Association between alcohol, cannabis, and other illicit substance abuse and risk of developing schizophrenia: a nationwide population based register study

Factors associated with improved outcomes in the first psychotic episode at a specialized outpatient clinic in northeastern Brazil

OBJECTIVES

The present study aimed to evaluate data from patients admitted to the first-episode psychotic (FEP) outpatient clinic at the Hospital of Clinics of the Federal University of Pernambuco from July 2018 to July 2021, seeking to identify factors related to better clinical outcomes.

METHODS

This study was conducted using a convenience sample, including all patients between 15 and 65 years of age who were admitted to the FEP outpatient clinic from July 2018 to July 2021. Descriptive statistical analysis was performed using mean and standard deviation or median and interquartile range for continuous quantitative variables, and absolute number/percentage for qualitative variables. Paired T-test, a parametric test, was used to compare PANSS scores upon admission and after 6 months. Spearman's correlation test was employed to assess the correlation between duration of untreated psychosis (DUP) and treatment response with other variables.

RESULTS

The sample consisted of 85.3% male individuals, with 50% of patients aged between 19 and 30 years, and 82% residing in the metropolitan area of Recife. Seventy percent of patients responded to the treatment implemented by the outpatient clinic, and only 30% required psychiatric hospitalization within 6 months of follow-up. The majority of patients had a history of psychoactive substance use (82.4%); however, the use of these substances did not impact the prognosis within the analysed sample. The median DUP was 4 weeks, and a shorter DUP was associated with a lower probability of psychiatric hospitalization and a greater treatment response (reduction >50% in PANSS).

CONCLUSION

A shorter DUP was associated with a lower likelihood of psychiatric hospitalization and a greater treatment response. Furthermore, the specialized early psychosis outpatient clinic itself appears to yield positive outcomes, as 70% of the treated patients exhibited a positive treatment response.

Use of antipsychotic medication, benzodiazepines, and psychiatric hospitalization in cannabis-related versus cannabis-unrelated schizophrenia - a nationwide, register-based cohort study

BACKGROUND

Evidence suggests that cannabis may be a causal factor for development of schizophrenia. We aimed to investigate whether use of antipsychotic medication, benzodiazepines, and psychiatric service use differs among patients with schizophrenia depending on whether psychosis was precipitated by a diagnosis of cannabis use disorder (CUD).

METHODS

We utilized the nationwide Danish registries to identify all individuals with an incident diagnosis of schizophrenia from 1995 to 2016. We also collected information on whether first CUD diagnosis preceded schizophrenia and thus defined a group of potentially cannabis-related schizophrenia. We compared the cannabis-related schizophrenia group both with all non-cannabis-related patients with schizophrenia and with non-cannabis-related patients with schizophrenia that were propensity-score matched to cases using a range of potentially confounding variables.

RESULTS

We included 35 714 people with incident schizophrenia, including 4116 (11.5%) that were cannabis-related. In the unmatched-comparison analyses, there were no clear differences over time in use of antipsychotics and benzodiazepines related to whether the diagnosis of schizophrenia was cannabis-related. After propensity-score matching, use of antipsychotics and benzodiazepines was significantly lower among cannabis-related cases of schizophrenia. In the unmatched comparison, the cannabis-related group had significantly more days admitted than the non-cannabis-related group. This was markedly attenuated after propensity-score matching.

CONCLUSIONS

Our findings indicate the importance of considering cannabis-related cases of schizophrenia as a potentially distinct disorder in terms of prognosis. It is unclear, however, if these differences are due to different biological types of schizophrenia being compared or if they rather indicate behavioral differences such as reduced adherence and treatment-seeking.

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.

Transition to Schizophrenia Spectrum Disorder Following Emergency Department Visits Due to Substance Use With and Without Psychosis

Importance

Episodes of substance-induced psychosis are associated with increased risk of developing a schizophrenia spectrum disorder. However, there are limited data on the transition risk for substance use without psychosis.

Objectives

To quantify the risk of transition to schizophrenia spectrum disorder following an incident emergency department (ED) visit for (1) substance-induced psychosis and (2) substance use without psychosis and to explore factors associated with transition.

Design, Settings, and Participants

A population-based retrospective cohort study (January 2008 to March 2022) of all individuals, aged 14 to 65 years, in Ontario, Canada, with no history of a psychotic disorder. Individuals with incident ED visits for substance use with and without psychosis were compared with members of the general population.

Main Outcomes and Measures

Transition to schizophrenia spectrum disorder using a chart-validated algorithm. Associations between ED visits for substance use and subsequent transition were estimated using cause-specific hazard models.

Results

The study included 9 844 497 individuals, aged 14 to 65 years (mean [SD] age, 40.2 [14.7] years; 50.2% female) without a history of psychosis. There were 407 737 individuals with an incident ED visit for substance use, of which 13 784 (3.4%) ED visits were for substance-induced psychosis. Individuals with substance-induced psychosis were at a 163-fold (age- and sex-adjusted hazard ratio [aHR], 163.2; 95% CI, 156.1-170.5) increased risk of transitioning, relative to the general population (3-year risk, 18.5% vs 0.1%). Individuals with an ED visit for substance use without psychosis had a lower relative risk of transitioning (aHR, 9.8; 95% CI, 9.5-10.2; 3-year risk, 1.4%), but incurred more than 3 times the absolute number of transitions (9969 vs 3029). Cannabis use had the highest transition risk among visits with psychosis (aHR, 241.6; 95% CI, 225.5-258.9) and the third-highest risk among visits without psychosis (aHR, 14.3; 95% CI, 13.5-15.2). Younger age and male sex were associated with a higher risk of transition, and the risk of male sex was greater in younger compared with older individuals, particularly for cannabis use.

Conclusions and Relevance

The findings of this cohort study suggest that ED visits for substance use were associated with an increased risk of developing a schizophrenia spectrum disorder. Although substance-induced psychoses had a greater relative transition risk, substance use without psychosis was far more prevalent and resulted in a greater absolute number of transitions. Several factors were associated with higher transition risk, with implications for counseling and early intervention.

Perturbation of 3D nuclear architecture, epigenomic aging and dysregulation, and cannabinoid synaptopathy reconfigures conceptualization of cannabinoid pathophysiology: part 2-Metabolome, immunome, synaptome

The second part of this paper builds upon and expands the epigenomic-aging perspective presented in Part 1 to describe the metabolomic and immunomic bases of the epigenomic-aging changes and then considers in some detail the application of these insights to neurotoxicity, neuronal epigenotoxicity, and synaptopathy. Cannabinoids are well-known to have bidirectional immunomodulatory activities on numerous parts of the immune system. Immune perturbations are well-known to impact the aging process, the epigenome, and intermediate metabolism. Cannabinoids also impact metabolism via many pathways. Metabolism directly impacts immune, genetic, and epigenetic processes. Synaptic activity, synaptic pruning, and, thus, the sculpting of neural circuits are based upon metabolic, immune, and epigenomic networks at the synapse, around the synapse, and in the cell body. Many neuropsychiatric disorders including depression, anxiety, schizophrenia, bipolar affective disorder, and autistic spectrum disorder have been linked with cannabis. Therefore, it is important to consider these features and their complex interrelationships in reaching a comprehensive understanding of cannabinoid dependence. Together these findings indicate that cannabinoid perturbations of the immunome and metabolome are important to consider alongside the well-recognized genomic and epigenomic perturbations and it is important to understand their interdependence and interconnectedness in reaching a comprehensive appreciation of the true nature of cannabinoid pathophysiology. For these reasons, a comprehensive appreciation of cannabinoid pathophysiology necessitates a coordinated multiomics investigation of cannabinoid genome-epigenome-transcriptome-metabolome-immunome, chromatin conformation, and 3D nuclear architecture which therefore form the proper mechanistic underpinning for major new and concerning epidemiological findings relating to cannabis exposure.

Terminal type-specific cannabinoid CB1 receptor alterations in patients with schizophrenia: A pilot study

BACKGROUND

Individuals with schizophrenia are at elevated genetic risks for comorbid cannabis use, and often experience exacerbations of cognitive and psychotic symptoms when exposed to cannabis. These findings have led a number of investigators to examine cannabinoid CB1 receptor (CB1R) alterations in schizophrenia, though with conflicting results. We recently demonstrated the presence of CB1R in both excitatory and inhibitory boutons in the human prefrontal cortex, with differential levels of the receptor between bouton types. We hypothesized that the differential enrichment of CB1R between bouton types - a factor previously unaccounted for when examining CB1R changes in schizophrenia - may resolve prior discrepant reports and increase our insight into the effects of CB1R alterations on the pathophysiology of schizophrenia.

METHODS

Using co-labeling immunohistochemistry and fluorescent microscopy, we examined total CB1R levels and CB1R levels within excitatory (vGlut1-positive) and inhibitory (vGAT-positive) boutons of prefrontal cortex samples from ten pairs of individuals (nine male pairs and one female pair) diagnosed with schizophrenia and non-psychiatric comparisons.

RESULTS

Significantly higher total CB1R levels were found within samples from individuals with schizophrenia. Terminal type-specific analyses identified significantly higher CB1R levels within excitatory boutons in samples from individuals with schizophrenia relative to comparisons. In contrast, CB1R levels within the subset of inhibitory boutons that normally express high CB1R levels (presumptive cholecystokinin neuron boutons) were lower in samples from individuals with schizophrenia relative to comparison samples.

CONCLUSION

Given CB1R's role in suppressing neurotransmission upon activation, these results suggest an overall shift in excitatory and inhibitory balance regulation toward a net reduction of excitatory activity in schizophrenia.

Cannabis Use Disorder and Subsequent Risk of Psychotic and Nonpsychotic Unipolar Depression and Bipolar Disorder

Importance

Cannabis use is increasing worldwide and is suspected to be associated with increased risk of psychiatric disorders; however, the association with affective disorders has been insufficiently studied.

Objective

To examine whether cannabis use disorder (CUD) is associated with an increased risk of psychotic and nonpsychotic unipolar depression and bipolar disorder and to compare associations of CUD with psychotic and nonpsychotic subtypes of these diagnoses.

Design, Setting, and Participants

This prospective, population-based cohort study using Danish nationwide registers included all individuals born in Denmark before December 31, 2005, who were alive, aged at least 16 years, and living in Denmark between January 1, 1995, and December 31, 2021.

Exposure

Register-based diagnosis of CUD.

Main Outcome and Measures

The main outcome was register-based diagnosis of psychotic or nonpsychotic unipolar depression or bipolar disorder. Associations between CUD and subsequent affective disorders were estimated as hazard ratios (HRs) using Cox proportional hazards regression with time-varying information on CUD, adjusting for sex; alcohol use disorder; substance use disorder; having been born in Denmark; calendar year; parental educational level (highest attained); parental cannabis, alcohol, or substance use disorders; and parental affective disorders.

Results

A total of 6 651 765 individuals (50.3% female) were followed up for 119 526 786 person-years. Cannabis use disorder was associated with an increased risk of unipolar depression (HR, 1.84; 95% CI, 1.78-1.90), psychotic unipolar depression (HR, 1.97; 95% CI, 1.73-2.25), and nonpsychotic unipolar depression (HR, 1.83; 95% CI, 1.77-1.89). Cannabis use was associated with an increased risk of bipolar disorder in men (HR, 2.96; 95% CI, 2.73-3.21) and women (HR, 2.54; 95% CI, 2.31-2.80), psychotic bipolar disorder (HR, 4.05; 95% CI, 3.52-4.65), and nonpsychotic bipolar disorder in men (HR, 2.96; 95% CI, 2.73-3.21) and women (HR, 2.60; 95% CI, 2.36-2.85). Cannabis use disorder was associated with higher risk for psychotic than nonpsychotic subtypes of bipolar disorder (relative HR, 1.48; 95% CI, 1.21-1.81) but not unipolar depression (relative HR, 1.08; 95% CI, 0.92-1.27).

Conclusions and Relevance

This population-based cohort study found that CUD was associated with an increased risk of psychotic and nonpsychotic bipolar disorder and unipolar depression. These findings may inform policies regarding the legal status and control of cannabis use.

Alcohol drinking in male patients with chronic schizophrenia: prevalence and its relationship to clinical symptoms

Background

It is common practice to associate schizophrenia (SCZ) patients with substance use. The most commonly used substances in China are tobacco and alcohol. However, few studies have focused on alcohol consumption itself in patients with SCZ. Thus the purpose of this study was to detect the prevalence of alcohol use and associated clinical factors in Chinese patients with SCZ.

Methods

A total of 616 male inpatients who met the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for SCZ participated in this study. A detailed questionnaire, including data on alcohol consumption was used to collect demographic and clinical information on all patients. The five-factor model of the positive and negative syndrome scale (PANSS) was adopted to assess psychiatric symptoms.

Results

In this study, 31.49% of SCZ inpatients had a history of alcohol use, and 82.9% of these patients abstained from alcohol use after the onset of SCZ. Compared to nondrinkers, patients who drank were more likely to smoke (p = 0.004), more likely to have suicide attempts (p = 0.002) and suicidal ideation (p = 0.001), more severe positive (p < 0.001) and depressive symptoms (p = 0.034), but less severe negative symptoms (p = 0.04).

Conclusion

These findings suggest that alcohol use is common during the lifetime of SCZ patients and that alcohol use may be associated with clinical symptoms in SCZ patients.

Does a history of cannabis use influence onset and course of schizophrenia?

INTRODUCTION

While evidence strongly supports a causal effect of cannabis on psychosis, it is less clear whether the symptom pattern, clinical course, and outcomes differ in cases of schizophrenia with and without a background of cannabis use.

METHODS

Analysis of medical records from a longitudinal follow-up of Swedish conscripts with data on cannabis use in adolescence and subsequent incidence of schizophrenia. One hundred sixty patients with schizophrenia were assessed using the OPCRIT protocol. Cases were validated for diagnosis schizophrenia according to OPCRIT.

RESULTS

Patients with a cannabis history (n = 32), compared to those without (n = 128), had an earlier age at onset, a higher number of hospital admissions and a higher total number of hospital days. There was no significant difference in type of onset and clinical symptom profiles between the groups.

CONCLUSION

Our findings indicate that the disease burden of schizophrenia is greater in individuals who use cannabis during adolescence. Strengthening evidence on causality and teasing out long-term effects of pre-illness cannabis use from continued post-illness has clinical implications for improving schizophrenia outcomes.

Terminal type-specific cannabinoid CB1 receptor alterations in patients with schizophrenia: a pilot study

Background

Individuals with schizophrenia are at elevated genetic risks for comorbid cannabis use, and often experience exacerbations of cognitive and psychotic symptoms when exposed to cannabis. These findings have led a number of investigators to examine cannabinoid CB1 receptor (CB1R) alterations in schizophrenia, though with conflicting results. We recently demonstrated the presence of CB1R in both excitatory and inhibitory boutons in the human prefrontal cortex, with differential levels of the receptor between bouton types. We hypothesized that the differential enrichment of CB1R between bouton types - a factor previously unaccounted for when examining CB1R changes in schizophrenia - may resolve prior discrepant reports and increase our insight into the effects of CB1R alterations on the pathophysiology of schizophrenia.

Methods

Using co-labeling immunohistochemistry and fluorescent microscopy, we examined total CB1R levels and CB1R levels within excitatory (vGlut1-positive) and inhibitory (vGAT-positive) boutons of prefrontal cortex samples from ten pairs of individuals diagnosed with schizophrenia and non-psychiatric comparisons.

Results

Significantly higher total CB1R levels were found within samples from individuals with schizophrenia. Terminal type-specific analyses identified significantly higher CB1R levels within excitatory boutons in samples from individuals with schizophrenia relative to comparisons. In contrast, CB1R levels within the subset of inhibitory boutons that normally express high CB1R levels (presumptive cholecystokinin neuron boutons) were lower in samples from individuals with schizophrenia relative to comparison samples.

Conclusion

Given CB1R's role in suppressing neurotransmission upon activation, these results suggest an overall shift in excitatory and inhibitory balance regulation toward a net reduction of excitatory activity in schizophrenia.

Prevalence, service use and clinical correlates of hallucinations and delusions in an out-patient population from India

BACKGROUND

Despite the persistent public health problem of positive psychotic symptoms, understanding of symptom specific prevalence rates, clinical correlates and service utilisation are sparse.

AIMS

The current study aimed to establish prevalence, clinical and service utilisation correlates of hallucinations and delusions in people accessing outpatient clinics in Tamil Nadu, India.

METHODS

Secondary patient data from outpatient clinics, over a 12-month period, in 2016, was used for analysis (N = 917). Based on the presence of positive psychotic symptoms (PPSx), the sample was divided into four groups for analysis- hallucinations-only (H), delusions-only (D), both hallucinations and delusions (HD) and neither PPSx (N-PPSx).

RESULTS

Findings indicate that the most prevalent PPSx were hallucinations (10.7%) however, barriers to service utilisation and clinical correlates were associated predominantly with the D and the HD group; as was severe work impairment. Yet, this group was most likely to remain with psychiatric services. Lastly, diagnostic challenges were apparent within the sample.

CONCLUSIONS

The study revealed that despite more barriers to service utilisation, persons with PPSx remain in contact with services. Yet prognosis remains only moderate at best, indicating other mediating and underlying factors impeding recovery may be interplaying and, therefore, a need for enhanced biopsychosocial approaches.

Diagnostic progression to schizophrenia: A nationwide cohort study of 11 170 adolescents and young adults with autism spectrum disorder

AIMS

Previous studies have suggested an increased risk of developing schizophrenia later in life in children with autism spectrum disorder (ASD). This study aims to investigate the diagnosis stability and the potential predictors for progression to schizophrenia in ASD.

METHODS

We recruited 11 170 adolescents (10-19 years) and young adults (20-29 years) with ASD between 2001 and 2010. They were followed up to the end of 2011 to identify newly diagnosed schizophrenia. The Kaplan-Meier method and Cox regression with age as a time scale were employed to estimate incidence rates and the significance of candidate predictors.

RESULTS

The progression rate from ASD to schizophrenia was 10.26% for 10 years of follow-up. Among 860 progressors, 580 (67.44%) occurred within the first 3 years after a diagnosis of ASD. The identified predictors were age (reported as hazard ratio with 95% confidence interval: 1.13; 1.11-1.15), depressive disorder (1.36; 1.09-1.69), alcohol use disorder (3.05; 2.14-4.35), substance use disorder (1.91; 1.18-3.09), cluster A personality disorder (2.95; 1.79-4.84), cluster B personality disorder (1.86; 1.05-3.28), and a family history of schizophrenia (2.12; 1.65-2.74).

CONCLUSION

More than two-thirds of the progressors developed schizophrenia within the first 3 years. Demographic characteristics, physical and psychiatric comorbidities, and psychiatric family history were significant predictors of progression.

Consensus paper of the WFSBP task force on cannabis, cannabinoids and psychosis

OBJECTIVES

The liberalisation of cannabis laws, the increasing availability and potency of cannabis has renewed concern about the risk of psychosis with cannabis.

METHODS

The objective of the WFSBP task force was to review the literature about this relationship.

RESULTS

Converging lines of evidence suggest that exposure to cannabis increases the risk for psychoses ranging from transient psychotic states to chronic recurrent psychosis. The greater the dose, and the earlier the age of exposure, the greater the risk. For some psychosis outcomes, the evidence supports some of the criteria of causality. However, alternate explanations including reverse causality and confounders cannot be conclusively excluded. Furthermore, cannabis is neither necessary nor sufficient to cause psychosis. More likely it is one of the multiple causal components. In those with established psychosis, cannabis has a negative impact on the course and expression of the illness. Emerging evidence also suggests alterations in the endocannabinoid system in psychotic disorders.

CONCLUSIONS

Given that exposure to cannabis and cannabinoids is modifiable, delaying or eliminating exposure to cannabis or cannabinoids, could potentially impact the rates of psychosis related to cannabis, especially in those who are at high risk for developing the disorder.

Polygenic risk scores for schizophrenia and major depression are associated with socio-economic indicators of adversity in two British community samples

Schizophrenia (SCZ) and major depressive disorder (MDD) are complex psychiatric disorders which contribute substantially to the global burden of disease. Both psychopathologies are heritable with some genetic overlap between them. Importantly, SCZ and MDD have also been found to be associated with environmental risk factors. However, rather than being independent of genetic influences, exposure to environmental risk factors may be under genetic control, known as gene-environment correlation (rGE). In this study we investigated rGE in relation to polygenic risk scores for SCZ and MDD in adults, derived from large genome-wide association studies, across two different British community samples: Understanding Society (USoc) and the National Child Development Study (NCDS). We tested whether established environmental risk factors for SCZ and/or MDD are correlated with polygenic scores in adults and whether these associations differ between the two disorders and cohorts. Findings partially overlapped between disorders and cohorts. In NCDS, we identified a significant correlation between the genetic risk for MDD and an indicator of low socio-economic status, but no significant findings emerged for SCZ. In USoc, we replicated associations between indicators of low socio-economic status and the genetic propensity for MDD. In addition, we identified associations between the genetic susceptibility for SCZ and being single or divorced. Results across both studies provide further evidence that the genetic risk for SCZ and MDD were associated with common environmental risk factors, specifically MDD's association with lower socio-economic status.

A retrospective analysis of substance use among female psychiatric patients in Saudi Arabia

Objective

This study investigated the prevalence of substance use (SU), and its risk factors, among women attending psychiatric outpatients center in Saudi Arabia.

Design

A retrospective cross-sectional design.

Materials and methods

We reviewed outpatients' records of 200 female patients with a history of SU from a psychiatric unit in Jeddah, Saudi Arabia from December 2018 to February 2019. The researchers developed the pro forma, and 2 psychiatrists and a family medicine physician validated the form.

Results

The most common and widely used were psychoactive substances (58%), followed by central nervous system (CNS) depressants (22%), and finally cannabinols (9.5%). Overall, the highest substance use was the amphetamine-cannabis-nicotine (ACN) representing nearly half of the illicit items (46.6%), followed by heroine-alcohol-benzodiazepine (16.4%), and with the lowest being benzodiazepine-nicotine (1.7%). There was a significant difference between the single substance and multiple substance use in terms of age (p = 0.001), smoking behavior (p = 0.001), patients past history (p = 0.005), and age of the patient at the start of drug use (p = 0.005).

Conclusion

Although the prevalence of substance use among women is low in Saudi Arabia, screening of substance use disorders risks and building a rehabilitation program to control drug dependence are needed.

Alcohol use history increases the likelihood of suicide behavior among male chronic patients with schizophrenia in a Chinese population

AIMS

This study was designed to detect the association between the history of alcohol drinking and suicidality in schizophrenia (SCZ) inpatients in a Chinese population.

METHODS

We recruited 616 male SCZ inpatients and collected demographic and clinical data. Five-factor model of the Positive and Negative Syndrome Scale (PANSS) was used to assess their psychopathological symptoms.

RESULTS

Our results showed that 31.33% of SCZ patients had a history of alcohol drinking. They had higher rates of lifetime suicide attempt and suicidal ideation than those without a history of alcohol drinking. Moreover, patients with a history of drinking were more likely to attempt suicide (14.51% vs. 7.09%; χ²  = 7.70, df = 1, p = 0.006), with an odds ratio (OR) of 2.22 and have suicidal ideation (29.02% vs. 17.49%; χ²  = 9.89, df = 1, p = 0.002), with an OR of 1.93. In addition, patients who used to drink alcohol were more likely to be smokers and had more severe positive and depressive symptoms (all p < 0.05).

CONCLUSIONS

Our study indicates that history of alcohol drinking may increase the prevalence of lifetime suicide attempt and suicidal ideation in male patients with chronic SCZ. Moreover, the history of alcohol drinking may be associated with some demographic data and clinical symptoms.

Multifactorial Causes of Paranoid Schizophrenia With Auditory-Visual Hallucinations in a 31-Year-Old Male With History of Traumatic Brain Injury and Substance Abuse

Schizophrenia is a chronic psychiatric disorder that classically presents with distortions of thought, behavior, and perceptions that are often misdiagnosed. One difficulty in diagnosing schizophrenia is due to its phenotypically heterogeneous condition that can be precipitated by a combination of genetic, epigenetic, and environmental factors. The prevalence of schizophrenia is roughly 1%, but it is often misdiagnosed. Possible differential diagnoses include depression or bipolar disorder with psychosis, psychosis due to a medical condition, schizotypal and schizoid personality disorders, and neurocognitive disorders. 

In this case report, a 31-year-old male presents with thoughts of suicide following a recent exacerbation of his hallucinations. On presentation, the patient presented with a historical diagnosis of “paranoid schizophrenia” as well as a history of traumatic brain injury (TBI), poly-substance use disorder, and a family history of schizophrenia. This case serves to highlight the difficulties of making an accurate diagnosis and providing evidenced-based treatment.

Co-occurring Mental Disorders in Transitional Aged Youth With Substance Use Disorders - A Narrative Review

Adolescence and emerging adulthood are often referred to as youth. Transitional psychiatry addresses this target group, which considers patients between 15 and 25 years of age. Substance use usually begins and peaks at this stage of life. Psychiatric disorders, foremost attention-deficit/hyperactivity disorder, and affective disorders, conduct disorders, and first-episodes psychosis frequently appear in early life stages. This review aims to provide a broad overview of transitional-aged youth's most common psychiatric comorbidities with substance use disorders. A literature search was conducted in Embase and Pubmed, and the main findings are described narratively. We present main findings for the following comorbidities: attention-deficit/hyperactivity disorder, conduct disorder, personality disorders, affective disorders, psychotic disorders, and the phenomena of overdose and suicidality. In conclusion, co-occurring mental health disorders are common and appear to facilitate the development of substance use disorders and exacerbate their overall course. Substance use also affects the severity and course of comorbid psychiatric disorders. Overall, data on transition-age youth with substance use disorders are highly inconsistent. Universal screening and treatment guidelines do not yet exist but should be aimed for in the future.

Cannabis-based medicines and medical cannabis for patients with neuropathic pain and other pain disorders: Nationwide register-based pharmacoepidemiologic comparison with propensity score matched controls

BACKGROUND

Neuropathic pain and other pain disorders have received attention as potential indications for use of cannabis-based medicines or medical cannabis (CBM/MC). Evidence regarding the efficacy and safety of CBM/MC for pain disorders is, however, insufficient. Denmark introduced a pilot programme of medical cannabis in January 2018. We aimed to evaluate efficacy, safety, and non-specific effects of CBM/MC used under the pilot programme compared with controls.

METHODS

We conducted a nationwide register-based cohort study in Denmark, identifying all individuals redeeming at least one prescription for CBM/MC for either neuropathic pain (n = 1817) or other and unspecified pain disorders (n = 924), and to match one control to each case using propensity score matching.

RESULTS

Among both patient groups, users of THC used more opioids during follow-up than controls. Among patients with neuropathic pain, however, users of either CBD, THC, or combined CBD + THC used less gabapentin than controls. Users of all three classes of CBM/MC were hospitalized fewer days than controls among neuropathic-pain patients but not among patients with other or unspecified pain disorders.

CONCLUSIONS

CBM/MC were generally safe and even displayed some positive effects among patients with neuropathic pain. We conclude that CBM/MC are safe and possibly efficacious for patients with neuropathic pain but not patients with other pain disorders.

SIGNIFICANCE

Patients with neuropathic pain may benefit from treatment with cannabis-based medicines or medical cannabis (CBM/MC), particularly in terms of reduced use of gabapentin and fewer days admitted to hospitals, compared with propensity score matched controls. CBM/MC did not, however, reduce the use of opioids. We did not find evidence that CBM/MC were effective for patients with other pain disorders.

Development Over Time of the Population-Attributable Risk Fraction for Cannabis Use Disorder in Schizophrenia in Denmark

IMPORTANCE

Cannabis use and potency of cannabis have increased during the past 2 decades. If the association between cannabis use and schizophrenia is causal, this should be reflected in an increase in the proportion of cases of schizophrenia being attributable to cannabis, the population-attributable risk fraction (PARF).

OBJECTIVE

To determine whether the PARF for cannabis use disorder in schizophrenia has increased over time.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide, register-based historical prospective cohort study included all people in Denmark born before December 31, 2000, who were alive and 16 years or older at some point from January 1, 1972, to December 31, 2016. Data analysis was performed from August 2020 to April 2021.

EXPOSURE

Diagnosis of cannabis use disorder.

MAIN OUTCOMES AND MEASURES

Diagnosis of schizophrenia, with estimated PARF of cannabis use disorder in schizophrenia from 1972 to 2016.

RESULTS

A total of 7 186 834 individuals were included in the analysis, including 3 595 910 women (50.0%) and 3 590 924 men (50.0%). The adjusted hazard ratio for schizophrenia fluctuated at approximately 4 (with 95% CIs ranging from approximately 3 to 6) throughout most of the study period when people diagnosed with cannabis use disorder were compared with those without cannabis use disorder. The PARF of cannabis use disorder in schizophrenia also fluctuated, but with clear evidence of an increase from 1995 (when the PARF was relatively stable around 2.0%, with a 95% CI of approximately 0.3% to either side) until reaching some stability around 6.0% to 8.0% (with a 95% CI of approximately 0.5% to either side) since 2010.

CONCLUSIONS AND RELEVANCE

The results from these longitudinal analyses show the proportion of cases of schizophrenia associated with cannabis use disorder has increased 3- to 4-fold during the past 2 decades, which is expected given previously described increases in the use and potency of cannabis. This finding has important ramifications regarding legalization and control of use of cannabis.

Medical cannabis and cannabis-based medicine show both potential efficacy and potential harms: Cross-sectional comparison with controls on self-rated and interviewer-rated outcomes within the Danish pilot program on medical cannabis

BACKGROUND AND PURPOSE

Denmark launched a pilot program of medical cannabis in January 2018. The aim was to establish whether medical cannabis and cannabis-based medicine (MC/CBM) were superior and safe compared to conventional treatment, regardless of the indications for which people received such medication.

MATERIALS AND METHODS

People (cases) were identified who had redeemed at least one prescription of MC/CBM according to the nationwide, unselected Danish registers. These were propensity-score matched to controls with the same indications who had not used MC/CBM. Potential participants were contacted electronically, and if willing to participate filled in various survey instruments online. Participants were also interviewed in person in order to investigate symptoms of depression, anxiety, and to assess cognitive levels. Different sets of analyses were conducted, handling potential confounders in different ways.

RESULTS

In the primary analyses, cases were more satisfied with their treatment than were controls (mean (SD) 29.2 (4.8) versus 26.5 (4.5) on the CSQ, p = 0.006), and scored lower on depression (3.3 (3.0) versus 4.6 (2.9), p = 0.03). Cases reported higher levels of pain than controls when measured on the SF-36 bodily-pain subdomain (36.3 (23.0) versus 48.7 (30.1), p = 0.01). There were indications of worse symptoms of multiple sclerosis in cases compared to controls. Reported side-effects were generally mild.

CONCLUSION

Both potential effects and harms of MC/CBM were observed. Randomized trials are required to establish if these are true effects and harms, or due to confounding by indication.

Substance use in youth at-risk for serious mental illness

AIM

The aim of this paper is to describe the substance use of participants who are at-risk for serious mental illness (SMI).

METHOD

The Canadian Psychiatric Risk and Outcome study (PROCAN) is a two-site study of 243 youth and young adults aged 13 to 25 years, categorized into four groups: healthy controls (n = 42), stage 0 (asymptomatic individuals with risk of SMI typically family high risk; n = 41), stage 1a (distress disorder or mild symptoms of anxiety or depression; n = 53) and stage 1b (attenuated syndromes, including bipolar disorder or psychosis; n = 107). Substance use measures were administered at baseline, 6- and 12-months.

RESULTS

At baseline, the most commonly reported substance used in the past month was alcohol (43.6%), followed by cannabis (14.4%) and tobacco (12.4%). There were no significant group differences in use. 42.4% of all participants reported ever using cannabis in their lifetime, whereas 21.4% reported currently using cannabis. There were no group differences in ever having used cannabis. Regarding lifetime substance abuse disorders, cannabis use disorder (5.7%) and alcohol use disorder (4.5%) were the most common and more often reported in stage 1b participants relative to other groups. Furthermore, alcohol, cannabis and tobacco use remained relatively consistent at 6- and 12-month follow-ups when compared to baseline use.

CONCLUSION

Alcohol was the most commonly used substance followed by cannabis and tobacco. Although substance use did not differ between those at different stages of risk, overall prevention strategies are still warranted for youth at-risk for SMI, especially those who are more symptomatic and potentially at greater risk of developing an SMI.

The impact of study design on schizophrenia incidence estimates: A systematic review of Northern European studies 2008-2019

The best estimates of the incidence of schizophrenia range more than 25-fold from 3 to 80 per 100,000 person-years. To what extent do differences in study design explain this wide variation? We selected all studies published between 2008-2019 reporting the incidence of schizophrenia in general populations of Northern Europe. We identified 17 estimates covering 85 million person-years and more than 15,000 individual cases. The estimates ranged from 4-72 per 100,000 person-years (median 30; interquartile range 13-41). We classified the estimates in terms of three study design factors (coverage of services, time frame, and diagnostic quality) and two population factors (urbanicity and age). A meta-regression model of the three design factors, using the two population factors as covariates, explained 91% of between-study variation. Studies performed in general psychiatric services reported similar estimates [incidence rate ratio 1.12 (95% confidence interval 0.88 to 1.43)] to those performed in specialized services. But studies applying a cumulative time frame to diagnosis reported fourfold higher estimates [4.04 (3.14 to 5.2)] than those applying a first-contact time frame. And studies based on clinical diagnoses reported lower estimates [0.55 (0.43 to 0.72)] than those based on standardized research diagnoses. The three study design factors by themselves explained 67% of between-study variation. When comparing incidence rates from different populations, distorsions arising from differences in study design can eclipse differences caused by schizophrenia risk factors, such as gender, age or migrant status.

Annual incidence of cannabis-induced psychosis, other substance-induced psychoses and dually diagnosed schizophrenia and cannabis use disorder in Denmark from 1994 to 2016

BACKGROUND

Worldwide, cannabis is the most used illegal substance, and the use of cannabis has increased over the years. An increase in the level of tetrahydrocannabinol (THC) in cannabis has also been seen. It is currently unclear whether this has led to an increase in the incidence of cannabis-induced psychosis. We aimed to investigate (1) the development of incidence of cannabis-induced psychosis over time compared with other substance-induced psychoses and (2) the development of incident cases of cannabis-induced psychosis over time compared with dual diagnosis defined as schizophrenia and a cannabis use disorder.

METHOD

Data on psychiatric diagnoses were extracted from the Danish Psychiatric Central Research Register and summarized per year as both absolute incidence (number of cases) and incidence rates per 100 000 person years.

RESULTS

The incidence rate of cannabis-induced psychosis increased steadily from 2.8 per 100 000 person years in 2006 to 6.1 per 100 000 person years in 2016. There was a corresponding increase in dual diagnosis with schizophrenia and cannabis use disorder, but a decrease in alcohol-induced psychosis. The data showed no trend in the other substance-induced psychosis investigated in this thesis.

CONCLUSION

The increase in cannabis-induced psychosis follows both the increase in the level of THC in cannabis, and the increase in cannabis use. The change in diagnostic practice does not appear to explain the increase in incidence of cannabis-induced psychosis.

Outpatient prescribing of opioids to adults diagnosed with mental disorders in the United States

BACKGROUND

Adults with mood and anxiety disorders have an increased likelihood of being prescribed opioids. The influence of other mental disorders, such as psychotic and attention disorders, on opioid prescribing patterns is less known.

METHODS

We studied a population-representative sample of 166,927 outpatient visits for adults with painful conditions from the 2002-2016 National Ambulatory Medical Care Survey and the 2002-2011 National Hospital Ambulatory Medical Care Survey. Logistic regression analyses examined the likelihood of opioid prescription among visits with specific mental disorder diagnoses (anxiety, attention, mood, psychotic, post-traumatic stress disorder (PTSD), opioid use, and non-opioid substance use), adjusted for covariates and weighted for the complex survey design. Secondary analyses stratified results by whether opioids were newly initiated or continued.

RESULTS

Opioids were prescribed at 16.8 % of visits. Mood, anxiety, and non-opioid substance use disorders were associated with higher likelihoods of opioid prescriptions, particularly for continued rather than first-time prescriptions. Psychotic disorders were strongly negatively associated with opioid prescriptions (adjusted odds ratio 0.44, 95 % CI 0.22-0.86). Diagnoses of PTSD and attention disorders were not associated with opioid prescribing.

CONCLUSIONS

Outpatient physicians are more likely to prescribe and refill opioids for adults with pain who present with mood, anxiety, and non-opioid substance use disorders, but not for those who present with PTSD or attention disorders. Patients with psychotic disorders and pain are markedly less likely to be prescribed opioids.

No evidence of associations between genetic liability for schizophrenia and development of cannabis use disorder

BACKGROUND

Cannabis use and cannabis use disorder (CUD) is increased in patients with schizophrenia. It is important to establish if this is explained by non-causal factors, such as shared genetic vulnerability. We aimed to investigate whether the polygenic risk scores (PRS) for schizophrenia and other psychiatric disorders would predict CUD in controls, patients with schizophrenia, and patients with other psychiatric disorders.

METHODS

We linked nationwide Danish registers and genetic information obtained from dried neonatal bloodspots in an observational analysis. We included people with schizophrenia, other psychiatric disorders, and controls. The exposures of interest were the PRS for schizophrenia, attention-deficit hyperactivity disorder (ADHD) autism spectrum disorder, and anorexia nervosa. The main outcome of interest was the diagnosis of CUD.

RESULTS

The study included 88 637 individuals. PRS for schizophrenia did not predict CUD in controls [hazard ratio (HR) = 1.16, 95% CI 0.95-1.43 per standard-deviation increase in PRS, or HR = 1.47, 95% CI 0.72-3.00 comparing highest v. remaining decile], but PRS for ADHD did (HR = 1.27, 95% CI 1.08-1.50 per standard-deviation increase, or HR = 2.02, 95% CI 1.27-3.22 for the highest decile of PRS). Among cases with schizophrenia, the PRS for schizophrenia was associated with CUD. While CUD was a strong predictor of schizophrenia (HR = 4.91, 95% CI 4.36-5.53), the inclusion of various PRS did not appreciably alter this association.

CONCLUSION

The PRS for schizophrenia was not associated with CUD in controls or patients with other psychiatric disorders than schizophrenia. This speaks against the hypothesis that shared genetic vulnerability would explain the association between cannabis and schizophrenia.

Co-occurrence across time and space of drug- and cannabinoid- exposure and adverse mental health outcomes in the National Survey of Drug Use and Health: combined geotemporospatial and causal inference analysis

BACKGROUND

Whilst many studies have linked increased drug and cannabis exposure to adverse mental health (MH) outcomes their effects on whole populations and geotemporospatial relationships are not well understood.

METHODS

Ecological cohort study of National Survey of Drug Use and Health (NSDUH) geographically-linked substate-shapefiles 2010-2012 and 2014-2016 supplemented by five-year US American Community Survey. Drugs: cigarettes, alcohol abuse, last-month cannabis use and last-year cocaine use. MH: any mental illness, major depressive illness, serious mental illness and suicidal thinking.

DATA ANALYSIS

two-stage, geotemporospatial, robust generalized linear regression and causal inference methods in R.

RESULTS

410,138 NSDUH respondents. Average response rate 76.7%. When drug and sociodemographic variables were combined in geospatial models significant terms including tobacco, alcohol, cannabis exposure and various ethnicities remained in final models for all four major mental health outcomes. Interactive terms including cannabis were related to any mental illness (β-estimate = 1.97 (95%C.I. 1.56-2.37), P <  2.2 × 10^- 16), major depressive episode (β-estimate = 2.03 (1.54-2.52), P = 3.6 × 10^- 16), serious mental illness (SMI, β-estimate = 2.04 (1.48-2.60), P = 1.0 × 10^- 12), suicidal ideation (β-estimate = 1.99 (1.52-2.47), P <  2.2 × 10^- 16) and in each case cannabis alone was significantly associated (from β-estimate = - 3.43 (- 4.46 - -2.42), P = 3.4 × 10^- 11) with adverse MH outcomes on complex interactive regression surfaces. Geospatial modelling showed a monotonic upward trajectory of SMI which doubled (3.62 to 7.06%) as cannabis use increased. Extrapolated to whole populations cannabis decriminalization (4.26%, (4.18, 4.34%)), Prevalence Ratio (PR) = 1.035(1.034-1.036), attributable fraction in the exposed (AFE) = 3.28%(3.18-3.37%), P < 10^- 300) and legalization (4.75% (4.65, 4.84%), PR = 1.155 (1.153-1.158), AFE = 12.91% (12.72-13.10%), P < 10^- 300) were associated with increased SMI vs. illegal status (4.26, (4.18-4.33%)).

CONCLUSIONS

Data show all four indices of mental ill-health track cannabis exposure across space and time and are robust to multivariable adjustment for ethnicity, socioeconomics and other drug use. MH deteriorated with cannabis legalization. Cannabis use-MH data are consistent with causal relationships in the forward direction and include dose-response and temporal-sequential relationships. Together with similar international reports and numerous mechanistic studies preventative action to reduce cannabis use is indicated.

Identification of de novo mutations in prenatal neurodevelopment-associated genes in schizophrenia in two Han Chinese patient-sibling family-based cohorts

Schizophrenia (SCZ) is a severe psychiatric disorder with a strong genetic component. High heritability of SCZ suggests a major role for transmitted genetic variants. Furthermore, SCZ is also associated with a marked reduction in fecundity, leading to the hypothesis that alleles with large effects on risk might often occur de novo. In this study, we conducted whole-genome sequencing for 23 families from two cohorts with unaffected siblings and parents. Two nonsense de novo mutations (DNMs) in GJC1 and HIST1H2AD were identified in SCZ patients. Ten genes (DPYSL2, NBPF1, SDK1, ZNF595, ZNF718, GCNT2, SNX9, AACS, KCNQ1, and MSI2) were found to carry more DNMs in SCZ patients than their unaffected siblings by burden test. Expression analyses indicated that these DNM implicated genes showed significantly higher expression in prefrontal cortex in prenatal stage. The DNM in the GJC1 gene is highly likely a loss function mutation (pLI = 0.94), leading to the dysregulation of ion channel in the glutamatergic excitatory neurons. Analysis of rare variants in independent exome sequencing dataset indicates that GJC1 has significantly more rare variants in SCZ patients than in unaffected controls. Data from genome-wide association studies suggested that common variants in the GJC1 gene may be associated with SCZ and SCZ-related traits. Genes co-expressed with GJC1 are involved in SCZ, SCZ-associated pathways, and drug targets. These evidences suggest that GJC1 may be a risk gene for SCZ and its function may be involved in prenatal and early neurodevelopment, a vulnerable period for developmental disorders such as SCZ.

Assessment of coexisting psychosis and substance misuse: complexities, challenges and causality

Substance misuse worsens the prognosis for people suffering psychosis and places them at risk of being denied appropriate mental health service interventions. To increase the chances of its success, the plan of management for patients with coexisting psychosis and substance misuse should be based on a valid formulation of their problems, which in turn is dependent on the clinician having (a) a thorough understanding of the bidirectional and changing ways that substance use and mental illness symptoms can interact, (b) an awareness of their own biased implicit assumptions about causality in explaining these interactions and (c) a framework for assessment and formulation. This article addresses these three areas with reference to the evidence base and to clinical experience in a way that guides mental health clinicians in the assessment of patients with coexisting psychosis and substance misuse.

Investigation of Schizophrenia with Human Induced Pluripotent Stem Cells

Schizophrenia is a chronic and severe neuropsychiatric condition manifested by cognitive, emotional, affective, perceptual, and behavioral abnormalities. Despite decades of research, the biological substrates driving the signs and symptoms of the disorder remain elusive, thus hampering progress in the development of treatments aimed at disease etiologies. The recent emergence of human induced pluripotent stem cell (hiPSC)-based models has provided the field with a highly innovative approach to generate, study, and manipulate living neural tissue derived from patients, making possible the exploration of fundamental roles of genes and early-life stressors in disease-relevant cell types. Here, we begin with a brief overview of the clinical, epidemiological, and genetic aspects of the condition, with a focus on schizophrenia as a neurodevelopmental disorder. We then highlight relevant technical advancements in hiPSC models and assess novel findings attained using hiPSC-based approaches and their implications for disease biology and treatment innovation. We close with a critical appraisal of the developments necessary for both further expanding knowledge of schizophrenia and the translation of new insights into therapeutic innovations.

Cannabis use and psychosis: a review of reviews

We conducted a systematic review of meta-analyses and systematic reviews to evaluate the impact of cannabis use on the onset and course of psychoses. Following a systematic literature search of five data bases (2005-2016) and consecutive structured evaluation, we were able to include 26 systematic reviews and meta-analyses. The methodological quality of the included publications were in the range of high and poor. The scientific literature indicates that psychotic illness arises more frequently in cannabis users compared to non-users, cannabis use is associated with a dose-dependent risk of developing psychotic illness, and cannabis users have an earlier onset of psychotic illness compared to non-users. Cannabis use was also associated with increased relapse rates, more hospitalizations and pronounced positive symptoms in psychotic patients. We make recommendations about the type of research that is required to better characterize the relationship between cannabis use and the development and outcomes of psychosis.

Ethics and ego dissolution: the case of psilocybin

Despite the fact that psychedelics were proscribed from medical research half a century ago, recent, early-phase trials on psychedelics have suggested that they bring novel benefits to patients in the treatment of several mental and substance use disorders. When beneficial, the psychedelic experience is characterized by features unlike those of other psychiatric and medical treatments. These include senses of losing self-importance, ineffable knowledge, feelings of unity and connection with others and encountering 'deep' reality or God. In addition to symptom relief, psychedelic experiences often lead to significant changes in a patient's personality and worldview. Focusing on the case of psilocybin, we argue that the peculiar features of psychedelics pose certain novel risks, which warrant an enhanced informed consent process-one that is more comprehensive than what may be typical for other psychiatric medications. We highlight key issues that should be focused on during the consent process and suggest discussion prompts for enhanced consent in psychedelic psychiatry. Finally, we respond to potential objections before concluding with a discussion of ethical considerations that will arise as psychedelics proceed from highly controlled research environments into mainstream clinical psychiatry.

[Addictive behaviors: Clinical facts]

Malgré les fréquentes comorbidités psychiatriques, le trouble de l’usage de substance doit être appréhendé comme une pathologie autonome par ses déterminants, sa sémiologie et ses modalités évolutives spontanées ou sous traitement. De multiples produits de synthèse sont désormais accessibles via internet : associé à la créativité des chimistes cela a participé à l’émergence de pratiques inédites allant du chemsex au purple drank. Les conduites addictives résultent d’un ensemble de facteurs individuels (vulnérabilités biologique et psychique) et contextuels (disponibilité et banalisation du toxique dans l’environnement). Les pathologies mentales autres sont des facteurs de vulnérabilité à la pathologie addictive, tout comme les conduites addictives peuvent révéler une pathologie émotionnelle ou psychotique. Le médecin se doit d’entendre l’impuissance du malade face au besoin irrépressible de consommer (craving) et proposer une thérapeutique qui peut être chimique (y compris traitement de substitution) et psychologique. Dans la majorité des cas, un accompagnement social s’impose pour corriger les effets désocialisants du trouble de l’usage de substances ou des comportements addictifs.

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.

The effects of acceptance and commitment therapy in psychosis treatment: A systematic review of randomized controlled trials

PURPOSE

To identify, evaluate, and synthesize existing randomized controlled trials (RCTs) that examine the effect of acceptance and commitment therapy (ACT) in the treatment of psychotic disorders and to integrate this knowledge and experience into the nursing literature.

DESIGN AND METHODS

This systematic review is based on the Joanna Briggs Institute and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

FINDINGS

This study was completed with 11 RCTs meeting the research criteria. It has been determined that the vast majority (82%) of the assessed studies were published after 2010. There is evidence that ACT is effective on depression, anxiety, and hallucinations seen in psychotic disorders.

PRACTICE IMPLICATIONS

ACT is seen as a reasonable approach to be used and tested by nurses and other clinicians because it provides an explanatory and pragmatic approach to psychotic disorders.

Schizophrenia is associated with increased risk of subsequent substance abuse diagnosis: A nation-wide population-based register study

AIMS

We aimed to investigate whether or not a diagnosis of schizophrenia increases the risk of a substance abuse diagnosis.

DESIGN

Prospective cohort study using a longitudinal study design.

SETTING AND PARTICIPANTS

Individuals born in Denmark from 1955 to 1999 and registered in the Danish registers between 1 January 1968 and 1 July 2013.

MEASUREMENTS

We investigated the associations between schizophrenia and ICD diagnoses of substance abuse, both established through various Danish registers. The Cox regression model was used and adjusted for calendar year, gender, urbanicity, co-abuse, other psychiatric diagnoses, parents' substance abuse and psychiatric history, parents' immigration and parents' socio-economic position. Individuals diagnosed with substance abuse less than a year after diagnosis of schizophrenia were classified as not diagnosed with schizophrenia.

FINDINGS

The cohort consisted of 3 133 968 individuals. During follow-up (103 212 328 person-years at risk), a total of 14 007 individuals developed schizophrenia, with 2885 subsequently diagnosed with substance abuse. A diagnosis of schizophrenia was positively associated with the risk of developing substance abuse [hazard ratio (HR) = 3.69, 95% confidence interval (CI) = 3.56-3.83]. Additionally, adjusting for a co-abuse markedly affected the associations, making schizophrenia primarily associated with an increased risk of abuse of cannabis, alcohol, stimulants and other substances (adjusted HR = 2.48, 95% CI = 2.34-2.64 for cannabis; HR = 1.94, 95% CI = 1.87-2.02 for alcohol; HR = 1.77, 95% CI = 1.61-1.95 for stimulants; HR = 1.36, 95% CI = 1.20-1.54 for other substances). The association was still significant 10-15 years subsequent a diagnosis of schizophrenia (HR = 2.50, 95% CI = 2.26-2.76).

CONCLUSIONS

In Denmark a diagnosis of schizophrenia is significantly associated with increased risk of subsequent diagnosis of substance abuse.

New alcohol-related genes suggest shared genetic mechanisms with neuropsychiatric disorders

Excessive alcohol consumption is one of the main causes of death and disability worldwide. Alcohol consumption is a heritable complex trait. Here we conducted a meta-analysis of genome-wide association studies of alcohol consumption (g d-1) from the UK Biobank, the Alcohol Genome-Wide Consortium and the Cohorts for Heart and Aging Research in Genomic Epidemiology Plus consortia, collecting data from 480,842 people of European descent to decipher the genetic architecture of alcohol intake. We identified 46 new common loci and investigated their potential functional importance using magnetic resonance imaging data and gene expression studies. We identify genetic pathways associated with alcohol consumption and suggest genetic mechanisms that are shared with neuropsychiatric disorders such as schizophrenia.

Methamphetamine use in an early psychosis service: a cross-sectional retrospective cohort study

OBJECTIVE

Methamphetamine-associated psychotic symptoms are common among regular users, and can overlap with the emergence of a primary psychotic disorder. In contrast to previous research, this retrospective observational study aims to describe the characteristics of young people experiencing early psychosis who use methamphetamine regularly. We also aimed to investigate associations between regular methamphetamine use and markers of psychosocial functioning, psychosis outcomes and substance use.

METHOD

This study involved 116 young people (19 using methamphetamine regularly) referred to the Camperdown Early Intervention in Psychosis Service from January 2015 to January 2016. Variables including demographic information, psychosocial functioning and psychosis outcomes were collected on referral to the service, updated throughout treatment and at discharge.

RESULTS

There were significant associations found between regular methamphetamine use and a criminal history (p<0.001), regular cannabis use (p=0.002) and regular nicotine use (p<0.001).

CONCLUSION

This study suggests that in early psychosis, regular methamphetamine use could signify a subgroup of young people who use multiple substances and may engage in criminal activity. Addressing substance use in early psychosis may be an important treatment target for this vulnerable group of young people.

Predictors of Transition to Psychosis in Individuals at Clinical High Risk

PURPOSE OF REVIEW

Current research is examining predictors of the transition to psychosis in youth who are at clinical high risk based on attenuated psychotic symptoms (APS). Determining predictors of the development of psychosis is important for an improved understanding of mechanisms as well as the development of preventative strategies. The purpose is to review the most recent literature identifying predictors of the transition to psychosis in those who are already assessed as being at risk.

RECENT FINDINGS

Multidomain models, in particular, integrated models of symptoms, social functioning, and cognition variables, achieve better predictive performance than individual factors. There are many methodological issues; however, several solutions have now been described in the literature. For youth who already have APS, predicting who may go on to later develop psychosis is possible. Several studies are underway in large consortiums that may overcome some of the methodological concerns and develop improved means of prediction.

Severe Mental Illness in Community Mental Health Care in Spain: Prevalence and Related Factors

The aims of this study were to determine the prevalence of severe mental illness (SMI) in patients in contact with mental health services and to determine the factors associated with SMI. A total of 260 patients who met diagnostic criteria for SMI were assessed using the Global Assessment of Functioning (GAF) scale and Health of the Nation Outcome Scales. The overall prevalence of SMI was 6.08 per thousand. According to the three different cutoff points with GAF, the prevalence of SMI ranged from 5.38 per thousand under the weak criterion (GAF < 70) to 1.01 per thousand under the strict criterion (GAF < 50). In the regression model, the dependent variable (presence of SMI) was defined using a GAF < 60, and the variables independently associated with the dependent variable were years of disease duration since diagnose, mental health service use, alcohol or other substance abuse, and depressive anxiety and other psychological symptoms.

Women who suffer from schizophrenia: Critical issues

Many brain diseases, including schizophrenia, affect men and women unequally - either more or less frequently, or at different times in the life cycle, or to varied degrees of severity. With updates from recent findings, this paper reviews the work of my research group over the last 40 years and underscores issues that remain critical to the optimal care of women with schizophrenia, issues that overlap with, but are not identical to, the cares and concerns of men with the same diagnosis. Clinicians need to be alert not only to the overarching needs of diagnostic groups, but also to the often unique needs of women and men.

Adolescent inhalant use and psychosis risk - a prospective longitudinal study

BACKGROUND

Cross-sectional studies have suggested inhalant use is associated with psychosis. This association was examined in a longitudinal study accounting for other substance use and potential confounders.

METHODS

We used a prospective sample (N = 6542) from the Northern Finland Birth Cohort 1986. Self-report questionnaires on substance use and psychotic experiences were completed when the cohort members were 15-16 years old. Inhalant use was categorized into four groups (never, once, 2-4 times, 5 times or more). Subsequent psychosis diagnoses (ICD-10) until age 30 years were obtained from national registers. Cox regression analysis was used to examine the association between adolescent inhalant use and risk of psychosis.

RESULTS

During the observation period 124 individuals were diagnosed with incident psychosis. Overall, there were 225 (3.4%) subjects with any inhalant use, 18 (8.0%) of whom were diagnosed with psychosis during the follow up. Of non-inhalant users (n = 6317) 106 (1.7%) were diagnosed with psychosis. Compared to non-users, those using inhalants had increased risk of incident psychosis with most frequent inhalant use associated with the greatest risk (unadjusted HR = 9.46; 3.86-23.20). After adjusting for baseline psychotic experiences, other substance use, comorbid mental disorder and parental substance abuse, the increased risk of psychosis persisted (HR = 3.06; 1.05-8.95). Furthermore, a dose-response effect between inhalant use and risk of psychosis was identified (OR = 2.34; 1.83-2.99).

CONCLUSIONS

Inhalant use in adolescence was independently associated with incident psychosis. The adverse health outcomes associated with adolescent inhalant use provide compelling reasons for implementation of policies to reduce the use of volatile substances in adolescents.

Sensorimotor gating deficits in "two-hit" models of schizophrenia risk factors

Genetic and environmental models of neuropsychiatric disease have grown exponentially over the last 20years. One measure that is often used to evaluate the translational relevance of these models to human neuropsychiatric disease is prepulse inhibition of startle (PPI), an operational measure of sensorimotor gating. Deficient PPI characterizes several neuropsychiatric disorders but has been most extensively studied in schizophrenia. It has become a useful tool in translational neuropharmacological and molecular genetics studies because it can be measured across species using almost the same experimental parameters. Although initial studies of PPI in rodents were pharmacological because of the robust predictive validity of PPI for antipsychotic efficacy, more recently, PPI has become standard common behavioral measures used in genetic and neurodevelopmental models of schizophrenia. Here we review "two hit" models of schizophrenia and discuss the utility of PPI as a tool in phenotyping these models of relevant risk factors. In the review, we consider approaches to rodent models of genetic and neurodevelopmental risk factors and selectively review "two hit" models of gene×environment and environment×environment interactions in which PPI has been measured.

Smokin' hot: adolescent smoking and the risk of psychosis

OBJECTIVE

Daily smoking has been associated with a greater risk of psychosis. However, we are still lacking studies to adjust for baseline psychotic experiences and other substance use. We examined associations between daily smoking and psychosis risk in a 15-year follow-up while accounting for these covariates in a prospective sample (N = 6081) from the Northern Finland Birth Cohort 1986.

METHODS

Self-report questionnaires on psychotic experiences (PROD-screen), tobacco smoking and other substance use were completed when the cohort members were 15-16 years old. Tobacco smoking was categorized into three groups (non-smokers, 1-9 cigarettes and ≥10 cigarettes/day). Psychosis diagnoses were obtained from national registers until the age of 30 years.

RESULTS

Subjects in heaviest smoking category were at increased risk of subsequent psychosis (unadjusted HR = 3.15; 95% CI 1.94-5.13). When adjusted for baseline psychotic experiences the association persisted (HR = 2.87; 1.76-4.68) and remained significant even after adjustments for multiple known risk factors such as cannabis use, frequent alcohol use, other illicit substance use, parental substance abuse, and psychosis. Furthermore, number of smoked cigarettes increased psychosis risk in a dose-response manner (adjusted OR = 1.05; 1.01-1.08).

CONCLUSION

Heavy tobacco smoking in adolescence was associated with a greater risk for psychosis even after adjustment for confounders.

Association of Substance Use Disorders With Conversion From Schizotypal Disorder to Schizophrenia

IMPORTANCE

Understanding the role of substance use disorders in conversion from schizotypal disorder to schizophrenia may provide physicians and psychiatrists with important tools for prevention or early detection of schizophrenia.

OBJECTIVE

To investigate whether substance use disorders, in particular cannabis use disorder, are associated with conversion to schizophrenia in individuals with schizotypal disorder.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study included a population-based sample of all individuals born in Denmark from January 1, 1981, through August 10, 2014, with an incident diagnosis of schizotypal disorder and without a previous diagnosis of schizophrenia. Follow-up was completed on August 10, 2014, and data were analyzed from March 10, 2017, through February 15, 2018.

EXPOSURES

Information on substance use disorders combined from 5 different registers.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards regression using time-varying information on substance use disorders and receipt of antipsychotics and adjusted for parental history of mental disorders, sex, birth year, and calendar year were used to estimate hazard ratios (HRs) and 95% CIs for conversion to schizophrenia.

RESULTS

A total of 2539 participants with incident schizotypal disorder were identified (1448 men [57.0%] and 1091 women [43.0%]; mean [SD] age, 20.9 [4.4] years). After 2 years, 16.3% (95% CI, 14.8%-17.8%) experienced conversion to schizophrenia. After 20 years, the conversion rate was 33.1% (95% CI, 29.3%-37.3%) overall and 58.2% (95% CI, 44.8%-72.2%) among those with cannabis use disorders. In fully adjusted models, any substance use disorder was associated with conversion to schizophrenia (HR, 1.34; 95% CI, 1.11-1.63). When data were stratified by substance, cannabis use disorders (HR, 1.30; 95% CI, 1.01-1.68), amphetamine use disorders (HR, 1.90; 95% CI, 1.14-3.17), and opioid use disorders (HR, 2.74; 95% CI, 1.38-5.45) were associated with conversion to schizophrenia. These associations were not explained by concurrent use of antipsychotics, functional level before incident schizotypal disorder, or parental history of mental disorders.

CONCLUSIONS AND RELEVANCE

Substance use disorders, in particular cannabis, amphetamines, and opioids, may be associated with conversion from schizotypal disorder to schizophrenia. However, conversion rates are high even in those without substance use disorders, indicating a need for universal and substance-targeted prevention in individuals with schizotypal disorder.