level of functioning at follow up was assessed using the Global Assessment of Functioning disability scale.

RESULTS

During follow up, 16.2% of the clinical high-risk sample developed psychosis. Of those who did not become psychotic, 51.4% had persistent symptoms and 48.6% were in remission. There was no significant association between any measure of cannabis use at baseline and either transition to psychosis, the persistence of symptoms, or functional outcome.

CONCLUSIONS

These findings contrast with epidemiological data that suggest that cannabis use increases the risk of psychotic disorder.

Cannabis during pregnancy: A way to transfer an impairment to later life

Epidemiological studies examining the influence of cannabis across the lifespan show that exposure to cannabis during gestation or during the perinatal period is associated with later-life mental health issues that manifest during childhood, adolescence, and adulthood. The risk of later-life negative outcomes following early exposure is particularly high in persons who have specific genetic variants, implying that cannabis usage interacts with genetics to heighten mental health risks. Prenatal and perinatal exposure to psychoactive components has been shown in animal research to be associated with long-term effects on neural systems relevant to psychiatric and substance use disorders. The long-term molecular, epigenetic, electrophysiological, and behavioral consequences of prenatal and perinatal exposure to cannabis are discussed in this article. Animal and human studies, as well as in vivo neuroimaging methods, are used to provide insights into the changes induced in the brain by cannabis. Here, based on the literature from both animal models and humans, it can be concluded that prenatal cannabis exposure alters the developmental route of several neuronal regions with correlated functional consequences evidenced as changes in social behavior and executive functions throughout life.

Student perceptions of cannabis use

OBJECTIVE

This qualitative study explored post-secondary students' perceptions of cannabis use on students' health, academic pursuits, and social lives, and investigated how these issues have been impacted by the legalization of recreational cannabis.

Participants: 20 undergraduate students at a small liberal arts university in Atlantic Canada participated in this study.

Methods: Semi-structured interviews were used to learn more about student perceptions of cannabis. Interview transcripts were analyzed using general thematic analysis.

Results: Students in this study report using cannabis in thoughtful ways, balancing various considerations in terms of health, social connections, and academics. They were aware that cannabis is not a risk-free drug and took some steps to manage risks.

Conclusion: Knowing why young adults believe they use cannabis is information for university professionals who want to develop effective harm reduction campaigns.

Subclinical psychotic symptoms in Indian adults: Application of the Community Assessment of Psychic Experiences (CAPE)

BACKGROUND

The study investigated the psychometric properties of the Community, Assessment of Psychic Experiences (CAPE-42), a self-report instrument in Indians.

METHOD

CAPE-42 was translated in Hindi and tested on 312 Indian adults recruited online and through paper-pencil assessment. Confirmatory factor analysis (CFA) was employed to establish the factor structure of the positive, negative and depressive dimensions of CAPE-42: the bifactor model was tested to evaluate whether items converge into a major single factor defining psychotic-proneness in individuals. Latent class analysis (LCA) was conducted to identify subgroups with a different endorsement of subclinical psychotic symptoms.

, RESULTS

CAPE-Hindi showed good reliability (Cronbach's alpha>0.80). CFA confirmed, a good fit for the bifactor model, factor loading was acceptable for all items in the general factor (Omega-h =0.83) and explained the primary variance of the subscales. Residual variance was explained by the positive, negative and depressive factors (Omega H =0.33, 0.04 and 0.12, respectively). LCA identified three classes traceable, to the three dimensions; a low endorsement group (n = 155; 50 %); a less consistent, group with endorsement on positive and depressive items (n = 117; 38 %), and a high, endorsement group (n = 40;13 %).

CONCLUSION

Hindi CAPE-42 showed good reliability and factorial validity.

Profiles and factors associated with schizophrenia in eastern Ethiopia: A matched case-control study

Background

Despite its strong hereditary and genetic connections, there are other factors reported to be linked to schizophrenia, but not well studied in eastern Ethiopia.

Objective

This study was aimed to investigating the potential profiles and factors associated with schizophrenia in eastern Ethiopia.

Materials and methods

A matched case-control study was conducted in two public hospitals from December 1, 2021, to January 30, 2022. Cases were patients with schizophrenia who visited the hospitals, and controls were healthy individuals without any mental illness who visited the same hospitals. A questionnaire was used to collect the data. Cases and controls were matched using age and sex. STATA-14 was used for analysis. A conditional logistic regression with an adjusted odds ratio (AOR) and a 95% confidence interval (CI) was applied to identify the determinants. P-values of <0.05 were used to build the final model as a measure of statistical significance.

Results

The mean age of the study participants group was 28.6 (±8.44) years, mean age for cases was 28.7(±8.5) ranging from 18 to 56 years and the mean age for the controls was 28.4 (±8.5), ranging from 18 to 60 years. About 181 (83.03%) of the participants were male. The odds of having schizophrenia was about 12.2 times higher among participants with family history of mental illness (AOR: 12.21; 95% CI: 4.83-30.00). The odds of having schizophrenia was 4.5 times higher among polysubstance users (AOR: 4.45; 95% CI: 1.28-5.45) and 2.8 times higher among khat consumers (AOR: 2.82; 95% CI: 1.23-6.45) compared to their counterparts.

Conclusion

Our findings show that genetic risk factors as well as some modifiable behaviors are associated to schizophrenia in eastern Ethiopia. At all levels, special attention should be given to those who are at risk.

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.

Adversity in childhood/adolescence and premorbid tobacco, alcohol, and cannabis use among first-episode psychosis patients

AIM

Premorbid substance use is widely recognized as a crucial factor in early psychosis. We explored the effects of childhood/adolescent adversity on premorbid tobacco, alcohol, and cannabis use. We hypothesized that adversity in childhood would be associated with an increased likelihood of use, and amount of intake, of tobacco, alcohol, and cannabis. We analysed which domains of adversity have the greatest impact.

METHODS

First-episode psychosis patients were enrolled from six inpatient psychiatric units in Atlanta, Georgia and Washington, D.C. Premorbid substance use was thoroughly measured, and childhood/adolescent adversity was rated using 14 scales/subscales. Factor analysis was used to reduce these scales/subscales to the three domains of adversity (termed Violence and Environmental Adversity, Interpersonal Abuse, and Neglect and Lack of Connectedness). Regression analyses determined associations between adversity domains and premorbid substance use.

RESULTS

Our sample (n = 247) primarily consisted of African Americans (86.2%) and males (74.5%). Violence and Environmental Adversity was significantly associated with five of six substance use variables and marginally associated with the sixth. Interpersonal Abuse was unassociated with substance use, and Neglect and Lack of Connectedness was associated only with a lower likelihood cannabis use. When Violence and Environmental Adversity results were stratified by gender, effects on tobacco use and amount of tobacco use were stronger among females.

CONCLUSIONS

Childhood/adolescent trauma and adversity have meaningful associations with premorbid substance use in first-episode psychosis patients. First-episode psychosis and clinical high-risk treatment settings may benefit from expanding the assessment of childhood/adolescent adversity to include factors pertaining to violence exposure and adversities beyond abuse and neglect.

Premorbid functioning in schizophrenia spectrum disorders with comorbid substance use: A systematic review

Premorbid functioning has been related with several clinical features and prognosis of schizophrenia spectrum disorders. Comorbidity with substance use is highly prevalent and usually hinders clinical improvement in this kind of psychiatric disorders. This systematic review analyzes the differences in the premorbid functioning of subjects with a schizophrenia spectrum disorder with substance use (SSD+, dual psychosis) or without it (SSD-). A systematic review (PRISMA guidelines), including search in electronic databases (MEDLINE, Web of Science, and Cochrane Library), was performed. 118 published works were considered of which only 20 met our inclusion criteria. Although there is a great variability in methodologies, diagnoses included, and substances used, studies using the Premorbid Functioning Scale to assess the academic and/or social domains found that SSD+ subjects had a poorer academic but better social premorbid functioning than those with SSD-. Current evidence is not conclusive, so additional studies are required to integrate intervening factors in order to clarify the clinical implications of premorbid functioning to improve the course and therapeutic response of patients.

Dissecting Molecular Genetic Mechanisms of 1q21.1 CNV in Neuropsychiatric Disorders

Pathogenic copy number variations (CNVs) contribute to the etiology of neurodevelopmental/neuropsychiatric disorders (NDs). Increased CNV burden has been found to be critically involved in NDs compared with controls in clinical studies. The 1q21.1 CNVs, rare and large chromosomal microduplications and microdeletions, are detected in many patients with NDs. Phenotypes of duplication and deletion appear at the two ends of the spectrum. Microdeletions are predominant in individuals with schizophrenia (SCZ) and microcephaly, whereas microduplications are predominant in individuals with autism spectrum disorder (ASD) and macrocephaly. However, its complexity hinders the discovery of molecular pathways and phenotypic networks. In this review, we summarize the recent genome-wide association studies (GWASs) that have identified candidate genes positively correlated with 1q21.1 CNVs, which are likely to contribute to abnormal phenotypes in carriers. We discuss the clinical data implicated in the 1q21.1 genetic structure that is strongly associated with neurodevelopmental dysfunctions like cognitive impairment and reduced synaptic plasticity. We further present variations reported in the phenotypic severity, genomic penetrance and inheritance.

Longitudinal association between CRP levels and risk of psychosis: a meta-analysis of population-based cohort studies

Meta-analyses of cross-sectional studies suggest that patients with psychosis have higher circulating levels of C-reactive protein (CRP) compared with healthy controls; however, cause and effect is unclear. We examined the prospective association between CRP levels and subsequent risk of developing a psychotic disorder by conducting a systematic review and meta-analysis of population-based cohort studies. Databases were searched for prospective studies of CRP and psychosis. We obtained unpublished results, including adjustment for age, sex, body mass index, smoking, alcohol use, and socioeconomic status and suspected infection (CRP > 10 mg/L). Based on random effect meta-analysis of 89,792 participants (494 incident cases of psychosis at follow-up), the pooled odds ratio (OR) for psychosis for participants with high (>3 mg/L), as compared to low (≤3 mg/L) CRP levels at baseline was 1.50 (95% confidence interval [CI], 1.09-2.07). Evidence for this association remained after adjusting for potential confounders (adjusted OR [aOR] = 1.31; 95% CI, 1.03-1.66). After excluding participants with suspected infection, the OR for psychosis was 1.36 (95% CI, 1.06-1.74), but the association attenuated after controlling for confounders (aOR = 1.23; 95% CI, 0.95-1.60). Using CRP as a continuous variable, the pooled OR for psychosis per standard deviation increase in log(CRP) was 1.11 (95% CI, 0.93-1.34), and this association further attenuated after controlling for confounders (aOR = 1.07; 95% CI, 0.90-1.27) and excluding participants with suspected infection (aOR = 1.07; 95% CI, 0.92-1.24). There was no association using CRP as a categorical variable (low, medium or high). While we provide some evidence of a longitudinal association between high CRP (>3 mg/L) and psychosis, larger studies are required to enable definitive conclusions.

Imaging Brain Fatty Acid Amide Hydrolase in Untreated Patients With Psychosis

BACKGROUND

The brain's endocannabinoid system, the primary target of cannabis, has been implicated in psychosis. The endocannabinoid anandamide is elevated in cerebrospinal fluid of patients with schizophrenia. Fatty acid amide hydrolase (FAAH) controls brain anandamide levels; however, it is unknown if FAAH is altered in vivo in psychosis or related to positive psychotic symptoms.

METHODS

Twenty-seven patients with schizophrenia spectrum disorders and 36 healthy control subjects completed high-resolution positron emission tomography scans with the novel FAAH radioligand [¹¹C]CURB and structural magnetic resonance imaging. Data were analyzed using the validated irreversible 2-tissue compartment model with a metabolite-corrected arterial input function.

RESULTS

FAAH did not differ significantly between patients with psychotic disorders and healthy control subjects (F_1,62.85 = 0.48, p = .49). In contrast, lower FAAH predicted greater positive psychotic symptom severity, with the strongest effect observed for the positive symptom dimension, which includes suspiciousness, delusions, unusual thought content, and hallucinations (F_1,26.69 = 12.42, p = .002; Cohen's f = 0.42, large effect). Shorter duration of illness (F_1,26.95 = 13.78, p = .001; Cohen's f = 0.39, medium to large effect) and duration of untreated psychosis predicted lower FAAH (F_1,26.95 = 6.03, p = .021, Cohen's f = 0.27, medium effect). These results were not explained by past cannabis exposure or current intake of antipsychotic medications. FAAH exhibited marked differences across brain regions (F_7,112.62 = 175.85, p < 1 × 10^-56; Cohen's f > 1). Overall, FAAH was higher in female subjects than in male subjects (F_1,62.84 = 10.05, p = .002; Cohen's f = 0.37).

CONCLUSIONS

This first study of brain FAAH in psychosis indicates that FAAH may represent a biomarker of disease state of potential utility for clinical studies targeting psychotic symptoms or as a novel target for interventions to treat psychotic symptoms.

Persistent cannabis use among young adults with early psychosis receiving coordinated specialty care in the United States

Persistent cannabis use among young adults with first episode psychosis (FEP), even those receiving early intervention services, has been associated with poor outcomes. In the United States (US), Coordinated Specialty Care (CSC) has been shown to be more effective at reducing symptoms, improving quality of life and increasing involvement in work or school, compared to typical care for FEP. However, little is known about the prevalence, course and outcomes for cannabis use in this real-world, clinical setting. This study examined the prevalence, course and outcomes of cannabis use categorized into three groups: no use, reduced use, and persistent use, among a sample of 938 CSC participants enrolled for at least 1 year. Prevalence of cannabis use was 38.8% at admission and 32.8% of the sample had persistent cannabis use at 1 year. At baseline, persistent cannabis users were more likely to be male (p < .001), white, non-Hispanic and black non-Hispanic (p = .001), have worse symptoms as measured by the GAF (p < .001), increased suicidality (p = .024), violent ideation (p = .008), and legal trouble (p = .006) compared with non-users. At 1 year, persistent users maintained worse symptoms compared with non-users (p = .021) while those who reduced use had significant improvement in symptoms compared with persistent users (p = .008). This study suggests that cannabis use is common among young adults enrolled in a CSC program in the US and that persistent cannabis users may have worse outcomes while reducing cannabis use may improve outcomes. These findings highlight the potential impact of secondary prevention in this population through reduction in cannabis use.

A Retrospective Study of the Clinical Characteristics Associated with Alcohol and Cannabis use in Early Phase Psychosis

OBJECTIVE

Alcohol and cannabis misuse are common in patients with early phase psychosis (EPP); however, research has tended to focus primarily on cannabis misuse and EPP outcomes, with a relative lack of data on alcohol misuse. This retrospective cross-sectional EPP study investigated the relationship between cannabis, alcohol, and cannabis combined with alcohol misuse, on age, gender, psychotic, depressive and anxiety symptom severity, and social/occupational functioning, at entry to service.

METHODS

Two-hundred and sixty-four EPP patients were divided into 4 groups based on substance use measured by the Alcohol, Smoking and Substance Involvement Screening Test: (1) no to low-level cannabis and alcohol misuse (LU), (2) moderate to high alcohol misuse only (AU), (3) moderate to high cannabis misuse only (CU), and (4) moderate to high alcohol and cannabis misuse (AU + CU).

RESULTS

We found significant between group differences in age (with the AU group being the oldest and AU + CU group the youngest) as well as gender (with the CU group having the highest percentage of men). There were also group differences in positive psychotic symptoms (lowest in AU group), trait anxiety (highest in AU + CU group), and social/occupational functioning (highest in AU group). Further regression analyses revealed a particularly strong relationship between AU + CU group and trait anxiety (3-fold increased odds of clinical trait anxiety for combined misuse of alcohol and cannabis compared to non/low users).

CONCLUSIONS

This study demonstrates the unique demographic and clinical characteristics found in the EPP population at entry to care associated with alcohol and cannabis misuse both separately and in combination. This work highlights the importance of including the assessment of alcohol misuse in addition to cannabis misuse in future treatment guidelines and research.

Factors Moderating the Association Between Cannabis Use and Psychosis Risk: A Systematic Review

Increasing evidence indicates a relationship between cannabis use and psychosis risk. Specific factors, such as determinants of cannabis use or the genetic profile of cannabis users, appear to moderate this association. The present systematic review presents a detailed and up-to-date literature overview on factors that influence the relationship between cannabis use and psychosis risk. A systematic search was performed according to the PRISMA guidelines in MEDLINE and Embase, and 56 studies were included. The results show that, in particular, frequent cannabis use, especially daily use, and the consumption of high-potency cannabis are associated with a higher risk of developing psychosis. Moreover, several genotypes moderate the impact of cannabis use on psychosis risk, particularly those involved in the dopamine function, such as AKT1. Finally, cannabis use is associated with an earlier psychosis onset and increased risk of transition in individuals at a clinical high risk of psychosis. These findings indicate that changing cannabis use behavior could be a harm reduction strategy employed to lower the risk of developing psychosis. Future research should aim to further develop specific biomarkers and genetic profiles for psychosis, thereby contributing to the identification of individuals at the highest risk of developing a psychotic disorder.

Determining factors for Cannabis use among Moroccans Schizophrenic Patients: A cross sectional study

OBJECTIVE

Cannabis use is considered a major clinical problem associated with a poorer outcome in patients with schizophrenia. The objective of the present study was to assess the prevalence of cannabis us among patients with schizophrenia. The assessment consists in comparing some factors related to substance use in a population of schizophrenic patients between cannabis users and non.

MATERIALS AND METHODS

Four hundred and three participants who were examined prospectively during their hospitalization answered the PANNS scale of schizophrenia, GAF, BIS-10, CDSS, and MARS. The consumption of cannabis was investigated using urine toxicological analysis. Sociodemographic, clinical and therapeutic data were also recorded.

RESULTS

The prevalence of cannabis use among schizophrenic inpatients was 49%. Patients with cannabis use were younger (31.7 vs 34.9 years old, p<0.001), more often male (52 vs 20% female, p<0.001), and they presented more often a history of imprisonment (68.8% vs 31.2%, p<0.001). Patients who were users of cannabis had a lower age at onset of the disease than non-users (23.6 vs 24.8 years, p=0.029), and more often with poor medication adherence (p=0.001). Logistic regression revealed that factors associated with cannabis use among schizophrenics were the age, gender, history of imprisonment and poor medication adherence.

CONCLUSION

The study showed that a high prevalence of cannabis use among patients with schizophrenia which was associated with negative overall outcomes. Determining comorbid substance use disorders among schizophrenic patients is crucial as it may contribute to establish a better therapeutic strategy.

Nicotine consumption during the prodromal phase of schizophrenia - a review of the literature

Recent research has fueled a debate concerning the role of nicotine in the emergence of schizophrenia. The three main hypotheses are: (a) the self-medication effect, (b) the causal relationship hypothesis, or (c) the shared diathesis hypothesis. To explore this role, the study of nicotine consumption during the initial prodromal phase of schizophrenia offers important opportunities. In the present work, 10 relevant studies are reviewed, out of 727 retrieved citations, in order to address questions regarding the prevalence of smoking in the prodromal period, the time of smoking initiation, existing patterns of tobacco use in relation with the escalation of prodromal symptoms into first psychotic episode, and potential differences in symptomatology between smokers and nonsmokers. Even though there was considerable heterogeneity among studies, relevant findings are discussed. Prevalence of nicotine use during the prodromal period was reported to be 16.6-46%. Tobacco use was found to be taken up most often before or during the prodromal period of schizophrenia. Even though a protective role of smoking has been reported by one study, other studies report an increased risk for psychosis, with hazard ratios 2.77 (95% CI: 2.34-3.43) and 2.21 (95% CI: 1.11-4.42) for female and male heavy smokers (11-20 and >20 cigarettes/day), respectively. In a different study, the risk of onset was associated with the progressive use of cannabis and tobacco prior to onset, particularly with rapid escalation to the highest levels of use. Also, nicotine use in ultra high risk (UHR) for developing psychosis subjects is associated with elevated cognitive performance, namely better processing speed, visual learning, and spatial working memory. As a conclusion, it appears that evidence accumulates supporting a possible etiologic role of smoking, in the emergence of schizophrenia along with diverse effects on patients' symptomatology, already demonstrable at the prodromal phase. Future research employing better-defined criteria should further explore the patterns of use and effects of nicotine during the schizophrenia prodrome.

Prenatal THC exposure produces a hyperdopaminergic phenotype rescued by pregnenolone

Increased legal availability of cannabis has led to a common misconception that it is a safe natural remedy for, amongst others, pregnancy-related ailments like morning sickness. Emerging clinical evidence, however, indicates that prenatal cannabis exposure (PCE) predisposes offspring to various neuropsychiatric disorders linked to aberrant dopaminergic function. Yet, our knowledge of how cannabis exposure affects the maturation of this neuromodulatory system remains limited. Here, we show that male, but not female, offspring of Δ⁹-tetrahydrocannabinol (THC)-exposed dams, a rat PCE model, exhibit extensive molecular and synaptic changes in dopaminergic neurons of the ventral tegmental area, including altered excitatory-to-inhibitory balance and switched polarity of long-term synaptic plasticity. The resulting hyperdopaminergic state leads to increased behavioral sensitivity to acute THC during pre-adolescence. The FDA-approved neurosteroid pregnenolone rescues synaptic defects and normalizes dopaminergic activity and behavior in PCE offspring, suggesting a therapeutic approach for offspring exposed to cannabis during pregnancy.

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.

Trend level gene-gender interaction effect for the BDNF rs6265 variant on age of onset of psychosis

A BDNF rs6265 [A/A] by gender by cannabis use interaction has been associated with age of onset of psychosis (AoP). We examined the gender and cannabis use-adjusted association between BDNF rs6265 [G>A] and AKT1 rs2494732 [T>C] and AoP. Data from 167 Caucasians on AoP and age at first regular cannabis use were collected. Kaplan-Meier and Cox regression analyses were conducted. A trend level gene-gender interaction effect was observed for the BDNF rs6265 A/A genotype, controlling for age at first regular cannabis use. Larger collaborative research projects are required to further investigate this effect.

Factor structure of the Cannabis Experiences Questionnaire in a first-episode psychosis sample

AIM

The Cannabis Experiences Questionnaire (CEQ) was developed to measure the subjective experiences of cannabis use both during and after intoxication. Despite the need to better understand the nature of the complex and significant relationship between cannabis use and early psychosis, this questionnaire has rarely been used in individuals with first-episode psychosis.

METHODS

We conducted a set of factor analyses using CEQ data from 194 first-episode psychosis patients who used cannabis in order to uncover the underlying factor structure of the questionnaire and thus the overarching types of psychological experiences during/after using cannabis in young people with psychotic disorders.

RESULTS

Our exploratory factor analysis identified 4 subscales, including: Distortions of Reality and Self-Perception (Factor 1), Euphoria Effects (Factor 2), Slowing and Amotivational Effects (Factor 3), and Anxiety and Paranoia Effects (Factor 4).

CONCLUSIONS

Elucidating the underlying factor structure of the CEQ in first-episode psychosis samples could help researchers move towards a deeper understanding of the types of experiences associated with cannabis intoxication among young adults with first-episode psychosis and could inform the development of programs designed to reduce use, improve the course of illness, and possibly delay or prevent the onset of psychotic symptoms in those at risk.

Cannabis Use: Neurobiological, Behavioral, and Sex/Gender Considerations

PURPOSE OF REVIEW

To summarize the current literature on the effects of cannabinoids in humans and to discuss the existing literature on the sex- and gender-related differences in the effects of cannabinoids.

RECENT FINDINGS

Cannabis and its constituent cannabinoids are associated with risk of addiction, cognitive deficits and mood/psychotic disorders. Preclinical and emerging clinical data suggest greater sensitivity to the effects of cannabinoids in women.

SUMMARY

Cannabis is one of the most commonly used drugs with increasing rates of use. Women in particular may be at a greater risk of adverse outcomes given the previously described "telescoping effect" of substance use in women. Human data examining the sex- and gender-related differences in the effects of cannabinoids and factors underlying these differences are very limited. This represents a critical gap in the literature and needs to be systematically examined in future studies.

Comorbid Cannabis and Tobacco Use Disorders in Hospitalized Patients with Psychotic-Spectrum Disorders

OBJECTIVE

Individuals with psychotic-spectrum disorders use tobacco and cannabis at higher rates than the general population and individuals with other psychiatric disorders, which may contribute to increased rates of medical problems and mortality. The present study examined whether individuals with psychosis and comorbid tobacco and/or cannabis use disorders exhibit differing clinical characteristics in terms of their sociodemographic, mental health, substance use, physical health, and medication use patterns. Elucidation of these profiles, and determining their relative severity, has important implications for treatment, including offering more targeted interventions based on type of comorbidity pattern.

METHODS

We examined the electronic medical records of 829 patients with psychotic-spectrum disorders admitted to a psychiatric hospital and categorized them as having: (1) cannabis use disorder (CUD); (2) tobacco use disorder (TUD); (3) comorbid cannabis and tobacco use disorders (CUD + TUD); or (4) neither disorder (no CUD/TUD). Multinomial logistic regression was used to compare the aforementioned groups on multiple variables controlling for age and sex.

RESULTS

Alcohol and stimulant use disorder diagnoses were each related to higher odds of having a CUD and CUD + TUD, relative to no CUD/TUD. Stimulant and polysubstance use disorder diagnoses were each related to higher odds of having a TUD compared to no CUD/TUD. Greater number of prescribed psychotropic medications was related to higher odds of a TUD compared to no CUD/TUD.

CONCLUSIONS

Although several differences between groups were accounted for by age of cannabis versus tobacco users, findings point to the importance of considering comorbid alcohol and substance use disorders among those with psychosis and CUD/TUD, as these comorbidities have important implications for screening and treatment selection during and following acute hospitalization.

Demographic and socioenvironmental predictors of premorbid marijuana use among patients with first-episode psychosis

OBJECTIVE

We identified, in subjects with first-episode psychosis, demographic and socioenvironmental predictors of three variables pertaining to premorbid marijuana use: age at initiation of marijuana use, trajectories of marijuana use in the five years prior to onset of psychosis, and the cumulative "dose" of marijuana intake in that same premorbid period.

METHODS

We enrolled 247 first-episode psychosis patients and collected data on lifetime marijuana/alcohol/tobacco use, age at onset of psychosis, diverse socioenvironmental variables, premorbid adjustment, past traumatic experiences, perceived neighborhood-level social disorder, and cannabis use experiences. Bivariate tests were used to examine associations between the three premorbid marijuana use variables and hypothesized predictors. Regression models determined which variables remained independently significantly associated.

RESULTS

Age at initiation of cigarette smoking was linked to earlier initiation, faster escalation, and higher cumulative dose of premorbid marijuana use. During childhood, poorer academic performance was predictive of an earlier age at initiation of marijuana use, while poorer sociability was related to more rapid escalation to daily use and a higher cumulative dose. As expected, experiencing euphoric effects was positively correlated with trajectories and cumulative dose, but having negative experiences was unrelated. Traumatic childhood/adolescent experiences were correlated with rapid escalation and amount of marijuana used, but not with age at initiation of marijuana use.

CONCLUSION

These data expand the very limited literature on predictors of premorbid marijuana use in first-episode psychosis. Given its association with earlier age at onset of psychosis, and poorer outcomes among first-episode patients, prevention and treatment efforts should be further developed.

Patterns in adolescent cannabis use predict the onset and symptom structure of schizophrenia-spectrum disorder

This study investigated adolescent cannabis use as a risk factor for schizophrenia spectrum disorder (SSD). Motives for early cannabis use and resulting usage patterns were examined alongside clinical measures of SSD onset and symptomatology. Participants (N = 178) were recruited for two samples, 1: healthy controls (HC) with cannabis use, 2: schizophrenia patients (SSD) with cannabis use. Structured interviews of participants and family informants were used to obtain diagnostic and biographical information. Factor-analysis of reported motives for initiating cannabis use produced four groups; sedation, stimulation, social pressure, and recreation. Regression analyses revealed significant relationships between these groups and SSD. Most notably, reason group factor scores predict SSD risk as well as schizotypal symptom severity. Findings also indicate that these factors follow a hierarchical structure, which explains their relative involvement in increased SSD risk. We suggest that adolescent cannabis use both hastens the onset and amplifies the severity of SSD. In response we propose a model for identifying at risk individuals, predicting the onset and severity of SSD, and potentially mitigating the associated psychiatric impairments.

Addiction Vulnerability: Exploring Relationships Among Cigarette Smoking, Substance Misuse, and Early Psychosis

OBJECTIVE

Smoking rates in adolescents at risk for psychosis are significantly greater than in those who are not at risk. Recent research suggests that cigarette smoking in adolescence may be a potential marker of transition to psychosis, although the exact relationship between the two remains unclear. Our aim was to examine whether tobacco smoking is a potential marker of transition to psychosis or subsequent episodes of psychosis, independently of other substance use, or alternatively whether smoking is essentially a general marker of later mental illness episodes.

METHODS

This substudy was conducted as part of an audit of a specialized early psychosis community mental health service, the Psychological Assistance Service (PAS). A multilayered audit over 10 years (January 1997 to December 2007) of PAS presentations was conducted (N = 1997), which documented baseline sociodemographic and clinical characteristics and subsequent illness episodes and service usage. Among clients with baseline smoking status information (n = 421, mean age = 18.3 years), this study examined predictors of transition to or subsequent episodes of psychosis, substance misuse, and affective disorder.

RESULTS

A recent psychosis episode at baseline and receiving ongoing treatment from PAS predicted transition to or subsequent psychosis episodes; however, baseline ultra-high-risk status was not predictive. In addition, baseline smoking/substance misuse status was a significant predictor, with smokers being twice as likely to experience a subsequent episode of psychosis, even after controlling for other baseline comorbidity. Baseline smoking status also independently predicted subsequent substance misuse episodes, but not subsequent affective disorder. Among clients experiencing post-PAS comorbid substance misuse and psychosis, the majority (80.3%) reported smoking at baseline.

CONCLUSIONS

Smoking status at service presentation appeared to function as a general proxy for addiction vulnerability among young help seekers and thereby as a potential marker for the development of severe mental illness (including psychosis) and associated health problems. Routine evaluations of presenting problems need to incorporate comprehensive assessments of early substance misuse and tobacco smoking. Adjunctive lifestyle interventions promoting smoking cessation, physical health, and well-being need to be offered in conjunction with conventional mental health interventions tailored to key presenting problems, recovery, and psychological strengthening.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cannabis, a Significant Risk Factor for Violent Behavior in the Early Phase Psychosis. Two Patterns of Interaction of Factors Increase the Risk of Violent Behavior: Cannabis Use Disorder and Impulsivity; Cannabis Use Disorder, Lack of Insight and Treatment Adherence

Background: Previous literature suggests that prevalence of cannabis use in the early phase of psychosis is high, and that early psychosis patients are at high-risk for violent behavior. However, the link between cannabis use and violent behavior in early psychosis patients is unclear. We carried out a study on a sample of early psychosis patients, in order to explore the impact of cannabis use on the risk of violent behavior (VB), while taking into account (1) potential confounding factors and, (2) interactions with other dynamic risk factors of VB. Method: In a sample of 265 early psychosis patients, treated at the Treatment and Early Intervention in Psychosis Program (TIPP) in Lausanne, we used logistic regression models to explore the link between various dynamic risk factors of VB [positive symptoms, substance use disorder (drugs including cannabis, alcohol and others drugs), insight, impulsivity, affective instability, and treatment adherence], and VB occurring during treatment. In order to understand hierarchical effects attributable to the combinations of risk factors on VB we conducted a Classification and Regression Tree (CART). Results: Our results show that cannabis use disorder is a risk factor for VB. The associations among risk factors suggest the presence of two patient profiles with an increased rate of VB: the first is composed of patients with cannabis use disorder and impulsivity, and the second of patients combining cannabis use disorder, absence of insight and non-adherence to treatment. The results also show the moderating role of insight and adherence to treatment on the rate of VB in patients with cannabis use disorder. Conclusion: This study suggests that cannabis use disorder is a significant risk factor for VB amongst early psychosis patients, particularly when combined with either impulsivity, lack of insight and non-adherence to treatment. These results suggest that preventive strategies could be developed on the basis of such patient profiles.

Investigation of the COMT Val158Met variant association with age of onset of psychosis, adjusting for cannabis use

OBJECTIVE

COMT rs4680 (Val158Met) genotype moderates the effect of cannabis on the age of onset of psychosis (AoP). We investigated the association between rs4680 and AoP, after adjusting for relevant covariates, in a Canadian Caucasian sample.

METHODS

One hundred and sixty-nine subjects with psychosis were recruited. AoP, defined as age of DSM-IV diagnosis was established using the Structured Clinical Interview for DSM-IV. Cannabis use data were collected using a self-report computerized questionnaire. DNA was extracted from saliva and genotyping of the COMT Val158Met polymorphism was done by SNaPshot and TaqMan assays. Kaplan-Meier analysis results are reported.

RESULTS

In those who had used cannabis before 20 years of age, rs4680 had a trend level effect on AoP (median AoP: Val/Val < Val/Met < Met/Met 19.37, 20.95, 21.24 years, respectively; log-rank test p = .051).

CONCLUSION

Our data are indicative of the need to further investigate the association between the COMT rs4680 variant and AoP in the context of adolescent cannabis use.

Cannabis use in male and female first episode of non-affective psychosis patients: Long-term clinical, neuropsychological and functional differences

BACKGROUND

Numerous studies show the existence of a high prevalence of cannabis use among patients with psychosis. However, the differences between men and women who debut with a first episode of psychosis (FEP) regarding cannabis use have not been largely explored. The aim of this study was to identify the specific sex factors and differences in clinical evolution associated with cannabis use.

METHOD

Sociodemographic characteristics at baseline were considered in our sample of FEP patients to find differences depending on sex and the use of cannabis. Clinical, functional and neurocognitive variables at baseline, 1-year, and 3-years follow-up were also explored.

RESULTS

A total of 549 patients, of whom 43% (N = 236) were cannabis users, 79% (N = 186) male and 21% (N = 50) female, were included in the study. There was a clear relationship between being male and being a user of cannabis (OR = 5.6). Cannabis users were younger at illness onset. Longitudinal analysis showed that women significantly improved in all three dimensions of psychotic symptoms, both in the subgroup of cannabis users and in the non-users subgroup. Conversely, subgroups of men did not show improvement in the negative dimension. In cognitive function, only men presented a significant time by group interaction in processing speed, showing a greater improvement in the subgroup of cannabis users.

CONCLUSION

Despite knowing that there is a relationship between cannabis use and psychosis, due to the high prevalence of cannabis use among male FEP patients, the results showed that there were very few differences in clinical and neurocognitive outcomes between men and women who used cannabis at the start of treatment compared to those who did not.

Substance abuse and gender differences in first episode psychosis: Impact on hospital readmissions

INTRODUCTION

There have been controversial results in the study of gender differences in first episode psychosis (FEP). Substance abuse is the main existing comorbidity in FEP, and has been associated with worse prognosis and greater symptom severity.

OBJECTIVES

To explore gender differences in FEP in relation to drug abuse, and their relationship with hospital readmissions.

METHODOLOGY

Descriptive and prospective study (18 months).

RESULTS

We included 141 patients (31.2% women), aged 26.1 years on average, mostly diagnosed with schizophreniform disorder (32.6%). A percentage of 58.9 had problematic use of drugs. Gender significant differences were found in age of onset, age at entry to the programme, marital status and cohabitation, and percentage differences were revealed in current drug abuse and frequency of consumption. Gender, duration of untreated psychosis, psychiatric history, age of onset and previous drug use were not predictors of re-entry. Hospital readmission rate was 24.8%, with no gender differences. The most common reasons for admission were abandonment of treatment (66.7%) and drug abuse (44.4%). Drug abuse was higher in the men than in the women as a reason for re-admission.

CONCLUSIONS

There are gender differences in FEP. Men have an earlier onset of symptoms and have worse functional outcomes. Drug abuse in men is higher and represents a major cause of hospital readmission. Therapeutic interventions to prevent the effects of drug abuse are necessary from the early stages of the illness.

Cannabis-associated psychosis: Neural substrate and clinical impact

Prospective epidemiological studies have consistently demonstrated that cannabis use is associated with an increased subsequent risk of both psychotic symptoms and schizophrenia-like psychoses. Early onset of use, daily use of high-potency cannabis, and synthetic cannabinoids carry the greatest risk. The risk-increasing effects are not explained by shared genetic predisposition between schizophrenia and cannabis use. Experimental studies in healthy humans show that cannabis and its active ingredient, delta-9-tetrahydrocannabinol (THC), can produce transient, dose-dependent, psychotic symptoms, as well as an array of psychosis-relevant behavioral, cognitive and psychophysiological effects; the psychotogenic effects can be ameliorated by cannabidiol (CBD). Findings from structural imaging studies in cannabis users have been inconsistent but functional MRI studies have linked the psychotomimetic and cognitive effects of THC to activation in brain regions implicated in psychosis. Human PET studies have shown that acute administration of THC weakly releases dopamine in the striatum but that chronic users are characterised by low striatal dopamine. We are beginning to understand how cannabis use impacts on the endocannabinoid system but there is much still to learn about the biological mechanisms underlying how cannabis increases risk of psychosis. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".

Attenuated Positive Psychotic Symptoms in Relation to Cigarette Smoking in a Nonclinical Population

INTRODUCTION

This study explored the association between cigarette smoking and attenuated positive psychotic symptoms in a young adult nonclinical sample.

METHODS

Undergraduates (N = 930), aged 18-35 years (26.3% male), completed a battery of self-report measures assessing subthreshold psychotic symptoms, cigarette smoking behavior/dependence, and drug use.

RESULTS

Individuals endorsing a greater number of attenuated positive psychotic symptoms were more likely to be smokers. Exploratory analyses indicated that the odds of being a smoker were two times greater for those at potential higher risk for psychosis compared with individuals at lower risk. Results were consistent after adjusting for sex and other drug use.

CONCLUSIONS

In line with findings from psychotic populations, results suggest that attenuated positive psychotic symptoms, particularly those endorsed as distressing in a nonclinical, undergraduate population, are related to cigarette smoking.

IMPLICATIONS

Even in nonclinical, undergraduate populations, subthreshold psychotic symptoms are related to cigarette smoking, and cigarette smokers are twice as likely to be considered at potentially higher risk for psychosis compared with noncigarette smokers. In summary, there may be a threshold whereby psychotic symptoms confer increased risk for nicotine consumption, with endorsement of a greater number of distressing subthreshold psychotic symptoms increasing the likelihood of cigarette use.

Cannabis use related to early psychotic onset: Role of premorbid function

The present cross-sectional study investigates the relation between Cannabis and the development of a psychotic disorder. The main objective is to explore the relations between Cannabis use and psychosis onset, premorbid adjustment cognitive impairment and familiarity. Forty-three patients with a diagnosis of Psychotic Disorder were recruited and divided in two groups based on Cannabis use before onset: Cannabis-using patients (PCU, N=21) and Cannabis-free patients (PCF, N=22). Cognitive functioning was evaluated by Trail Making Test A and B (TMT), Rey-Osterrieth Complex Figure Test (ROCF), and the Rey Auditory-Verbal Learning Test (RAVLT). Premorbid functioning was assessed retrospectively through the Premorbid Adjustment Scale (PAS). PCU group showed earlier onset of the psychotic disorder compared to PCF (p=0.008). This finding was not influenced by age or positive family history for psychiatric illness. PCU subjects showed a worse premorbid functioning respect to PCF and this difference was found to impact on the early onset in the PCU group. In conclusion the present study suggests the hypothesis of an interactive role of Cannabis and poor premorbid school adjustment in the development of psychotic disorders.

Cannabis and development of dual diagnoses: A literature review

BACKGROUND

The use of cannabis has garnered more attention recently with ongoing efforts at marijuana legalization. The consequences of cannabis use are not clearly understood and remain a concern.

OBJECTIVES

To review the acute and persistent effects of cannabis use and associations with psychiatric disorders.

METHODS

Using Pubmed and PsychInfo, we conducted a narrative review of the literature on cannabis and psychiatric comorbidity using the keywords cannab*, marijuana, schizo*, psychosis, mood, depression, mania, bipolar, and anxiety.

RESULTS

There is substantial evidence of cannabis use leading to other illicit drug use and of an association between cannabis use and psychosis. A few reports suggest an association with bipolar disorder while the association with depression and anxiety disorders is mixed.

CONCLUSIONS

Whenever an association is observed between cannabis use and psychiatric disorders, the relationship is generally an adverse one. Age at the time of cannabis use appears to be an important factor with stronger associations observed between adolescent onset cannabis use and later onset of psychiatric disorders. Additional studies taking into account potential confounds (such as withdrawal symptoms, periods of abstinence, and other substance use) and moderators (such as age of initiation of cannabis use, the amount and frequency of drug use, prior history of childhood maltreatment, and gender) are needed to better understand the psychiatric consequences of cannabis use.

Differential effects of sex on substance use between first episode psychosis patients and healthy people

BACKGROUND

Substance use in psychosis is an important field of study given that it can be a risk factor for the development of psychosis and can give rise to psychotic symptoms. Studies of substance use in first episode psychosis patients do not frequently assess non-pathological substance consumption among patients, but rather the prevalence of substance abuse or dependence disorders. Moreover, most of these studies do not address the effects of sex in sufficient depth, and the consumption of caffeine or tobacco, which are two of the most frequently used substances, is often not assessed.

OBJECTIVES

The aim of this study was to compare patterns and quantities of substance use between first episode psychosis patients and healthy controls and between men and women, and explore the potential interactive effects between group (patients or controls) and sex.

METHODS

A total of 158 participants (82 first episode psychosis patients and 76 healthy controls) were included in the study. Both adults and adolescents were included in the study. Frequency and amount of use of caffeine, tobacco, alcohol, cannabis, cocaine, hallucinogens, stimulants, and opiates were gathered.

RESULTS

A significant main effect of sex was found for the frequency of use of tobacco (p=.050). Main effects of group were found for the quantity of tobacco (p<.001) and cannabis (p<.001) consumed, as well as main effects of sex for the quantity of alcohol (p=.003) and cannabis (p=.017) consumed. There were also interaction effects between group and sex for the frequency of use of tobacco (p=.005) and cannabis (p=.009), and for the amount of cannabis consumed (p=.049). Qualitative differences between males and females regarding combined substance use are also reported.

CONCLUSIONS

Among patients, men used tobacco more frequently than women, but this sex difference was not the same for the control group, in which women smoked more often than men. Regarding cannabis, men smoked cannabis more frequently and in larger amounts than women, but only in the patients group, whereas no sex differences for cannabis were found for the controls. Main effects of group and sex for tobacco and alcohol, as well as the lack of differences for the frequency and amount of use of caffeine, are also commented. This is the first study to assess the different effects of sex on substance use in first episode psychosis patients and healthy controls.

Evidence for an agitated-aggressive syndrome in early-onset psychosis correlated with antisocial personality disorder, forensic history, and substance use disorder

OBJECTIVE

Agitation, aggression, and violence are increased in psychotic disorders. Additionally, an earlier age at onset may be associated with aggressive behavior. However, the relationship of age at onset, an agitated-aggressive syndrome as measured with the Positive And Negative Syndrome Scale for Schizophrenia - Excited Component (PANSS-EC), and its potential correlates in first-episode psychosis (FEP) has not been studied.

METHOD

This study assessed the association between age at onset, an agitated-aggressive syndrome, and its potential correlates in a prospective sample of 52 FEP patients with early-onset and adult-onset followed up for 12months.

RESULTS

Twenty-six patients conformed to the criteria of early-onset psychosis. Early age at onset was associated with antisocial personality disorder (p=0.004; φc=0.39), a history of legal involvement (p=0.005; φc=0.39), and higher rates of lifetime substance use disorder (SUD; p=0.002; φc=0.42). Early-onset patients had significantly higher PANSS-EC scores over the course of observation (F(1,44.4)=5.39; p=0.025; d=0.656), but no significant group differences emerged for the remaining PANSS subscores. PANSS-EC scores were correlated positively with antisocial personality disorder and forensic history at 6weeks, 3months, 6months, and 12months, and with lifetime substance use disorder at 3months and 6months.

CONCLUSIONS

Patients with early onset psychosis may have increased levels of agitation/aggressiveness, and, more likely, antisocial personality disorder, forensic history, and lifetime substance use disorder. These variables were linked to suicidality, aggressiveness, and involuntary treatment.

The Role of Endocannabinoid Signaling in Cortical Inhibitory Neuron Dysfunction in Schizophrenia

Cannabis use has been reported to increase the risk of developing schizophrenia and to worsen symptoms of the illness. Both of these outcomes might be attributable to the disruption by cannabis of the endogenous cannabinoid system's spatiotemporal regulation of the inhibitory circuitry in the prefrontal cortex that is essential for core cognitive processes, such as working memory, which are impaired in schizophrenia. In the healthy brain, the endocannabinoid 2-arachidonylglycerol 1) is synthesized by diacylglycerol lipase in pyramidal neurons; 2) travels retrogradely to nearby inhibitory axon terminals that express the primary type 1 cannabinoid receptor (CB1R); 3) binds to CB1R, which inhibits gamma-aminobutyric acid release from the cholecystokinin-containing population of interneurons; and 4) is metabolized by either monoglyceride lipase, which is located in the inhibitory axon terminal, or by α-β-hydrolase domain 6, which is co-localized presynaptically with diacylglycerol lipase. Investigations of the endogenous cannabinoid system in the prefrontal cortex of subjects with schizophrenia have found evidence of higher metabolism of 2-arachidonylglycerol, as well as both greater CB1R receptor binding and lower levels of CB1R messenger RNA and protein. Current views on the potential pathogenesis of these alterations, including disturbances in the development of the endogenous cannabinoid system, are discussed. In addition, how interactions between these alterations in the endocannabinoid system and those in other inhibitory neurons in the prefrontal cortex in subjects with schizophrenia might increase the liability to adverse outcomes with cannabis use is considered.

Marijuana use in the immediate 5-year premorbid period is associated with increased risk of onset of schizophrenia and related psychotic disorders

OBJECTIVES

Several studies suggest that adolescent marijuana use predicts earlier age at onset of schizophrenia, which is a crucial prognostic indicator. Yet, many investigations have not adequately established a clear temporal relationship between the use and onset.

METHODS

We enrolled 247 first-episode psychosis patients from six psychiatric units and collected data on lifetime marijuana/alcohol/tobacco use, and ages at onset of prodrome and psychosis in 210 of these patients. Cox regression (survival analysis) was employed to quantify hazard ratios (HRs) for effects of diverse premorbid use variables on psychosis onset.

RESULTS

Escalation of premorbid use in the 5years prior to onset was highly predictive of an increased risk for onset (e.g., increasing from no use to daily use, HR=3.6, p<0.0005). Through the analysis of time-specific measures, we determined that daily use approximately doubled the rate of onset (HR=2.2, p<0.0005), even after controlling for simultaneous alcohol/tobacco use. Building on previous studies, we were able to determine that cumulative marijuana exposure was associated with an increased rate of onset of psychosis (p=0.007), independent of gender and family history, and this is possibly the reason for age at initiation of marijuana use also being associated with rate of onset in this cohort.

CONCLUSIONS

These data provide evidence of a clear temporal relationship between escalations in use in the five years pre-onset and an increased rate of onset, demonstrate that the strength of the association is similar pre- and post-onset of prodromal symptoms, and determine that early adult use may be just as important as adolescent use in these associations.

Utility of Washington Early Recognition Center Self-Report Screening Questionnaires in the Assessment of Patients with Schizophrenia and Bipolar Disorder

Early identification and treatment are associated with improved outcomes in bipolar disorder (BPD) and schizophrenia (SCZ). Screening for the presence of these disorders usually involves time-intensive interviews that may not be practical in settings where mental health providers are limited. Thus, individuals at earlier stages of illness are often not identified. The Washington Early Recognition Center Affectivity and Psychosis (WERCAP) screen is a self-report questionnaire originally developed to identify clinical risk for developing bipolar or psychotic disorders. The goal of the current study was to investigate the utility of the WERCAP Screen and two complementary questionnaires, the WERC Stress Screen and the WERC Substance Screen, in identifying individuals with established SCZ or BPD. Participants consisted of 35 BPD and 34 SCZ patients, as well as 32 controls (CON), aged 18-30 years. Univariate analyses were used to test for score differences between groups. Logistic regression and receiver operating characteristic (ROC) curves were used to identify diagnostic predictors. Significant group differences were found for the psychosis section of the WERCAP (pWERCAP; p < 0.001), affective section of the WERCAP (aWERCAP; p = 0.001), and stress severity (p = 0.027). No significant group differences were found in the rates of substance use as measured by the WERC Substance Screen (p = 0.267). Only the aWERCAP and pWERCAP scores were useful predictors of diagnostic category. ROC curve analysis showed the optimal cut point on the aWERCAP to identify BPD among our participant groups was a score of >20 [area under the curve (AUC): 0.87; sensitivity: 0.91; specificity: 0.71], while that for the pWERCAP to identify SCZ was a score of >13 (AUC: 0.89; sensitivity: 0.88; specificity: 0.82). These results indicate that the WERCAP Screen may be useful in screening individuals for BPD and SCZ and that identifying stress and substance-use severity can be rapidly done using self-report questionnaires. Larger studies in undiagnosed individuals will be needed to test the WERCAP Screen's ability to identify mania or psychosis in the community.

Prescription stimulant use is associated with earlier onset of psychosis

A childhood history of attention deficit hyperactivity disorder (ADHD) is common in psychotic disorders, yet prescription stimulants may interact adversely with the physiology of these disorders. Specifically, exposure to stimulants leads to long-term increases in dopamine release. We therefore hypothesized that individuals with psychotic disorders previously exposed to prescription stimulants will have an earlier onset of psychosis. Age of onset of psychosis (AOP) was compared in individuals with and without prior exposure to prescription stimulants while controlling for potential confounding factors. In a sample of 205 patients recruited from an inpatient psychiatric unit, 40% (n = 82) reported use of stimulants prior to the onset of psychosis. Most participants were prescribed stimulants during childhood or adolescence for a diagnosis of ADHD. AOP was significantly earlier in those exposed to stimulants (20.5 vs. 24.6 years stimulants vs. no stimulants, p < 0.001). After controlling for gender, IQ, educational attainment, lifetime history of a cannabis use disorder or other drugs of abuse, and family history of a first-degree relative with psychosis, the association between stimulant exposure and earlier AOP remained significant. There was a significant gender × stimulant interaction with a greater reduction in AOP for females, whereas the smaller effect of stimulant use on AOP in males did not reach statistical significance. In conclusion, individuals with psychotic disorders exposed to prescription stimulants had an earlier onset of psychosis, and this relationship did not appear to be mediated by IQ or cannabis.

Racial disparities during admission to an academic psychiatric hospital in a large urban area

Multiple studies confirm that African Americans are less likely than non-Hispanic whites to receive needed mental health services. Research has consistently shown that African Americans are under-represented in outpatient mental health treatment settings and are over-represented in inpatient psychiatric settings. Further, African Americans are more likely to receive a diagnosis of schizophrenia and are less likely receive an affective disorder diagnosis during inpatient psychiatric hospitalization compared to non-Hispanic white patients, pointing to a need for examining factors contributing to mental health disparities. Using Andersen's Behavioral Model of Health Service Use, this study examined predisposing, enabling and need factors differentially associated with health service utilization among African American and non-Hispanic white patients (n=5183) during psychiatric admission. We conducted univariate and multivariate logistic regression analyses to examine both main effects and interactions. In the multivariate model, African American race at admission was predicted by multiple factors including younger age, female gender, multiple psychiatric hospitalizations, elevated positive and negative symptoms of psychosis, a diagnosis of schizophrenia and substance use, as well as having housing and commercial insurance. Additionally, screening positive for cannabis use at intake was found to moderate the relationship between being female and African American. Our study findings highlight the importance of examining mental health disparities using a conceptual framework developed for vulnerable populations (such as racial minorities and patients with co-occurring substance use).

Responses to Tobacco Smoking-Related Health Messages in Young People With Recent-Onset Schizophrenia

Virtually no research has examined the responses of youth with recent-onset psychosis (ROP) to smoking-related health warnings. We examined predictors of response and tested hypotheses that participants with ROP would (a) assess warnings as less effective than a healthy comparison (HC) group, and (b) assess video warnings as more effective than pictures. ROP participants (n = 69) had <2 years of prior antipsychotic treatment; the HC group (n = 79) had no major mental illness. Participants viewed 10 pictorial warnings, 8 videos depicting similar messages, and were interviewed regarding tobacco use, health literacy, and smoking knowledge. We assessed response at baseline and at 4-week follow-up. ROP participants were more likely than HC to smoke tobacco (49.3% vs 10.1%) and had lower levels of health literacy and smoking-related knowledge. Cannabis was used by 46.4% of ROP participants. Effectiveness ratings were high for both picture and video warnings with no differences between media. ROP participants compared to HC and nonsmokers compared to smokers were more likely to perceive warnings as effective. Effectiveness was associated with negative affect and greater emotional arousal. We assessed 33 smokers at follow-up; 5 (15%) identified as nonsmokers, 15 (45%) made a quit attempt, and 16 (49%) reported that the warnings influenced their smoking. Results indicate that young people with psychotic disorders respond favorably to health warnings. Effective messages depict health consequences clearly, elicit negative emotions, and may impact smoking behavior. Future research is needed to understand the effects of mode of presentation and message comprehension on smoking behavior.

Relationship between cannabis and psychosis: Reasons for use and associated clinical variables

The mechanism underneath the relationship between cannabis and psychosis remains controversial, for which several hypotheses have been proposed, including cannabis as self-medication and cannabis as a risk for the development of psychosis. The aim of this work was to study the relationship between cannabis and psychosis in first-episode psychosis cannabis users and non-users, and non-psychotic cannabis users. The age at the first psychotic episode, duration of untreated psychosis, psychopathology and reasons for cannabis use were assessed. First-episode psychosis cannabis users showed an earlier age at psychosis onset than non-user patients. No significant differences in symptomatology were found. The distinguishing reasons to use cannabis for patients with first-episode psychosis with respect to non-psychotic users were to arrange their thoughts and deal with hallucinations and suspiciousness. These findings are in agreement with both hypotheses: self-medication and secondary psychosis hypothesis. However, longitudinal prospective cohort studies assessing reasons for cannabis use are needed to investigate both hypotheses and their complementarity.