A systematic review and meta-analysis of synthetic cathinone use and psychosis.

RATIONALE: Synthetic cathinones (SC), commonly referred to as "bath salts", are stimulants resembling the natural alkaloid cathinone found in the khat plant. These substances have the potential to induce serious health risks such as hallucinations, delusions, paranoia and agitation which can lead to substance-induced psychotic disorders. Despite growing concerns, there is a limited understanding of the association between SC consumption and the devolvement of such psychopathologies. METHODS: We conducted a systematic review to investigate the frequency of substance-induced psychotic disorder (SIPD) and associated conditions in humans following synthetic cathinone consumption. We qualitatively and quantitatively analyzed SC exposure cases. RESULTS: A total of 32 studies were included, with a diverse range of demographics, synthetic cathinone types, and consumption patterns. The proportion of individuals developing psychotic symptoms was reported at 0.380 (Random-effects model, 95% CI 0.289 - 0.475). Additionally, the significant heterogeneity in diagnostic approaches limited our ability to provide a precise estimate of prevalence. CONCLUSIONS: Synthetic cathinone consumption is associated with the risk of developing psychotic symptoms as indicated by the prevalence of hallucinations and/or delusions. Due to the lack of information on classifying factors, particularly duration of symptoms, we are unable to conclude synthetic cathinone-induced psychosis. Further research is warranted to elucidate the underlying mechanism linking synthetic cathinone consumption and psychosis. This review underscores the urgency of addressing the growing health risks posed by synthetic cathinone use. Additionally, it highlights the necessity of proper quantification of psychotic symptoms through scales and reporting of classification criteria to accurately diagnose SIPD.

Methamphetamine use and psychotic symptoms: findings from a New Zealand longitudinal birth cohort.

BACKGROUND: This study examined the association between methamphetamine use and psychotic symptoms in a New Zealand general population birth cohort (n = 1265 at birth). METHODS: At age 18, 21, 25, 30, and 35, participants reported on their methamphetamine use and psychotic symptoms in the period since the previous interview. Generalized estimating equations modelled the association between methamphetamine use and psychotic symptoms (percentage reporting any symptom, and number of symptoms per participant). Confounding factors included childhood individual characteristics, family socioeconomic circumstances and family functioning. Long term effects of methamphetamine use on psychotic symptoms were assessed by comparing the incidence of psychotic symptoms at age 30-35 for those with and without a history of methamphetamine use prior to age 30. RESULTS: After adjusting for confounding factors and time-varying covariate factors including concurrent cannabis use, methamphetamine use was associated with a modest increase in psychosis risk over five waves of data (adjusted odds ratio (OR) 1.33, 95% confidence interval (CI) 1.03-1.72 for the percentage measure; and IRR 1.24, 95% CI 1.02-1.50 for the symptom count measure). The increased risk of psychotic symptoms was concentrated among participants who had used at least weekly at any point (adjusted OR 2.85, 95% CI 1.21-6.69). Use of methamphetamine less than weekly was not associated with increased psychosis risk. We found no evidence for a persistent vulnerability to psychosis in the absence of continuing methamphetamine use. CONCLUSION: Methamphetamine use is associated with increased risk of psychotic symptoms in the general population. Increased risk is chiefly confined to people who ever used regularly (at least weekly), and recently.

Annual incidence of substance-induced psychoses in Scandinavia from 2000 to 2016.

BACKGROUND: Substance-induced psychosis (SIP) is a serious condition and may predispose for schizophrenia. We know too little about SIP incidence over time and across countries, including substance-specific SIPs. We estimated annual incidence rate of SIP in Denmark, Norway, and Sweden according to substance, age, gender, and socioeconomic background. METHODS: Data were drawn from registries covering the whole adult population in the countries. Annual incidence rate per 100 000 persons of SIPs was estimated for Denmark and Sweden from 2000 to 2016 and for Norway from 2010 to 2015. RESULTS: The annual incidence rate of any SIP fluctuated between 9.3 and 14.1. The most commonly occurring SIPs were those induced by alcohol, cannabis, amphetamines, and multiple substances. There was a steady decrease in the incidence rate of alcohol-induced psychosis from the first to the last year of the observation period in Denmark (from 4.9 to 1.5) and Sweden (from 4.5 to 2.2). The incidence rate of cannabis-induced psychosis increased in all countries, from 2.6 to 5.6 in Denmark, from 0.8 to 2.7 in Sweden, and from 1.8 to 3.0 in Norway. Median age of any SIP decreased in Denmark (from 36 to 29 years) and Sweden (from 41 to 31 years). Incidence rates were higher in men and in individuals on disability pension, and increased more among those with high parental education. CONCLUSIONS: We found similar and stable incidence rates of any SIP in all Scandinavian countries through the observation period. The incidence of alcohol-induced psychosis decreased. The incidence of cannabis-induced psychosis increased.

Neuropsychiatric toxicity and cycloserine concentrations during treatment for multidrug-resistant tuberculosis.

BACKGROUND: Cycloserine, or its structural analogue terizidone, has been associated with neuropsychiatric toxicity (psychosis, depression, and neuropathy). Prospective clinical data on the incidence of and risk factors for neuropsychiatric toxicity in TB patients treated with cycloserine are limited. METHODS: A prospective evaluation of neuropsychiatric toxicity was performed using validated screening tools in patients with multidrug-resistant tuberculosis treated with terizidone. Cox proportional hazard modelling was performed to explore the effects of clinical variables and measures of cycloserine pharmacokinetics in plasma. RESULTS: A total 144 participants were recruited: 86 were male and 58 were female; their median age was 35.7 years and 91 (63%) were HIV-infected. Fifty-five (38%) participants developed at least one neuropsychiatric event (30 cases per 100 person-months): 50 (35%) neuropathy, 14 (10%) depression, and 11 (8%) psychosis. Neuropathy was independently associated with cycloserine clearance ((adjusted hazard ratio 0.34 (aHR), P = 0.03)) and high-dose pyridoxine (200 mg vs 150 mg daily, aHR: 2.79, P = 0.01). CONCLUSIONS: A high incidence of early neuropsychiatric toxicity was observed in this cohort of patients treated with terizidone. Cycloserine clearance and higher doses of pyridoxine are associated with incident or worsening peripheral neuropathy.

Direction of the relationship between methamphetamine use and positive psychotic symptoms in regular methamphetamine users: evidence from a prospective cohort study.

BACKGROUND: Methamphetamine has been consistently associated with positive psychotic symptoms, but little is known about whether the reverse also occurs. AIMS: This study determined whether the relationship between methamphetamine use and positive psychotic symptoms is bidirectional over 12 months. The impact of lifetime psychotic disorders and methamphetamine dependence on these relationships was also examined. METHOD: A total of 201 regular (at least monthly) primary methamphetamine users were recruited from free needle and syringe programmes in three Australian cities. Data on the frequency of methamphetamine and other drug use (from Timeline Followback inteviews) and the severity of positive psychotic symptoms (using the Brief Psychiatric Rating Scale) in the past 2 weeks were collected in 12 contiguous monthly face-to-face interviews (mean of 9.14/11 (s.d. = 3.16) follow-ups completed). Diagnoses were derived using the Psychiatric Research Interview for DSM-IV Substance and Mental Disorders. RESULTS: The mean age of participants was 31.71 years (s.d. = 8.19) and 39% (n = 77) were women. At baseline 55% (n = 110) were dependent on methamphetamine and 51% (n = 102) had a lifetime psychotic disorder. Cross-lagged dynamic panel models found a significant bidirectional relationship between psychotic symptoms and methamphetamine use (Comparative Fit Index (CFI) = 0.94, standardised root mean square residual (SRMR) = 0.05, root mean square error of approximation (RMSEA) = 0.05, 95% CI 0.04-0.06). The magnitude of the relationship in each direction was similar, and the presence of methamphetamine dependence or a lifetime psychotic disorder did not have an impact on results. CONCLUSIONS: A dynamic, bidirectional relationship between methamphetamine and psychotic symptoms of similar magnitude in each direction was found over 1 year. This suggests integrated treatments that target methamphetamine, psychotic symptoms and their interrelationship may be of most benefit.

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.

Differential effects of cannabis exposure during early versus later adolescence on the expression of psychosis in homeless and precariously housed adults.

Longitudinal studies of cannabis exposure during early adolescence in the general population frequently report an increased risk of subsequently developing psychotic symptoms or a psychotic illness. However, there is a dearth of knowledge about the effects of early cannabis exposure on psychosis in homeless and precariously housed adults, who represent a population afflicted with high rates of psychosis. The aim of the present study was to examine how early cannabis exposure (by age 15) compared to later first use (after age 15) affected the expression of adult psychosis in this population. Secondary measures of psychopathology, drug use, cognition and brain structure were also collected. 437 subjects were recruited from single room occupancy hotels in the urban setting of the Downtown Eastside of Vancouver, Canada. Psychiatric diagnoses were determined, and psychotic symptom severity was measured with the 5-factor PANSS. Participants completed a battery of neurocognitive tests, and brain structure was assessed using structural and diffusion tensor imaging MRI scans. Results indicated that early cannabis exposure was associated with an increased risk (OR = 1.09, p < .05) of developing substance induced psychosis, whereas later first use increased risk (OR = 2.19, p < .01) of developing schizophrenia or schizoaffective disorder. There was no group difference in neurocognitive function, although differences were observed in the lateral orbitofrontal cortex and white matter tract diffusivity. These findings indicate that early cannabis exposure in this population may increase the risk of developing drug associated psychoses, which could potentially be mediated in part through altered neurodevelopmental brain changes.

Risk of depression, suicide and psychosis with hydroxychloroquine treatment for rheumatoid arthritis: a multinational network cohort study.

OBJECTIVES: Concern has been raised in the rheumatology community regarding recent regulatory warnings that HCQ used in the coronavirus disease 2019 pandemic could cause acute psychiatric events. We aimed to study whether there is risk of incident depression, suicidal ideation or psychosis associated with HCQ as used for RA. METHODS: We performed a new-user cohort study using claims and electronic medical records from 10 sources and 3 countries (Germany, UK and USA). RA patients ≥18 years of age and initiating HCQ were compared with those initiating SSZ (active comparator) and followed up in the short (30 days) and long term (on treatment). Study outcomes included depression, suicide/suicidal ideation and hospitalization for psychosis. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate database-specific calibrated hazard ratios (HRs), with estimates pooled where I2 <40%. RESULTS: A total of 918 144 and 290 383 users of HCQ and SSZ, respectively, were included. No consistent risk of psychiatric events was observed with short-term HCQ (compared with SSZ) use, with meta-analytic HRs of 0.96 (95% CI 0.79, 1.16) for depression, 0.94 (95% CI 0.49, 1.77) for suicide/suicidal ideation and 1.03 (95% CI 0.66, 1.60) for psychosis. No consistent long-term risk was seen, with meta-analytic HRs of 0.94 (95% CI 0.71, 1.26) for depression, 0.77 (95% CI 0.56, 1.07) for suicide/suicidal ideation and 0.99 (95% CI 0.72, 1.35) for psychosis. CONCLUSION: HCQ as used to treat RA does not appear to increase the risk of depression, suicide/suicidal ideation or psychosis compared with SSZ. No effects were seen in the short or long term. Use at a higher dose or for different indications needs further investigation. TRIAL REGISTRATION: Registered with EU PAS (reference no. EUPAS34497; http://www.encepp.eu/encepp/viewResource.htm? id=34498). The full study protocol and analysis source code can be found at https://github.com/ohdsi-studies/Covid19EstimationHydroxychloroquine2.

Psychiatric Disorders and Hydroxychloroquine for Coronavirus Disease 2019 (COVID-19): A VigiBase Study.

INTRODUCTION: In the stressful context of the coronavirus disease 2019 (COVID-19) pandemic, some reports have raised concerns regarding psychiatric disorders with the use of hydroxychloroquine. In this study, we reviewed all psychiatric adverse effects with hydroxychloroquine in COVID-19 patients, as well as in other indications, reported in VigiBase, the World Health Organization's (WHO) global database of individual case safety reports. METHODS: First, we analyzed all psychiatric adverse effects, including suicide, of hydroxychloroquine in COVID-19 patients reported to 16 June 2020. We also performed disproportionality analysis to investigate the risk of reporting psychiatric disorders with hydroxychloroquine compared with remdesivir, tocilizumab, or lopinavir/ritonavir prescribed in COVID-19 patients. We used reporting odds ratios (RORs) and their 95% confidence intervals (CIs) to calculate disproportionality. Second, we sought to examine the psychiatric safety profile of hydroxychloroquine in other indications (before 2020). RESULTS: Among the 1754 reports with hydroxychloroquine in COVID-19 patients, we found 56 psychiatric adverse effects. Half of these adverse effects were serious, including four completed suicides, three cases of intentional self-injury, and 12 cases of psychotic disorders with hallucinations. Compared with remdesivir, tocilizumab, or lopinavir/ritonavir, the use of hydroxychloroquine was associated with an increased risk of reporting psychiatric disorders (ROR 6.27, 95% CI 2.74-14.35). Before 2020, suicide was the main cause of death among all adverse drug reactions reported with hydroxychloroquine, followed by cardiac adverse effects (cardiomyopathy) and respiratory failure. CONCLUSIONS: This pharmacovigilance analysis suggests that COVID-19 patients exposed to hydroxychloroquine experienced serious psychiatric disorders, and, among these patients, some committed suicide. Further real-world studies are needed to quantify the psychiatric risk associated with hydroxychloroquine during the COVID-19 pandemic.

[Risk of psychosis with treatment for ADHD]. / Kans op psychose bij behandeling van ADHD.

The study by Moran et al. on the risk of psychosis among adolescents in the US who are treated with a stimulant for ADHD is important. This is because ADHD is a common disorder (3-5%), because psychosis often emerges in adolescence, because ADHD and psychosis share increased comorbidity and because ADHD is treated with stimulant medication that may increase the risk of psychosis. This means there is a multifactorial relationship between ADHD and psychosis.The outcome of the study is that stimulants increase the risk of psychosis to a limited extent, i.e. 0.10% for methylphenidate and 0.21% for dexamphetamine. It is recommended to opt for methylphenidate in adolescents with ADHD. This is confirmed by a Swedish registry study that controlled for a history of psychosis and showed that methylphenidate did not increase the incidence of psychosis after one year, regardless of a history of psychosis.

Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study.

Cannabis is the illicit drug most commonly used worldwide, and its consumption can both induce psychiatric symptoms in otherwise healthy subjects and unmask a florid psychotic picture in patients with a prior psychotic risk. Previous studies suggest that chronic and long-term cannabis exposure may exert significant negative effects in brain areas enriched with cannabinoid receptors. However, whether brain alterations determined by cannabis dependency will lead to a clinically significant phenotype or to a psychotic outbreak at some point of an abuser's life remains unclear. The aim of this study was to investigate morphological brain differences between chronic cannabis users with cannabis-induced psychosis (CIP) and non-psychotic cannabis users (NPCU) without any psychiatric conditions and correlate brain deficits with selective socio-demographic, clinical and psychosocial variables. 3T magnetic resonance imaging (MRI) scans of 10 CIP patients and 12 NPCU were acquired. The type of drug, the frequency, and the duration, as well socio-demographic, clinical and psychosocial parameters of dependency were measured. CIP patients had extensive grey matter (GM) decreases in right superior frontal gyrus, right precentral, right superior temporal gyrus, insula bilaterally, right precuneus, right medial occipital gyrus, right fusiform gyrus, and left hippocampus in comparison to chronic cannabis users without psychosis. Finally, in CIP patients, the results showed a negative correlation between a domain of the Brief Psychiatric Rating Scale (BPRS), BPRS-Activity, and selective GM volumes. Overall, the results suggest that cannabis-induced psychosis is characterized by selective brain reductions that are not present in NPCU. Therefore, neuroimaging studies may provide a potential ground for identifying putative biomarkers associated with the risk of developing psychosis in cannabis users.

Association between amphetamine-related disorders and dementia-a nationwide cohort study in Taiwan.

OBJECTIVE: We have conducted a study to clarify the association between amphetamine-related disorders (ARD) and the risk of developing dementia. METHODS: This study used a retrospective cohort design by using Taiwan's National Health Research Institute Database. A random sample of 68,300 subjects between January 1, 2000, and December 31, 2015, was obtained, comprising of 17,075 patients with ARD, and 51,225 controls without ARD (1:3), matched for gender and age group. After adjusting for covariates, a Fine and Gray's survival analysis (competing with mortality) was used to compare the risk of dementia during a 15-year follow-up period. RESULTS: In the present study, 1,751 of 17,075 patients with ARD and 2,147 of 51,225 in the control group without ARD (883.10 vs 342.83 per 100,000 person-years) developed dementia. ARD cohort was more likely to develop dementia (hazard ratio = 4.936 [95% CI: 4.609-5.285, P < 0.001). After adjusting for gender, age groups, education, monthly insured premiums, urbanization level, geographic region, comorbidities, the hazard ratio for ARD patients was 5.034 (95% CI: 4.701-5.391, P < 0.001). ARD has been associated with overall dementia, Alzheimer dementia, vascular dementia, and other dementia. Both the amphetamine use disorder and amphetamine-induced psychotic disorders were associated with the risk of overall dementia, Alzheimer dementia, vascular dementia, and other dementia. INTERPRETATION: This study shows that patients with ARD, both the amphetamine use disorder and the amphetamine-induced psychotic disorder, may have a nearly fivefold risk of developing dementia, including Alzheimer dementia and other types of dementia.

Psychotic disorder and cannabis use: Canadian hospitalization trends, 2006-2015. / Troubles psychotiques et consommation de cannabis : évolution des hospitalisations au Canada, 2006-2015.

INTRODUCTION: Given the recent and impending changes to the legal status of nonmedical cannabis use in Canada, understanding the effects of cannabis use on the health care system is important for evaluating the impact of policy change. The aim of this study was to examine pre-legalization trends in hospitalizations for mental and behavioural disorders due to the use of cannabis, according to demographics factors and clinical conditions. METHODS: We assessed the total number of inpatient hospitalizations for psychiatric conditions with a primary diagnosis of a mental or behavioural disorder due to cannabis use (ICD-10-CA code F12) from the Hospital Mental Health Database for ten years spanning 2006 to 2015, inclusive. We included hospitalizations from all provinces and territories except Quebec. Rates (per 100 000 persons) and relative proportions of hospitalizations by clinical condition, age group, sex and year are reported. RESULTS: Between 2006 and 2015, the rate of cannabis-related hospitalizations in Canada doubled. Of special note, however, is that hospitalizations during this time period for those with the clinical condition code "mental and behavioural disorders due to use of cannabinoids, psychotic disorder" (F12.5) tripled, accounting for almost half (48%) of all cannabis-related hospitalizations in 2015. CONCLUSION: Further research is required to investigate the reasons for the increase in hospitalizations for cannabis-related psychotic disorder. The introduction of high-potency cannabinoid products and synthetic cannabinoids into the illicit market are considered as possible factors.

Association of Megestrol Use With the Development of New Psychiatric Diagnoses.

OBJECTIVE: To analyze the risk of megestrol, a glucocorticoid and progesterone receptor agonist used to enhance appetite, on the development of a new psychiatric diagnosis. DESIGN AND PARTICIPANTS: Deidentified data of megestrol (n = 706) and propensity score-matched comparison (age, gender, and body mass index) patients (n = 2,118) from January 1, 2001 to June 30, 2018 were obtained from the UT Southwestern patient database. Data were analyzed using a series of conditional binary logistic regressions controlling for comorbidities, pre-existing psychiatric disorders, and number of patient encounters. SETTING: A large academic medical center database of megestrol-treated patients and matched comparison patients was used. MEASUREMENTS AND RESULTS: The regression model showed that megestrol was significantly associated with developing a new psychiatric diagnosis (B = 1.28, Wald χ21 = 83.12, odds ratio [OR] = 3.60, p <0.001). In subgroup analyses, development of cognitive (B = 2.42, Wald χ21 = 16.09, OR = 11.30, p <0.001), mood (B = 1.31, Wald χ21 = 40.38, OR = 3.70, p <0.001), and anxiety (B = 1.72, Wald χ21 = 45.28, OR = 5.60, p <0.001) disorders were also associated with megestrol use. CONCLUSIONS: Patients taking megestrol were significantly more likely to develop a new psychiatric diagnosis than comparison patients. Highest risks were associated with the development of cognitive diagnoses. The findings suggest that megestrol, like other glucocorticoid agonists, is associated with an increased risk of developing a psychiatric disorder. This risk should be considered when determining the risk-to-benefit ratio of megestrol use in patients.

Infections as a Risk Factor for and Prognostic Factor After Substance-Induced Psychoses.

OBJECTIVE: Previous studies have suggested that infections increase the risk of schizophrenia. In this study, the authors aimed to investigate 1) whether infections increase the risk of substance-induced psychosis, and 2) whether infections increase the risk of converting from substance-induced psychosis to schizophrenia. METHODS: The study data were drawn from the combined nationwide Danish registers and included all people born in Denmark since 1981. The authors used Cox proportional hazards regression with infections as time-varying covariates, estimating hazard ratios and 95% confidence intervals. Infections were operationalized both as any infection and by the site of infection. RESULTS: The study included 2,256,779 individuals, for whom 3,618 cases of incident substance-induced psychosis were recorded. Any infection increased the risk of substance-induced psychosis (hazard ratio=1.30, 95% CI=1.22-1.39). For the first 2 years, the risk was doubled. Hepatitis was the infection most strongly associated with substance-induced psychosis (hazard ratio=3.42, 95% CI=2.47-4.74). Different types of infections were linked with different types of substance-induced psychosis. Most associations remained significant after controlling for potential confounders, such as substance use disorders. Only hepatitis predicted conversion to schizophrenia after substance-induced psychosis (hazard ratio=1.87, 95% CI=1.07- 3.26). CONCLUSIONS: The study results support the hypothesis of an immunological component to psychosis.

Methamphetamine Use and Antipsychotic-related Extrapyramidal Side-effects in Patients with Psychotic Disorders.

Objective: Extrapyramidal side-effects (EPSE) are frequent in patients treated with antipsychotics and comorbid substance use disorders (SUDs). Methamphetamine has been shown to act as a dopaminergic neurotoxin. We aimed to determine whether EPSE occur more often in patients with psychotic disorders and co-occurring methamphetamine (MA) use disorders, and we examined the relationship between MA use, antipsychotic type, dose and EPSE. Methods: This study was a secondary analysis of data from three separate primary studies. Across all studies, psychiatric and SUD diagnoses were determined using the SCID-I for DSM-IV. EPSE were determined using the Simpson-Angus Scale (SAS) for Parkinsonism, the Barnes Akathisia Rating scale (BARS), and the Abnormal Involuntary Movement Scale (AIMS) for tardive dyskinesia. Participants were classified as having any EPSE if they scored above the cutoff on any of the EPSE scales (SAS, BARS, AIMS). We analyzed data using multivariable logistic regression analysis. Results: The sample included 102 patients with non-affective or affective psychotic disorders. Of the total sample, 65.7% were male, 54.9% had schizophrenia spectrum disorders, 20.5% bipolar type I disorder with psychotic features, 11.7% schizoaffective disorder and 12.7% had substance-induced psychosis. A diagnosis of a methamphetamine use disorder (abuse or dependence) was present in 25.5% of participants. EPSE occurred in 38.2% of patients and were significantly associated with MA use in the unadjusted and adjusted analysis, ORadj = 4.01, 95% CI [1.07, 14.98], p = .039. Patients with MA dependence and MA use >3 years were significantly more likely to have EPSE. We found a significant interaction effect between MA use disorders and standardized antipsychotic dose on the occurrence of EPSE, ORadj = 1.01, 95% CI [1.00, 1.01], p = .042, with MA users having a disproportionally higher likelihood of having EPSE compared to MA non-users as antipsychotic dosage increased. There were no significant associations of EPSE with comorbid alcohol, cannabis, or methaqualone use disorders. Conclusions: Patients with a MA use disorder were significantly more likely to have EPSE with evidence for a dose-response effect. Clinicians should carefully titrate antipsychotic dosage from lower to higher doses to avoid EPSE in patients with MA use disorders.

Cannabis and Psychosis Through the Lens of DSM-5.

Evidence for an association between cannabis and psychosis has been documented in literature in many forms including experimental studies, epidemiological data, and case series. The association has implications for psychotic outcomes ranging from mild to severe and occurring over minutes to years. Due to the huge variety of exposures and outcome measures reported, creating a coherent account of all the available information is difficult. A useful way to conceptualize these wide-ranging results is to consider the association between cannabis and psychosis as it occurs within the context of widely used DSM-5 diagnoses. In the present review we examine cannabis/psychosis associations as they pertain to Cannabis Intoxication, Cannabis-Induced Psychotic Disorder, and Schizophrenia. This allows for an understanding of the cannabis and psychosis association along something approaching a continuum. Cannabis intoxication becomes Cannabis-Induced Psychotic Disorder once certain severity and duration criteria are met and Cannabis-Induced Psychotic Disorder is heavily associated with future schizophrenia diagnoses.