Epidemiologic research suggests that youth cannabis use is associated with psychotic disorders. However, current evidence is based heavily on 20th-century data when cannabis was substantially less potent than today.

We linked population-based survey data from 2009 to 2012 with records of health services covered under universal healthcare in Ontario, Canada, up to 2018. The cohort included respondents aged 12–24 years at baseline with no prior psychotic disorder (N = 11 363). The primary outcome was days to first hospitalization, ED visit, or outpatient visit related to a psychotic disorder according to validated diagnostic codes. Due to non-proportional hazards, we estimated age-specific hazard ratios during adolescence (12–19 years) and young adulthood (20–33 years). Sensitivity analyses explored alternative model conditions including restricting the outcome to hospitalizations and ED visits to increase specificity.

Compared to no cannabis use, cannabis use was significantly associated with psychotic disorders during adolescence (aHR = 11.2; 95% CI 4.6–27.3), but not during young adulthood (aHR = 1.3; 95% CI 0.6–2.6). When we restricted the outcome to hospitalizations and ED visits only, the strength of association increased markedly during adolescence (aHR = 26.7; 95% CI 7.7–92.8) but did not change meaningfully during young adulthood (aHR = 1.8; 95% CI 0.6–5.4).

This study provides new evidence of a strong but age-dependent association between cannabis use and risk of psychotic disorder, consistent with the neurodevelopmental theory that adolescence is a vulnerable time to use cannabis. The strength of association during adolescence was notably greater than in previous studies, possibly reflecting the recent rise in cannabis potency.

Measurement-based care (MBC) in mental health improves patient outcomes and is a component of many national guidelines for mental healthcare delivery. Nevertheless, MBC is not routinely integrated into clinical practice. Several known reasons for the lack of integration exist but one lesser explored variable is the subjective perspectives of providers and patients about MBC. Such perspectives are critical to understand facilitators and barriers to improve the integration of MBC into routine clinical practice.

This study aimed to uncover the perspectives of various stakeholders towards MBC within a single treatment centre.

Researchers conducted qualitative semi-structured interviews with patients (n = 15), family members (n = 7), case managers (n = 8) and psychiatrists (n = 6) engaged in an early-psychosis intervention programme. Data were analysed using thematic analysis, informed by critical realist theory.

Analysis converged on several themes. These include (a) implicit negative assumptions; (b) relevance and utility to practice; (c) equity versus flexibility; and (d) shared decision-making. Providers assumed patients’ perspectives of MBC were negative. Patients’ perspectives of MBC were actually favourable, particularly if MBC was used as an instrument to engage patients in shared decision-making and communication rather than as a dogmatic and rigid clinical decision tool.

This qualitative study presents the views of various stakeholders towards MBC, providing an in-depth examination of the barriers and facilitators to MBC through qualitative investigation. The findings from this study should be used to address the challenges organisations have experienced in implementing MBC.

Social determinants of health have the potential to influence mental health and addictions-related emergency department (ED) visits and the likelihood of admission to hospital. We aimed to determine how social determinants of health, individually and in combination, relate to the likelihood of hospital admission at the time of postpartum psychiatric ED visits.

Among 10 702 postpartum individuals (female based on health card) presenting to the ED for a psychiatric reason in Ontario, Canada (2008–2017), we evaluated the relation between six social determinants of health (age, neighbourhood quintile [Q, Q1 = lowest, Q5 = highest], rurality, immigrant category, Chinese or South Asian ethnicity and neighbourhood ethnic diversity) and the likelihood of hospital admission from the ED. Poisson regression models generated relative risks (RR, 95% CI) of admission for each social determinant, crude and adjusted for clinical severity (diagnosis and acuity) and other potential confounders. Generalised estimating equations were used to explore additive interaction to understand whether the likelihood of admission depended on intersections of social determinants of health.

In total, 16.0% (n = 1715) were admitted to hospital from the ED. Being young (age 19 or less v. 40 or more: RR 0.60, 95% CI 0.45–0.82), rural-dwelling (v. urban-dwelling: RR 0.75, 95% CI 0.62–0.91) and low-income (Q1 v. Q5: RR 0.81, 95% CI 0.66–0.98) were each associated with a lower likelihood of admission. Being an immigrant (non-refugee immigrant v. Canadian-born/long-term resident: RR 1.29, 95% CI 1.06–1.56), of Chinese ethnicity (v. non-Chinese/South Asian ethnicity: RR 1.88, 95% CI 1.42–2.49); and living in the most v. least ethnically diverse neighbourhoods (RR 1.24, 95% CI 1.01–1.53) were associated with a higher likelihood of admission. Only Chinese ethnicity remained significant in the fully-adjusted model (aRR 1.49, 95% CI 1.24–1.80). Additive interactions were non-significant.

For the most part, whether a postpartum ED visit resulted in admission from the ED depended primarily on the clinical severity of presentation, not on individual or intersecting social determinants of health. Being of Chinese ethnicity did increase the likelihood of admission independent of clinical severity and other measured factors; the reasons for this warrant further exploration.

Individuals with eating disorders have a high mortality risk. Few population-based studies have estimated this risk in eating disorders other than anorexia nervosa.

To investigate all-cause mortality in a population-based cohort of individuals who received hospital-based care for an eating disorder (anorexia nervosa, bulimia nervosa or eating disorder not otherwise specified) in Ontario, Canada.

We conducted a retrospective cohort study of 19 041 individuals with an eating disorder from 1 January 1990 to 31 December 2013 using administrative healthcare data. The outcome of interest was death. Excess mortality was assessed using standardised mortality ratios (SMRs) and potential years of life lost (PYLL). Cox proportional hazards regression models were used to examine sociodemographic and medical comorbidities associated with greater mortality risk.

The cohort had 17 108 females (89.9%) and 1933 males (10.1%). The all-cause mortality for the entire cohort was five times higher than expected compared with the Ontario population (SMR = 5.06; 95% CI 4.82–5.30). SMRs were higher for males (SMR = 7.24; 95% CI 6.58–7.96) relative to females (SMR = 4.59; 95% CI 4.34–4.85) overall, and in all age groups in the cohort. For both genders, the cohort PYLL was more than six times higher than the expected PYLL in the Ontario population.

Patients with eating disorders diagnosed in hospital settings experience five to seven times higher mortality rates compared with the overall population. There is an urgent need to understand the mortality risk factors to improve health outcomes among individuals with eating disorders.

Relatively few studies have assessed the prevalence, correlates, and independent impact on quality of life (QoL) of trichotillomania (TTM) in large samples.

Consecutive participants (N = 7639) were recruited from a cross-sectional web-based study. Sociodemographic data were collected and several validated self-reported mental health measures were completed (Minnesota Impulsive Disorders Interview, Hypomania checklist, Fagerström Test for Nicotine Dependence, Alcohol Use Disorders Identification Test, Early Trauma Inventory Self Report–Short Form, and the Symptom Checklist-90–Revised Inventory). Health-related QoL was assessed with the World Health Organization QoL abbreviated scale (WHOQOL-Bref). Multivariable models adjusted associations to potential confounders.

The sample was predominantly composed of young females (71.3%; mean age: 27.2 ± 7.9 years). The prevalence of probable TTM was 1.4% (95% confidence intervals [CI]: 1.2-1.7), and was more common among females. Participants with probable TTM had a greater likelihood of having co-occurring probable depression (adjusted odds ratio [ORadj] = 1.744; 95% CI: 1.187-2.560), tobacco (ORadj = 2.250; 95% CI: 1.191-4.250), and alcohol (ORadj = 1.751; 95% CI: 1.169-2.621) use disorders. Probable TTM was also independently associated with suicidal ideation (ORadj = 1.917; 95% CI: 1.224-3.003) and exposure to childhood sexual abuse (ORadj = 1.221; 95% CI: 1.098-1.358). In addition, a positive screen for TTM had more impaired physical and mental QoL.

TTM was associated with a positive screen for several psychiatric comorbidities as well as impaired physical and psychological QoL. Efforts towards the recognition and treatment of TTM across psycho-dermatology services are warranted.

There is substantial variability in involuntary psychiatric admission rates across countries and sub-regions within countries that are not fully explained by patient-level factors. We sought to examine whether in a government-funded health care system, physician payments for filling forms related to an involuntary psychiatric hospitalization were associated with the likelihood of an involuntary admission.

This is a population-based, cross-sectional study in Ontario, Canada of all adult psychiatric inpatients in Ontario (2009–2015, n = 122 851). We examined the association between the proportion of standardized forms for involuntary admissions that were financially compensated and the odds of a patient being involuntarily admitted. We controlled for socio-demographic characteristics, clinical severity, past-health care system utilization and system resource factors.

Involuntary admission rates increased from the lowest (Q1, 70.8%) to the highest (Q5, 81.4%) emergency department (ED) quintiles of payment, with the odds of involuntary admission in Q5 being nearly significantly higher than the odds of involuntary admission in Q1 after adjustment (aOR 1.73, 95% CI 0.99–3.01). With payment proportion measured as a continuous variable, the odds of involuntary admission increased by 1.14 (95% CI 1.03–1.27) for each 10% absolute increase in the proportion of financially compensated forms at that ED.

We found that involuntary admission was more likely to occur at EDs with increasing likelihood of financial compensation for invoking involuntary status. This highlights the need to better understand how physician compensation relates to the ethical balance between the right to safety and autonomy for some of the world's most vulnerable patients.

As life expectancy increases, more people have chronic psychiatric and medical health disorders. Comorbidity may increase the risk of premature mortality, an important challenge for health service delivery.

Population-based cohort study in Ontario, Canada of all 11 246 910 residents aged ⩾16 and <105 on 1 April 2012 and alive on 31 March 2014. Secondary analyses included subjects having common medical disorders in 10 separate cohorts. Exposures were psychiatric morbidity categories identified using aggregated diagnosis groups (ADGs) from Johns Hopkins Adjusted Clinical Groups software® (v10.0); ADG 25: Persistent/Recurrent unstable conditions; e.g. acute schizophrenic episode, major depressive disorder (recurrent episode), ADG 24: Persistent/Recurrent stable conditions; e.g. depressive disorder, paranoid personality disorder, ADG 23: Time-limited/minor conditions; e.g. adjustment reaction with brief depressive reaction. The outcome was all-cause mortality (April 2014–March 2016).

Over 2 years' follow-up, there were 188 014 deaths (1.7%). ADG 25 conferred an almost threefold excess mortality after adjustment compared to having no psychiatric morbidity [adjusted hazard ratio 2.94 (95% CI 2.91–2.98, p < 0.0001)]. Adjusted hazard ratios for ADG 24 and ADG 23 were 1.12 (95% CI 1.11–1.14, p < 0.0001) and 1.31 (95% CI 1.26–1.36, p < 0.0001). In all 10 medical disorder cohorts, ADG 25 carried significantly greater mortality risk compared to no psychiatric comorbidity.

Psychiatric disorders, particularly those graded persistent/recurrent and unstable, were associated with excess mortality in the whole population, and in the medical disorder cohorts examined. Future research should examine whether service design accounting for psychiatric disorder comorbidity improves outcomes across the spectrum of medical disorders.

Ethnic minority groups often have more complex and aversive pathways to mental health care. However, large population-based studies are lacking, particularly regarding involuntary hospitalisation. We sought to examine the risk of involuntary admission among first-generation ethnic minority groups with early psychosis in Ontario, Canada.

Using health administrative data, we constructed a retrospective cohort (2009–2013) of people with first-onset non-affective psychotic disorder aged 16–35 years. This cohort was linked to immigration data to ascertain migrant status and country of birth. We identified the first involuntary admission within 2 years and compared the risk of involuntary admission for first-generation migrant groups to the general population. To control for the role of migrant status, we restricted the sample to first-generation migrants and examined differences by country of birth, comparing risk of involuntary admission among ethnic minority groups to a European reference. We further explored the role of migrant class by adjusting for immigrant vs refugee status within the migrant cohort. We also explored effect modification of migrant class by ethnic minority group.

We identified 15 844 incident cases of psychotic disorder, of whom 19% (n = 3049) were first-generation migrants. Risk of involuntary admission was higher than the general population in five of seven ethnic minority groups. African and Caribbean migrants had the highest risk of involuntary admission (African: risk ratio (RR) = 1.52, 95% CI = 1.34–1.73; Caribbean: RR = 1.58, 95% CI = 1.37–1.82), and were the only groups where the elevated risk persisted when compared to the European reference group within the migrant cohort (African: RR = 1.24, 95% CI = 1.04–1.48; Caribbean: RR = 1.29, 95% CI = 1.07–1.56). Refugee status was independently associated with involuntary admission (RR = 1.16, 95% CI = 1.02–1.32); however, this risk varied by ethnic minority group, with Caribbean refugees having an elevated risk of involuntary admission compared with Caribbean immigrants (RR = 1.72, 95% CI = 1.15–2.58).

Our findings are consistent with the international literature showing increased rates of involuntary admission among some ethnic minority groups with early psychosis. Interventions aimed at improving pathways to care could be targeted at these groups to reduce disparities.

Induced abortion is an indicator of access to, and quality of reproductive healthcare, but rates are relatively unknown in women with schizophrenia.

We examined whether women with schizophrenia experience increased induced abortion compared with those without schizophrenia, and identified factors associated with induced abortion risk.

In a population-based, repeated cross-sectional study (2011–2013), we compared women with and without schizophrenia in Ontario, Canada on rates of induced abortions per 1000 women and per 1000 live births. We then followed a longitudinal cohort of women with schizophrenia aged 15–44 years (n = 11 149) from 2011, using modified Poisson regression to identify risk factors for induced abortion.

Women with schizophrenia had higher abortion rates than those without schizophrenia in all years (15.5–17.5 v. 12.8–13.6 per 1000 women; largest rate ratio, 1.33; 95% CI 1.16–1.54). They also had higher abortion ratios (592–736 v. 321–341 per 1000 live births; largest rate ratio, 2.25; 95% CI 1.96–2.59). Younger age (<25 years; adjusted relative risk (aRR), 1.84; 95% CI 1.39–2.44), multiparity (aRR 2.17, 95% CI 1.66–2.83), comorbid non-psychotic mental illness (aRR 2.15, 95% CI 1.34–3.46) and substance misuse disorders (aRR 1.85, 95% CI 1.47–2.34) were associated with increased abortion risk.

These results demonstrate vulnerability related to reproductive healthcare for women with schizophrenia. Evidence-based interventions to support optimal sexual health, particularly in young women, those with psychiatric and addiction comorbidity, and women who have already had a child, are warranted.

Background: Evidence suggests that cannabis use may be associated with suicidality in adolescence. Nevertheless, very few studies have assessed this association in low- and middle-income countries (LMICs). In this cross-sectional survey, we investigated the association of cannabis use and suicidal attempts in adolescents from 21 LMICs, adjusting for potential confounders.

Method: Data from the Global school-based Student Health Survey was analyzed in 86,254 adolescents from 21 countries [mean (SD) age = 13.7 (0.9) years; 49.0% girls]. Suicide attempts during past year and cannabis during past month and lifetime were assessed. Multivariable logistic regression analyses were conducted.

Results: The overall prevalence of past 30-day cannabis use was 2.8% and the age-sex adjusted prevalence varied from 0.5% (Laos) to 37.6% (Samoa), while the overall prevalence of lifetime cannabis use was 3.9% (range 0.5%–44.9%). The overall prevalence of suicide attempts during the past year was 10.5%. Following multivariable adjustment to potential confounding variables, past 30-day cannabis use was significantly associated with suicide attempts (OR = 2.03; 95% CI: 1.42–2.91). Lifetime cannabis use was also independently associated with suicide attempts (OR = 2.30; 95% CI: 1.74–3.04).

Conclusion: Our data indicate that cannabis use is associated with a greater likelihood for suicide attempts in adolescents living in LMICs. The causality of this association should be confirmed/refuted in prospective studies to further inform public health policies for suicide prevention in LMICs.

Discrepancies between population-based estimates of the incidence of psychotic disorder and the treated incidence reported by early psychosis intervention (EPI) programs suggest additional cases may be receiving services elsewhere in the health system. Our objective was to estimate the incidence of non-affective psychotic disorder in the catchment area of an EPI program, and compare this to EPI-treated incidence estimates.

We constructed a retrospective cohort (1997–2015) of incident cases of non-affective psychosis aged 16–50 years in an EPI program catchment using population-based linked health administrative data. Cases were identified by either one hospitalization or two outpatient physician billings within a 12-month period with a diagnosis of non-affective psychosis. We estimated the cumulative incidence and EPI-treated incidence of non-affective psychosis using denominator data from the census. We also estimated the incidence of first-episode psychosis (people who would meet the case definition for an EPI program) using a novel approach.

Our case definition identified 3245 cases of incident non-affective psychosis over the 17-year period. We estimate that the incidence of first-episode non-affective psychosis in the program catchment area is 33.3 per 100 000 per year (95% CI 31.4–35.1), which is more than twice as high as the EPI-treated incidence of 18.8 per 100 000 per year (95% CI 17.4–20.3).

Case ascertainment strategies limited to specialized psychiatric services may substantially underestimate the incidence of non-affective psychotic disorders, relative to population-based estimates. Accurate information on the epidemiology of first-episode psychosis will enable us to more effectively resource EPI services and evaluate their coverage.

Involuntary admissions to psychiatric hospitals are common; however, research examining the trends in prevalence over time and predictors is limited.

To examine trends in prevalence and risk factors for involuntary admissions in Ontario, Canada.

We conducted an analysis of all mental health bed admissions from 2009 to 2013 and assessed the association between patient sociodemographics, service utilisation, pathway to care and severity characteristics for involuntary admissions using a modified Poisson regression.

We found a high and increasing prevalence of involuntary admissions (70.7% in 2009, 77.1% in 2013, 74.1% overall). Individuals with police contact in the prior week (risk ratio (RR) = 1.20) and immigrants both experienced greater likelihood of being involuntarily admitted, regardless of control for other characteristics (RR = 1.07) (both P < 0.0001).

We identified numerous modifiable and non-modifiable risk factors for involuntary admissions. The prevalence of involuntary admissions was high, linearly increasing over time.

The authors have completed the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported. This study was conducted using funding entirely from public sources. P.K. has received operational support via an Ontario Ministry of Health and Long-Term Care (MOHLTC) Health Services Research Fund Capacity Award to support this project. The Institute for Clinical Evaluative Sciences (ICES) is funded by the Ontario MOHLTC. The study results and conclusions are those of the authors, and should not be attributed to any of the funding agencies or sponsoring agencies. No endorsement by ICES or the Ontario MOHLTC is intended or should be inferred. All decisions regarding study design, publication, and data analysis were made independent of the funding agencies.

Up to 13% of psychiatric patients are readmitted shortly after discharge. Interventions that ensure successful transitions to community care may play a key role in preventing early readmission.

To describe and evaluate interventions applied during the transition from in-patient to out-patient care in preventing early psychiatric readmission.

Systematic review of transitional interventions among adults admitted to hospital with mental illness where the study outcome was psychiatric readmission.

The review included 15 studies with 15 non-overlapping intervention components. Absolute risk reductions of 13.6 to 37.0% were observed in statistically significant studies. Effective intervention components were: pre- and post-discharge patient psychoeducation, structured needs assessments, medication reconciliation/education, transition managers and in-patient/out-patient provider communication. Key limitations were small sample size and risk of bias.

Many effective transitional intervention components are feasible and likely to be cost-effective. Future research can provide direction about the specific components necessary and/or sufficient for preventing early psychiatric readmission.