Commentary on Degenhardt et al. (2018): Cause or consequence? Disentangling the relationship between psychosis and substance use

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.

Childhood adversity increases risk of psychotic experiences in patients with substance use disorder

INTRODUCTION

Adverse childhood experiences (ACEs) increase the risk of psychotic experiences (PE), but little is known about heterogeneities of this association in different developmental stages, dimensions, or whether they are affected by substance use disorder (SUD). This study examines the association between different types of ACEs at various developmental stages and lifetime PE in patients with SUD in Chile.

METHODS

We included 399 consenting adults in outpatient or residential SUD treatment programs. Sociodemographic data and information about PE and ACEs were obtained by trained clinical psychologists.

RESULTS

Patients reporting PE experienced more ACEs compared to patients without PE (4.2 versus 3.4). They also experienced more complex adversities (41.8% versus 25.1%), had more psychiatric comorbidities (85% versus 70.4%), and reported using more substances (mean 4.5 versus 3.9). Adjusted association between ACEs and PE showed the highest OR for arrests (1.88), sexual abuse (1.81), alcohol abuse by parents (1.48), school exclusion (1.39), foster or residential care (18.3).

CONCLUSION

Early exposure to ACEs is a risk factor for later PE among patients with SUD. Type of ACE and the period when they occurred is important, suggesting the existence of critical periods where the individual is more susceptible to adverse environmental stimuli.

Are psychotic-like experiences related to a discontinuation of cannabis consumption in young adults?

OBJECTIVE

To assess changes in cannabis use in young adults as a function of psychotic-like experiences.

METHOD

Participants were initially recruited at age 14 in high schools for the longitudinal IMAGEN study. All measures presented here were assessed at follow-ups at age 19 and at age 22, respectively. Perceived stress was only assessed once at age 22. Ever users of cannabis (N = 552) gave qualitative and quantitative information on cannabis use and psychotic-like experiences using the Community Assessment of Psychic Experiences (CAPE). Of those, nearly all n = 549 reported to have experienced at least one psychotic experience of any form at age 19.

RESULTS

Mean cannabis use increased from age 19 to 22 and age of first use of cannabis was positively associated with a change in cannabis use between the two time points. Change in cannabis use was not significantly associated with psychotic-like experiences at age 19 or 22. In exploratory analysis, we observed a positive association between perceived stress and the experience of psychotic experiences at age 22.

CONCLUSION

Age of first use of cannabis influenced trajectories of young cannabis users with later onset leading to higher increase, whereas the frequency of psychotic-like experiences was not associated with a change in cannabis use. The observed association between perceived stress and psychotic-like experiences at age 22 emphasizes the importance of stress experiences in developing psychosis independent of cannabis use.

Association between polygenic liability for schizophrenia and substance involvement: A nationwide population-based study in Taiwan

Schizophrenia and substance involvement frequently co-occur in individuals, and a bidirectional relationship between the two has been proposed; shared underlying genetic factors could be an alternative explanation. This study investigated the genetic overlap between schizophrenia and substance involvement, including tobacco, alcohol and betel nut use. The study subjects were recruited from the Taiwan Biobank, and genome-wide genotyping data was available for 18 327 participants without schizophrenia. We calculated the Psychiatric Genomics Consortium-derived polygenic risk score (PRS) for schizophrenia in each participant. The significance of the schizophrenia PRS associated with substance involvement was evaluated using a regression model with adjustments for gender, age and population stratification components. The modified effect of gender or birth decade was also explored. The schizophrenia PRS was positively associated with lifetime tobacco smoking in women (OR in per SD increase in PRS = 1.12 with 95% CI 1.04-1.20, P = .002), but not in men (OR = 0.99 with 95% CI 0.95-1.04, P = .74), and the gender-PRS interaction reached significance (P = .006). The OR between PRS and lifetime tobacco smoking increased with the birth decade (P of birth decade-PRS interaction = .0002). In women, OR increased from 0.97 (P = .85) for subjects with a birth decade before 1950 to 1.21 (P = .04) for subjects with a birth decade after 1980; in men, the corresponding OR increased from 0.88 (P = .04) to 1.13 (P = .11). There was no association between schizophrenia PRS and alcohol/betel nut use phenotypes. This study provides evidence for the genetic overlap between schizophrenia and tobacco use in women, and this overlap was stronger in the younger population.