The interaction of gender and cannabis in early phase psychosis

Gender differences in first episode psychosis: Some arguments to develop gender specific treatment strategies

INTRODUCTION

Some aspects of gender differences in patients with schizophrenia spectrum disorders (SSD) have been studied, especially in cross-sectional designs and with a short-term follow-up. However, only a few studies have considered the evolution during the follow-up of SSD patients according to their gender. In this study, we explore gender differences from the time of entry in an early intervention program for psychosis, up to three years follow-up.

METHODS

We conducted a prospective study including a cohort of 474 patients treated at the Treatment and Early Intervention in Psychosis (TIPP) program, 319 men and 155 women, having presented a first episode of psychosis (FEP). Data regarding premorbid and baseline sociodemographic, psychopathological and patient functioning, were collected. These data were reassessed longitudinally after 2, 6, 12, 18, 24, 30 and 36 months after entry in TIPP.

RESULTS

Regarding premorbid and baseline characteristics, woman developed threshold symptoms of a FEP 1 year later than men on average. Women were more likely to be married, men were more likely to live in pension or care home facility or to be homeless. Women displayed a higher rate of history of suicide attempts and exposure to childhood trauma, while men were more likely to have a forensic history, a history of abuse of alcohol and cannabis as well as a dependency to cannabis at the time of entry in TIPP. Regarding evolution, men were more prone to violent acts and were less likely to decrease their usage of substances. The longitudinal analysis highlighted that men displayed greater negative symptoms over the entire treatment period, lower functioning after 6 months and on all assessment points after. Both genders displayed similar rate of improvement in these 3 dimensions over time.

CONCLUSION

Our study confirms that there are some gender differences in the early phase of psychosis that may require differentiation of assessment and treatment to improve recovery.

Effects of sexual assault vs. other traumatic experiences on emotional and cannabis use outcomes in regular cannabis users with trauma histories: moderation by gender?

Introduction

While sexual assault may have particularly adverse emotional effects compared with other forms of trauma, it remains unclear which emotional outcome dimensions are impacted, whether cannabis outcomes are similarly impacted, and whether gender differences exist in sexual assault's links with these outcomes.

Methods

N = 100 cannabis users with trauma histories (M age = 33.1) completed standardized measures of demographics, trauma exposure, posttraumatic stress (PTS) and depressive symptoms, hopelessness, and cannabis outcomes (frequency, medicinal prescription, motives, and craving).

Results

Sexual assault was experienced more often by women (83.9%) than men (31.8%). A series of 2 × 2 analyses of variance [gender: women (n = 56) vs. men (n = 44) × trauma type: sexual assault (n = 61) vs. other (n = 39)] and logistic regression revealed that sexual assault survivors scored higher than other trauma survivors on re-experiencing and hyperarousal PTS symptoms (DSM-5 Clusters B and E), cognitive depressive symptoms, hopelessness, cannabis use frequency, medicinal cannabis prescription, cannabis use to cope with psychological symptoms, and compulsivity craving; and lower on social and enhancement cannabis use motives. In terms of gender main effects, women scored higher than men on cannabis use to cope with negative emotions. In terms of interactions for PTS Cluster D symptoms (negative alterations in mood/cognitions), among men only, sexual assault survivors scored higher than other trauma survivors; and for cannabis enhancement motives and purposefulness cannabis craving, among sexual assault survivors only, women scored higher than men.

Discussion

Across many different trauma, women survivors' use of cannabis to cope with negative affect should be a specific therapeutic focus. Moreover, we identified specific emotional and cannabis use outcomes that should be of specific clinical concern among sexual assault survivors regardless of gender. Finally, in terms of gender differences of clinical interest among sexual assault survivors, while PTS Cluster D symptoms should be specific treatment targets in men, cannabis enhancement motives and purposefulness craving should be treatment targets in women.

Early phase psychosis and criminal conviction in United States adults

AIM

Individuals experiencing early phase psychosis (EPP) are at increased risk for legal involvement. In prior studies, between 14% and 75% of individuals with EPP reported a history of criminal offending behaviour, criminal charges, or criminal convictions. To better understand the frequency of criminal conviction in a specialty treatment clinic serving EPP clients, the research team supplemented self-reported data from the clinic intake with information from publicly available databases.

METHODS

In this sample of 309 adults, approximately one quarter of patients (n = 76) self-reported a history of arrest, incarceration, probation, or parole within 6 months of enrolment in a treatment clinic. The research team expanded upon this and collected data from a public database of court proceedings in Indiana for all clinic participants before and after enrolment.

RESULTS

Thirty-nine percent (n = 122) had three or more traffic tickets or a conviction for an ordinance violation, misdemeanour, or felony in the state of Indiana as an adult. This is over two times the national average. Drug and alcohol related convictions were the most common single conviction type, and 29% (n = 89) of subjects experienced at least one incarceration.

CONCLUSIONS

These data highlight the need for specialty clinics to partner with professionals with expertise in the prevention and management of criminal behaviour. Future studies should examine risk factors for individuals experiencing EPP and criminal conviction.

Do Anxiety Symptoms Mediate the Association Between Cannabis Use Frequency and Psychotic-Like Experiences in Emerging Adult Undergraduates?

OBJECTIVE

Cannabis is commonly used by Canadian emerging adults (ages 18-25 years), many of whom attend post-secondary institutions. Frequent cannabis use is linked with psychotic-like experiences (PLEs); however, the exact nature of this association remains unclear. Anxiety symptoms may mediate this association, as they are prevalent in emerging adults and have been independently linked with both cannabis use and PLEs. Past work found that anxiety mediated the association between cannabis use frequency and attenuated positive psychotic symptoms (further along the psychosis continuum than PLEs), however this research had yet to be validated in the Canadian population, and trait rather than state anxiety (frequency of anxiety symptoms) was studied. Thus, our primary objective was to examine if anxiety symptoms mediated the association between cannabis use frequency and PLEs in Canadian emerging adult undergraduates. Despite known sex differences in cannabis use, expression of anxiety, and PLEs, past work did not evaluate the potential impact of biological sex on the anxiety-mediated model, and thus is the secondary objective of the present study.

METHODS

1,266 first-/second-year emerging adult undergraduates from five Canadian universities provided cross-sectional, self-report survey data in fall 2021 semester. Validated measures of cannabis use frequency, anxiety, and PLEs were administered.

RESULTS

Path analyses supported mediation from cannabis use to PLEs through anxiety (b  =  0.07, P < 0.001, 95% bootstrap CI [0.03, 0.10]). No direct effect was found (P  =  0.457), suggesting that the cannabis-to-PLEs association was mediated by anxiety. Mediation did not depend on biological sex (i.e., bootstrapped 95% CIs crossed zero).

CONCLUSIONS

Anxiety symptoms mediated the association between cannabis use and PLEs in emerging adults regardless of their biological sex. Assuming replication in prospective research, results highlight anxiety as an important intervention target in frequent cannabis-using emerging adults, to potentially prevent development/worsening of PLEs, and in turn psychotic illness.

Association between cannabis use disorder and schizophrenia stronger in young males than in females

BACKGROUND

Previous research suggests an increase in schizophrenia population attributable risk fraction (PARF) for cannabis use disorder (CUD). However, sex and age variations in CUD and schizophrenia suggest the importance of examining differences in PARFs in sex and age subgroups.

METHODS

We conducted a nationwide Danish register-based cohort study including all individuals aged 16-49 at some point during 1972-2021. CUD and schizophrenia status was obtained from the registers. Hazard ratios (HR), incidence risk ratios (IRR), and PARFs were estimated. Joinpoint analyses were applied to sex-specific PARFs.

RESULTS

We examined 6 907 859 individuals with 45 327 cases of incident schizophrenia during follow-up across 129 521 260 person-years. The overall adjusted HR (aHR) for CUD on schizophrenia was slightly higher among males (aHR = 2.42, 95% CI 2.33-2.52) than females (aHR = 2.02, 95% CI 1.89-2.17); however, among 16-20-year-olds, the adjusted IRR (aIRR) for males was more than twice that for females (males: aIRR = 3.84, 95% CI 3.43-4.29; females: aIRR = 1.81, 95% CI 1.53-2.15). During 1972-2021, the annual average percentage change in PARFs for CUD in schizophrenia incidence was 4.8 among males (95% CI 4.3-5.3; p < 0.0001) and 3.2 among females (95% CI 2.5-3.8; p < 0.0001). In 2021, among males, PARF was 15%; among females, it was around 4%.

CONCLUSIONS

Young males might be particularly susceptible to the effects of cannabis on schizophrenia. At a population level, assuming causality, one-fifth of cases of schizophrenia among young males might be prevented by averting CUD. Results highlight the importance of early detection and treatment of CUD and policy decisions regarding cannabis use and access, particularly for 16-25-year-olds.

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

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

Sensory gating, neurocognition, social cognition and real-life functioning: a 2-year follow-up of early psychosis

BACKGROUND

Diminished sensory gating (SG) is a robust finding in psychotic disorders, but studies of early psychosis (EP) are rare. It is unknown whether SG deficit leads to poor neurocognitive, social, and/or real-world functioning. This study aimed to explore the longitudinal relationships between SG and these variables.

METHODS

Seventy-nine EP patients and 88 healthy controls (HCs) were recruited at baseline. Thirty-three and 20 EP patients completed 12-month and 24-month follow-up, respectively. SG was measured using the auditory dual-click (S1 & S2) paradigm and quantified as P50 ratio (S2/S1) and difference (S1-S2). Cognition, real-life functioning, and symptoms were assessed using the MATRICS Consensus Cognitive Battery, Global Functioning: Social (GFS) and Role (GFR), Multnomah Community Ability Scale (MCAS), Awareness of Social Inference Test (TASIT), and the Positive and Negative Syndrome Scale (PANSS). Analysis of variance (ANOVA), chi-square, mixed model, correlation and regression analyses were used for group comparisons and relationships among variables controlling for potential confounding variables.

RESULTS

In EP patients, P50 ratio (p < 0.05) and difference (p < 0.001) at 24-month showed significant differences compared with that at baseline. At baseline, P50 indices (ratio, S1-S2 difference, S1) were independently associated with GFR in HCs (all p < 0.05); in EP patients, S2 amplitude was independently associated with GFS (p = 0.037). At 12-month and 24-month, P50 indices (ratio, S1, S2) was independently associated with MCAS (all p < 0.05). S1-S2 difference was a trending predictor of future function (GFS or MCAS).

CONCLUSIONS

SG showed progressive reduction in EP patients. P50 indices were related to real-life functioning.

Substance use Specificities in Women with Psychosis: A Critical Review

BACKGROUND

Women with schizophrenia or other psychotic disorders differ from male patients in many respects, including psychopathology, prognosis, disease course, and substance use comorbidities. Most studies performed to date to investigate the association between drug use and psychosis have not evaluated gender differences, although this has started to change in recent years.

METHODS

We briefly summarize the available evidence on gender differences in drug use and substance use disorders (SUD) in psychotic patients during the early phases of the psychotic illness and during the course of schizophrenia.

RESULTS

Substance use and SUD are both less prevalent in women, both in the general population and at all phases of the psychotic spectrum. Some studies suggest that SUD may be under diagnosed in female patients, in part due to their more vulnerable profile. Substance use, especially cannabis, may more negatively impact females, especially on the disease course and prognosis. The available data suggest that it may be more difficult to treat SUD in female patients with schizophrenia, which could negatively impact prognosis.

CONCLUSION

Women with concomitant psychotic illness and SUD comprise a highly vulnerable subgroup. This should be considered when selecting the treatment approach, especially in the early phases of the illness, to ensure better outcomes.

Reducing Cannabis Use in Young Adults With Psychosis Using iCanChange, a Mobile Health App: Protocol for a Pilot Randomized Controlled Trial (ReCAP-iCC)

BACKGROUND

Cannabis use is the most prevalent among adolescents and young adults; frequent consumption is associated with cannabis use disorder (CUD) and psychosis, with a high prevalence (up to 50%) of CUD in individuals with first-episode psychosis (FEP). Early Intervention Services (EIS) for psychosis include face-to-face psychosocial interventions for CUD, because reducing or discontinuing cannabis use improves clinical and health care service use outcomes. However, multiple barriers (eg, staff availability and limited access to treatment) can hinder the implementation of these interventions. Mobile health (mHealth) interventions may help circumvent some of these barriers; however, to date, no study has evaluated the effects of mHealth psychological interventions for CUD in individuals with FEP.

OBJECTIVE

This study describes the protocol for a pilot randomized controlled trial using a novel mHealth psychological intervention (iCanChange [iCC]) to address CUD in young adults with FEP. iCC was developed based on clinical evidence showing that in individuals without psychosis, integrating the principles of cognitive behavioral therapy, motivational interviewing, and behavioral self-management approaches are effective in improving cannabis use-related outcomes.

METHODS

Consenting individuals (n=100) meeting the inclusion criteria (eg, aged 18-35 years with FEP and CUD) will be randomly allocated in a 1:1 ratio to the intervention (iCC+modified EIS) or control (EIS) group. The iCC is fully automatized and contains 21 modules that are completed over a 12-week period and 3 booster modules available during the 3-month follow-up period. Validated self-report measures will be taken via in-person assessments at baseline and at 6, 12 (end point), and 24 weeks (end of trial); iCC use data will be collected directly from the mobile app. Primary outcomes are intervention completion and trial retention rates, and secondary outcomes are cannabis use quantity, participant satisfaction, app use, and trial recruiting parameters. Exploratory outcomes include severity of psychotic symptoms and CUD severity. For primary outcomes, we will use the chi-square test using data collected at week 12. We will consider participation in iCC acceptable if ≥50% of the participants complete at least 11 out of 21 intervention modules and the trial feasible if attrition does not reach 50%. We will use analysis of covariance and mixed-effects models for secondary outcomes and generalized estimating equation multivariable analyses for exploratory outcomes.

RESULTS

Recruitment began in July 2022, and data collection is anticipated to be completed in July 2024. The main results are expected to be submitted for publication in 2024. We will engage patient partners and other stakeholders in creating a multifaceted knowledge translation plan to reach a diverse audience.

CONCLUSIONS

If feasible, this study will provide essential data for a larger-scale efficacy trial of iCC on cannabis use outcomes in individuals with FEP and CUD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05310981; https://www.clinicaltrials.gov/ct2/show/NCT05310981.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/40817.

Gender Differences in Dual Diagnoses Associated with Cannabis Use: A Review

Gender differences in psychiatric disorders and drug use are well known. Cannabis is the most widely used illegal drug among young people. In recent years, its use has been related to the development of psychiatric pathologies; however, few studies have incorporated the gender perspective as of yet. The present work analyses the literature to determine the existence of gender differences in the development of psychotic, depressive and anxious symptoms associated with cannabis use. First, we describe cannabis misuse and its consequences, paying special attention to adolescent subjects. Second, the main gender differences in psychiatric disorders, such as psychosis, depression, anxiety and cannabis use disorders, are enumerated. Subsequently, we discuss the studies that have evaluated gender differences in the association between cannabis use and the appearance of psychotic, depressive and anxious symptoms; moreover, we consider the possible explanations for the identified gender differences. In conclusion, the studies referred to in this review reveal the existence of gender differences in psychiatric symptoms associated with cannabis use, although the direction of such differences is not always clear. Future research is necessary to discern the causal relationship between cannabis use and the development of psychiatric symptoms, as well as the gender differences found.

Treatment-resistant schizophrenia: Addressing white matter integrity, intracortical glutamate levels, clinical and cognitive profiles between early- and adult-onset patients

BACKGROUND

Treatment-resistance in schizophrenia is 30-40%. Its neurobiology remains unclear; to explore it, we conducted a combined spectrometry/tractography/cognitive battery and psychopathological rating study on patients with treatment-resistant schizophrenia (TRS), dividing the sample into early-onset (N = 21) and adult-onset TRS (N = 20). Previous studies did not differentiate between early- (onset 13-18 years) and adult-onset (>18 years at formal diagnosis of schizophrenia) TRS.

METHODS

We evaluated cross-sectionally 41 TRS patients (26 male and 15 female) and 20 matched healthy controls (HCs) with psychopathological and cognitive testing prior to participating in brain imaging scanning using magnetic resonance spectroscopy and diffusion tensor imaging to determine the relationship between their symptoms and their glutamate levels and white matter integrity.

RESULTS

TRS patients scored lower than HCs on all cognitive domains; early-onset patients performed better than adult-onset patients only on the Symbol Coding domain. TRS correlated with symptom severity, especially negative symptoms. Glutamate levels and glutamate/creatine were increased in anterior cingulate cortex. Diffusion tensor imaging showed low fractional anisotropy in TRS patients in specific white matter tracts compared to HCs (bilateral anterior thalamic radiation, cortico-spinal tract, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and right uncinate fasciculus).

CONCLUSIONS

We identified specific magnetic resonance spectroscopy and diffusion tensor imaging alterations in TRS patients. Adult-onset TRS differed little from early-onset TRS on most measures; this points to alterations being present since the outset of schizophrenia and may constitute a biological signature of treatment-resistance.

US trends in the association of suicide ideation/behaviors with marijuana use among adolescents ages 12-17 and differences by gender and race/ethnicity

BACKGROUND

In the US over the past decade, there has been a steady increase in marijuana use rates among adolescents, in part due to marijuana legalization laws. It is unknown whether these greater marijuana use rates are associated with rising rates of adolescent suicide ideation and behaviors (plan and attempt) or whether these associations differ by gender or race/ethnicity.

OBJECTIVE

To determine whether marijuana use is associated with suicide ideation/behaviors among adolescents and if differences exist by gender and race/ethnicity.

MATERIALS AND METHODS

Using the 2015-2019 National Surveys on Drug Use and Health, we assessed the relationship between marijuana use frequency and suicide ideation/behaviors among adolescents (12-17, n = 73,986). We also examined the association with marijuana use disorder (MUD) and assessed differences by gender and race/ethnicity. Marijuana use frequency in the past year was categorized as no use, non-weekly use, and weekly-plus use. We estimated multivariable logistic regression models, adjusting for sociodemographics, health status, common co-occurring behavioral health disorders, and criminal history. For interpretability, regression coefficients were converted into predicted probabilities using predictive margin methods.

RESULTS

In primary analyses, adolescents with non-weekly use and weekly-plus use had higher rates of any suicide ideation, 61.5% (+ 10.4 percentage-points; 95% CI: 7.0-13.8%) and 64.5% (+ 13.4 percentage-points; 95% CI: 9.1-17.7%), relative to no use (51.1%). Non-weekly and weekly-plus use was associated with higher rates of any suicide plan 58.2% (+ 11.8 percentage-points; 95% CI: 7.8-16.0%) and 59.0% (+ 12.6 percentage-points; 95% CI: 6.4-18.9%), and any suicide attempt, 42.0% (+ 11.6 percentage-points; 95% CI: 7.0-16.2%) and 47.3% (+ 16.9 percentage-points; 95% CI: 10.9-22.9%) compared to no use (46.4 and 30.4%, respectively). Similar results were found among adolescents with a MUD (all p < 0.05). Positive associations between marijuana use and suicide ideation/behaviors persisted among males and females as well as White, Black, and Latinx adolescents (all p < 0.05).

CONCLUSION

Between 2015 and 2019, suicide ideation/behaviors increased for adolescents that used marijuana. As marijuana is legalized in more states, public health efforts are needed to curb increases in marijuana use among adolescents and to better understand the causal linkages between marijuana use and suicide ideation/behaviors.

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.

The Link Between Cannabis Use and Violent Behavior in the Early Phase of Psychosis: The Potential Role of Impulsivity

INTRODUCTION

Recently, the literature has shown that Cannabis Use (CU) was a risk factor for Violent Behavior (VB) in patients with psychosis, and those in the early phase of psychosis (EPP). These findings are relevant because of the high prevalence of CU in this EPP, and the potential for prevention during this phase of illness. However, there is still a lack of clear explanations, supported by empirical evidence, about what underlies the link between CU and VB against other.

METHOD

This viewpoint reviews the scientific literature on the link between CU and VB, and the involvement of impulsivity in this relationship. This last point will be addressed at clinical and neurobiological levels.

RESULTS

Recent studies confirmed that CU is particularly high in the EPP, and is a risk factor for VB in the EPP and schizophrenia. Studies have also shown that impulsivity is a risk factor for VB in psychosis, is associated with CU, and may mediate the link between CU and VB. Research suggests a neurobiological mechanism, as CU affects the structures and function of frontal areas, known to play a role in impulsive behavior.

CONCLUSION

Scientific evidence support the hypothesis of an involvement of impulsivity as a variable that could mediate the link between CU and aggression, particularly, when CU has an early onset. However, this hypothesis should be confirmed with longitudinal studies and by taking into account confounding factors. The studies highlight the relevance of early prevention in the EPP, in addition to interventions focusing on psychotic disorders.

Acute effects of cannabis on speech illusions and psychotic-like symptoms: two studies testing the moderating effects of cannabidiol and adolescence

BACKGROUND

Acute cannabis administration can produce transient psychotic-like effects in healthy individuals. However, the mechanisms through which this occurs and which factors predict vulnerability remain unclear. We investigate whether cannabis inhalation leads to psychotic-like symptoms and speech illusion; and whether cannabidiol (CBD) blunts such effects (study 1) and adolescence heightens such effects (study 2).

METHODS

Two double-blind placebo-controlled studies, assessing speech illusion in a white noise task, and psychotic-like symptoms on the Psychotomimetic States Inventory (PSI). Study 1 compared effects of Cann-CBD (cannabis containing Δ-9-tetrahydrocannabinol (THC) and negligible levels of CBD) with Cann+CBD (cannabis containing THC and CBD) in 17 adults. Study 2 compared effects of Cann-CBD in 20 adolescents and 20 adults. All participants were healthy individuals who currently used cannabis.

RESULTS

In study 1, relative to placebo, both Cann-CBD and Cann+CBD increased PSI scores but not speech illusion. No differences between Cann-CBD and Cann+CBD emerged. In study 2, relative to placebo, Cann-CBD increased PSI scores and incidence of speech illusion, with the odds of experiencing speech illusion 3.1 (95% CIs 1.3-7.2) times higher after Cann-CBD. No age group differences were found for speech illusion, but adults showed heightened effects on the PSI.

CONCLUSIONS

Inhalation of cannabis reliably increases psychotic-like symptoms in healthy cannabis users and may increase the incidence of speech illusion. CBD did not influence psychotic-like effects of cannabis. Adolescents may be less vulnerable to acute psychotic-like effects of cannabis than adults.

Cannabis use and hippocampal subfield volumes in males with a first episode of a schizophrenia spectrum disorder and healthy controls

BACKGROUND

Both schizophrenia and cannabis use are associated with structural brain changes. The hippocampus is a region of particular interest due to its role in memory and select cognitive functions, impairment of which is a core feature of schizophrenia and has also been observed in substance abuse. This study aimed to explore the effects of recent/current cannabis use on hippocampal subfield volumes in male patients with first-episode schizophrenia spectrum disorders and matched controls.

METHODS

This cross-sectional, case-control study included 63 patients and 58 controls scanned on 3T MRI scanners, with hippocampal segmentation performed using recently validated Freesurfer v6.0 software. Cannabis use status was determined by self and carer report together with urine toxicology screening, and patients were categorised as recent/current users or non-users. We used multivariate analysis of covariance (MANCOVA) with age, scan sequence, scan quality, and total intracranial volume as covariates, with subsequent analysis of variance (ANOVA) to test the effects of diagnosis and cannabis use status on individual hippocampal subfields.

RESULTS

We found a group (patient/control) by cannabis use interaction effect in the subiculum, with decreased volumes observed in the cannabis non-using patients compared to the cannabis using patients, and decreased volumes in the cannabis using controls compared to the cannabis non-using controls.

CONCLUSION

The increased subiculum volume in cannabis using patients compared to cannabis non-using patients raises important questions regarding the pathophysiology of schizophrenia and the role of cannabis use therein.

Psychosocial and pharmacological treatments for cannabis use disorder and mental health comorbidities: a narrative review

Cannabis is the most widely used illicit drug worldwide, and it is estimated that up to 30% of people who use cannabis will develop a cannabis use disorder (CUD). Demand for treatment of CUD is increasing in almost every region of the world and cannabis use is highly comorbid with mental disorders, where sustained use can reduce treatment compliance and increase risk of relapse. In this narrative review, we outline evidence for psychosocial and pharmacological treatment strategies for CUD, both alone and when comorbid with psychosis, anxiety or depression. Psychosocial treatments such as cognitive behavioural therapy, motivational enhancement therapy and contingency management are currently the most effective strategy for treating CUD but are of limited benefit when comorbid with psychosis. Pharmacological treatments targeting the endocannabinoid system have the potential to reduce cannabis withdrawal and cannabis use in CUD. Mental health comorbidities including anxiety, depression and psychosis hinder effective treatment and should be addressed in treatment provision and clinical decision making to reduce the global burden of CUDs. Antipsychotic medication may decrease cannabis use and cannabis craving as well as psychotic symptoms in patients with CUD and psychosis. Targeted treatments for anxiety and depression when comorbid with CUD are feasible.

When Cannabis Use Goes Wrong: Mental Health Side Effects of Cannabis Use That Present to Emergency Services

Cannabis use is a modifiable risk factor for the development and exacerbation of mental illness. The strongest evidence of risk is for the development of a psychotic disorder, associated with early and consistent use in youth and young adults. Cannabis-related mental health adverse events precipitating Emergency Department (ED) or Emergency Medical Services presentations can include anxiety, suicidal thoughts, psychotic or attenuated psychotic symptoms, and can account for 25-30% of cannabis-related ED visits. Up to 50% of patients with cannabis-related psychotic symptoms presenting to the ED requiring hospitalization will go on to develop schizophrenia. With the legalization of cannabis in various jurisdiction and the subsequent emerging focus of research in this area, our understanding of who (e.g., age groups and risk factors) are presenting with cannabis-related adverse mental health events in an emergency situation is starting to become clearer. However, for years we have heard in popular culture that cannabis use is less harmful or no more harmful than alcohol use; however, this does not appear to be the case for everyone. It is evident that these ED presentations should be considered another aspect of potentially harmful outcomes that need to be included in knowledge mobilization. In the absence of a clear understanding of the risk factors for mental health adverse events with cannabis use it can be instructive to examine what characteristics are seen with new presentations of mental illness both in emergency departments (ED) and early intervention services for mental illness. In this narrative review, we will discuss what is currently known about cannabis-related mental illness presentations to the ED, discussing risk variables and outcomes both prior to and after legalization, including our experiences following cannabis legalization in Canada. We will also discuss what is known about cannabis-related ED adverse events based on gender or biological sex. We also touch on the differences in magnitude between the impact of alcohol and cannabis on emergency mental health services to fairly present the differences in service demand with the understanding that these two recreational substances may impact different populations of individuals at risk for adverse events.

The impact of sex and cannabis on clinical features in first-admitted patients with psychosis

There is a scarcity of studies investigating the effect of sex on the clinical and treatment characteristics of first-admitted patients with first-episode psychosis (FEP). The reasons for using cannabis and the effect of cannabis on clinical features have not received enough attention either. We aim therefore, to investigate sex differences in the reasons for cannabis use and to determine the effects of sex, cannabis use and their interaction on clinical variables at admission and at discharge from the inpatient unit. 204 first-admitted FEPs in two inpatient units in Spain were included. The reasons for using cannabis were determined using the Dixon questionnaire. Clinical variables were compared between sexes and between cannabis users and non-users. Cannabis use was more frequent in males, but females were more likely to smoke cannabis to "feel relaxed". There was a main effect of sex on positive psychotic symptoms and antipsychotics dose and an interaction effect of cannabis and sex on global functioning at discharge .Our findings show sex differences in the reasons for cannabis use and in some clinical and treatment characteristics among FEP patients. More studies focusing on gender perspectives are needed to develop more individualized treatments.

Do we need sex-oriented clinical practice guidelines for the treatment of schizophrenia?

PURPOSE OF REVIEW

Clinical practice guidelines (CPGs) do not usually offer a sex-specific approach for the management of schizophrenia. With this narrative review, we aim to give an integrated and synthesized overview of the current state of knowledge regarding sex-specific aspects in schizophrenia and how this topic may be adapted in the development of CPGs.

RECENT FINDINGS

Recent studies further suggest sex-specific differences in epidemiologic features, the course of illness, underlying pathomechanisms, response likelihood to antipsychotic medication and differences in tolerability. Beyond this, selective estrogen receptor modulators like raloxifene have shown beneficial effects on symptom severity and cognition in women with schizophrenia.

SUMMARY

Sex-specific aspects can already be integrated in clinical guideline recommendations, especially with regard to efficacy and tolerability of antipsychotic treatment. Moreover, these aspects may be used for an individual risk-stratification. Recent studies provide evidence supporting the hypothesis of sex-specific modulation in schizophrenia and build the groundwork for sex-specific novel treatment options. However, there remains a clear need for additional studies focusing on women with schizophrenia to substantiate current findings.

Substance use disorders before, at and after first episode psychosis hospitalizations in a young national Swedish cohort

BACKGROUND

Comorbidity between Substance use disorders (SUD) and psychotic disorders is common but the temporal relation of the first episodes of SUD and psychosis and how it affects the disorders has not been extensively investigated.

METHODS

A nation-wide cohort (n = 2494) with a first hospitalization for psychosis at ages between 16 and 25 was identified. Psychiatric hospitalizations were followed from birth until up to 5 years after the first psychosis hospitalization. Risk factors for new SUD or psychosis hospitalization after the index hospitalization were analyzed by Cox regression.

RESULTS

30 % of the cases had SUD hospitalizations in the 5 years before or as a comorbid diagnosis at the first psychosis hospitalization. An additional 9% had a first SUD hospitalization in the five years after. The incidence of SUD hospitalizations increased year by year before and decrease year by year after the index hospitalization. The hazard ratio for a new SUD hospitalizations after the index hospitalization was significantly higher (hazard ratio 6.7, p-value<0.001) in cases with SUD before or at the index hospitalization compared to in cases without previous SUD. In cases with previous SUD, there was a strong association (p < 0.001) between a new psychosis hospitalization and a new SUD hospitalization the year after the index hospitalization, indicating that SUD may continue to aggravate the psychotic disorder in this group.

CONCLUSIONS

SUD is very common before a first hospital treated psychosis. The SUD likely aggravates early psychotic disorders in many cases.

Effects of cannabis exposure in the prenatal and adolescent periods: Preclinical and clinical studies in both sexes

Cannabis is the most commonly used illicit drug among adolescents and young adults, including pregnant women. There is substantial evidence for a significant association between prenatal cannabis exposure and lower birth weight in offspring, and mixed results regarding later behavioural outcomes in the offspring. Adolescent cannabis use, especially heavy use, has been associated with altered executive function, depression, psychosis and use of other drugs later in life. Human studies have limitations due to several confounding factors and have provided scarce information about sex differences. In general, animal studies support behavioural alterations reported in humans and have revealed diverse sex differences and potential underlying mechanisms (altered mesolimbic dopaminergic and hippocampal glutamatergic systems and interference with prefrontal cortex maturation). More studies are needed that analyse sex and gender influences on cannabis-induced effects with great clinical relevance such as psychosis, cannabis use disorder and associated comorbidities, to achieve more personalized and accurate treatments.

The impact of gender and childhood abuse on age of psychosis onset, psychopathology and needs for care in psychosis patients

Gender is associated with several features of psychotic disorders, including age of illness onset, symptomatology, a higher prevalence of history of childhood sexual abuse (CSA) and needs for care. Childhood sexual abuse is associated with adverse mental health consequences but as there is a gender difference in stress reactivity, there may be a differential impact of CSA on psychopathology, age of psychosis onset and needs for care in First Episode Psychosis (FEP) patients. We hypothesized that a history of abuse would be associated with lowering of age of onset, increased symptomatology and more unmet needs in women but not men. A total of 444 FEP patients have been recruited within the context of the GET UP trial. Symptomatology has been assessed using the PANSS scale, needs for care with the CAN scale and childhood abuse with the CECA-Q scale. Childhood sexual abuse was more frequent among female patients [22.6% in women vs 11.6% in men (OR = 0.45, p < 0.01)], whereas there was no gender difference in the prevalence of childhood physical abuse (29.0% in women vs 31.7% in men). Childhood abuse was associated with higher levels of negative symptoms in both men and women, with a reduced age of onset in women only and little increase in needs for care in both men and women. Our results seem to suggest that childhood sexual abuse in female FEP patients may be linked to a more severe form of psychosis whose presentation is characterized by earlier age of onset and higher levels of negative symptoms and we can also speculate that gender-specific protective factors in women, but not in men, may be outweighed by the consequences of childhood abuse.

Cannabis and Psychosis: Are We any Closer to Understanding the Relationship?

PURPOSE OF REVIEW

This paper provides an update from the literature on understanding of the relationship between cannabis and schizophrenia. In particular, the paper focuses on the latest findings and remaining areas that require investigation.

RECENT FINDINGS

Three hypotheses have emerged as potential explanations for the association between cannabis and schizophrenia, namely cannabis can trigger schizophrenia, cannabis is used to mitigate symptoms of schizophrenia, and there are common factors which might account for the association. Biological and genetic factors dominate this field of research; this has been at the expense of exploring social and cultural contributory factors which influence cannabis and schizophrenia. The evidence for cannabis acting as a causal factor for schizophrenia has so far not been established. Research needs to extend beyond males drawn from western countries if we are to advance knowledge and understanding of the link between cannabis use and schizophrenia.

Sex and gender differences in schizophrenic psychoses-a critical review

Many sex and gender differences in schizophrenic psychoses have been reported, but few have been soundly replicated. A stable finding is the later age of onset in women compared to men. Gender differences in symptomatology, comorbidity, and neurocognition seem to reflect findings in the general population. There is increasing evidence for estrogens being psychoprotective in women and for hypothalamic-pituitary-gonadal dysfunction in both sexes.More methodologically sound, longitudinal, multi-domain, interdisciplinary research investigating both sex (biological) and gender (psychosocial) factors is required to better understand the different pathogenesis and etiologies of schizophrenic psychoses in women and men, thereby leading to better tailored treatments and improved outcomes.

Prevalence of comorbid substance use in schizophrenia spectrum disorders in community and clinical settings, 1990-2017: Systematic review and meta-analysis

BACKGROUND

Comorbidity is highly prevalent between substance use disorders (SUDs) and schizophrenia. This systematic review and meta-analysis estimated prevalence rates of SUDs in epidemiological and treatment-seeking patients diagnosed with schizophrenia or first episode psychosis.

METHODS

A literature search of Medline, EMBASE, PsycINFO and CINAHL databases was conducted from 1990 to 2017 inclusive. Prevalence of co-morbid SUDs and schizophrenia were extracted and odds ratios (ORs) were calculated using random effects meta-analysis. Combining like studies was dictated how authors reported substance use.

RESULTS

There were 123 included articles with a total sample size of 165,811 subjects that yielded six epidemiological studies, 11 national or state case-registry studies, 20 large cohort studies and 86 clinical studies using in- or out-patient samples. The prevalence of any SUD was 41.7%, followed by illicit drugs (27.5%), cannabis (26.2%), alcohol (24.3%) and stimulant use (7.3%). Meta-analysis showed the pooled variance of any SUD in males was 48% which was significantly higher than that for females with schizophrenia (22.1%, OR 3.43, 95% CI 3.01, 3.92). Patients with SUD had an earlier age of onset of schizophrenia. Meta-regression showed prevalence increased over time for illicit drugs but not for other substances, including alcohol.

CONCLUSIONS

The meta-analysis revealed that SUDs in schizophrenia is highly prevalent and rates have not changed over time. This indicates SUD are difficult to treat in this patient population and there is an urgent need for more informative studies to help develop better prevention, detection and treatment of SUDs in persons with schizophrenia and co-morbid disorders.