Factors affecting severity of positive and negative symptoms of psychosis in a polysubstance using population with psychostimulant dependence

Goofballing of Opioid and Methamphetamine: The Science Behind the Deadly Cocktail

Globally, millions of people suffer from various substance use disorders (SUD), including mono-and polydrug use of opioids and methamphetamine. Brain regions such as the cingulate cortex, infralimbic cortex, dorsal striatum, nucleus accumbens, basolateral and central amygdala have been shown to play important roles in addiction-related behavioral changes. Clinical and pre-clinical studies have characterized these brain regions and their corresponding neurochemical changes in numerous phases of drug dependence such as acute drug use, intoxication, craving, withdrawal, and relapse. At present, many studies have reported the individual effects of opioids and methamphetamine. However, little is known about their combined effects. Co-use of these drugs produces effects greater than either drug alone, where one decreases the side effects of the other, and the combination produces a prolonged intoxication period or a more desirable intoxication effect. An increasing number of studies have associated polydrug abuse with poorer treatment outcomes, drug-related deaths, and more severe psychopathologies. To date, the pharmacological treatment efficacy for polydrug abuse is vague, and still at the experimental stage. This present review discusses the human and animal behavioral, neuroanatomical, and neurochemical changes underlying both morphine and methamphetamine dependence separately, as well as its combination. This narrative review also delineates the recent advances in the pharmacotherapy of mono- and poly drug-use of opioids and methamphetamine at clinical and preclinical stages.

Negative symptoms in schizophrenia: correlation with clinical and genetic factors

Aim: Explore the possible association between clinical factors and genetic variants of the dopamine pathways and negative symptoms. Materials & methods: Negative symptoms were assessed in 206 patients with schizophrenia using the Arabic version of the self-evaluation of negative symptoms scale and the Positive and Negative Syndrome Scale. Genotyping for COMT, DRD2, MTHFR and OPRM1 genes was performed. Results: Multivariable analysis showed that higher self-evaluation of negative symptoms scale scores were significantly associated with higher age, higher chlorpromazine-equivalent daily dose for typical antipsychotics and in married patients. Higher negative Positive and Negative Syndrome Scale scores were significantly associated with women and having the CT genotype for MTHFR c.677C>T (β = 4.25; p = 0.008) compared with CC patients. Conclusion: Understanding both clinical/genetic factors could help improve the treatment of patients.

Duration of Neurocognitive Impairment With Medical Cannabis Use: A Scoping Review

While the recreational use of cannabis has well-established dose-dependent effects on neurocognitive and psychomotor functioning, there is little consensus on the degree and duration of impairment typically seen with medical marijuana use. Compared to recreational cannabis users, medical cannabis patients have distinct characteristics that may modify the presence and extent of impairment. The goal of this review was to determine the duration of acute neurocognitive impairment associated with medical cannabis use, and to identify differences between medical cannabis patients and recreational users. These findings are used to gain insight on how medical professionals can best advise medical cannabis patients with regards to automobile driving or safety-sensitive tasks at work. A systematic electronic search for English language randomized controlled trials (RCTs), clinical trials and systematic reviews (in order to capture any potentially missed RCTs) between 2000 and 2019 was conducted through Ovid MEDLINE and EMBASE electronic databases using MeSH terms. Articles were limited to medical cannabis patients using cannabis for chronic non-cancer pain or spasticity. After screening titles and abstracts, 37 relevant studies were subjected to full-text review. Overall, seven controlled trials met the inclusion/exclusion criteria and were included in the qualitative synthesis: six RCTs and one observational clinical trial. Neurocognitive testing varied significantly between all studies, including the specific tests administered and the timing of assessments post-cannabis consumption. In general, cognitive performance declined mostly in a THC dose-dependent manner, with steady resolution of impairment in the hours following THC administration. Doses of THC were lower than those typically reported in recreational cannabis studies. In all the studies, there was no difference between any of the THC groups and placebo on any neurocognitive measure after 4 h of recovery. Variability in the dose-dependent relationship raises the consideration that there are other important factors contributing to the duration of neurocognitive impairment besides the dose of THC ingested. These modifiable and non-modifiable factors are individually discussed.

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.

Factors associated with methamphetamine dependency among men who have sex with men engaging in chemsex: Findings from the COMeT study in Taiwan

BACKGROUND

Sexualized drug use or "chemsex" in Taiwan commonly incorporates the use of methamphetamine. Our study aimed to assess the extent of severity of dependence of methamphetamine among MSM in Taiwan as well as motivations for engagement in chemsex.

METHODS

Direct messages were sent to users of a large MSM social networking application in Taiwan between November 2018 and January 2019. MSM who had at least one experience of using drugs during sex in the preceding 12 months were invited to complete an online survey that assessed their sexual behavior, substance use and motivations for engaging in chemsex. The Severity of Dependence Scale was used to assess methamphetamine dependency. Multivariable logistic regression was used to determine the factors associated with methamphetamine dependency.

RESULTS

From a total of 1906 responses, 517 had used methamphetamine in their lifetime and were included in the analysis. The majority (87.2%) used more than one substance when engaging in chemsex in the past six months, while a quarter reported injection of methamphetamine within the last six months. The most commonly reported motivations for participants to engage in chemsex were to have fun, for relaxation, and to increase the intensity of the sexual experience. Nearly half (46.0%) exhibited signs of methamphetamine dependency. Lower monthly income, injection of methamphetamine, ever feeling lonely in the past 3 months and concerns about their substance use expressed by others were significantly associated with methamphetamine dependency.

CONCLUSION

A high proportion of MSM population who engaged in chemsex were at risk of developing methamphetamine dependency. While motivations for engaging in chemsex were diverse and suggest potential for enhanced sexual experience for some, community health organization for gay men's health and healthcare providers should be vigilant at identifying the risk of methamphetamine dependency and provide in-time, brief intervention or referrals when needed.

Network analysis of psychotic manifestations among cocaine users

Psychotic experiences can be described along a continuum ranging from no psychotic experience at all, to clinical psychotic disorder. Any individual in the general population may encounter psychotic experiences under certain circumstances. Transient Cocaine Induced Psychotic Symptoms (TCIPS) are a well described model of such circumstances. Therefore, our aim was to use a network analysis to get a better knowledge on the architecture of previously described risk factors and how they contributed to two different measures of psychosis (psychosis proneness and transient cocaine induced psychotic symptoms) This study is a secondary analysis conducted among 180 cocaine users in addiction care centers in Paris and Paris suburb, who were evaluated with the PDI (Peters Delusion Inventory) and the SAPS-CIP (Scale for the Assessment of Psychotic Symptoms - Cocaine Induced Psychosis). Schizophrenia diagnosis was extracted from medical record. Relevant variables significantly associated with SAPS-CIP total score or PDI at the first step were included in a network analysis to better figurate their respective associations. The network centrality measures showed that the product preferentially used (crack vs cocaine) was related to TCIPS, psychosis proneness and, to a lesser extent, schizophrenia. Secondly, in this model TCIPS is a mediator between intensive cocaine use and psychosis proneness. Thirdly, this study refines the previous knowledge on heavy cannabis use being a risk factor for TCIPS. The observed link is not direct but mediated by psychosis proneness.

Associations of substance use, psychosis, and mortality among people living in precarious housing or homelessness: A longitudinal, community-based study in Vancouver, Canada

BACKGROUND

The "trimorbidity" of substance use disorder and mental and physical illness is associated with living in precarious housing or homelessness. The extent to which substance use increases risk of psychosis and both contribute to mortality needs investigation in longitudinal studies.

METHODS AND FINDINGS

A community-based sample of 437 adults (330 men, mean [SD] age 40.6 [11.2] years) living in Vancouver, Canada, completed baseline assessments between November 2008 and October 2015. Follow-up was monthly for a median 6.3 years (interquartile range 3.1-8.6). Use of tobacco, alcohol, cannabis, cocaine, methamphetamine, and opioids was assessed by interview and urine drug screen; severity of psychosis was also assessed. Mortality (up to November 15, 2018) was assessed from coroner's reports and hospital records. Using data from monthly visits (mean 9.8, SD 3.6) over the first year after study entry, mixed-effects logistic regression analysis examined relationships between risk factors and psychotic features. A past history of psychotic disorder was common (60.9%). Nonprescribed substance use included tobacco (89.0%), alcohol (77.5%), cocaine (73.2%), cannabis (72.8%), opioids (51.0%), and methamphetamine (46.5%). During the same year, 79.3% of participants reported psychotic features at least once. Greater risk was associated with number of days using methamphetamine (adjusted odds ratio [aOR] 1.14, 95% confidence interval [CI] 1.05-1.24, p = 0.001), alcohol (aOR 1.09, 95% CI 1.01-1.18, p = 0.04), and cannabis (aOR 1.08, 95% CI 1.02-1.14, p = 0.008), adjusted for demographic factors and history of past psychotic disorder. Greater exposure to concurrent month trauma was associated with increased odds of psychosis (adjusted model aOR 1.54, 95% CI 1.19-2.00, p = 0.001). There was no evidence for interactions or reverse associations between psychotic features and time-varying risk factors. During 2,481 total person years of observation, 79 participants died (18.1%). Causes of death were physical illness (40.5%), accidental overdose (35.4%), trauma (5.1%), suicide (1.3%), and unknown (17.7%). A multivariable Cox proportional hazard model indicated baseline alcohol dependence (adjusted hazard ratio [aHR] 1.83, 95% CI 1.09-3.07, p = 0.02), and evidence of hepatic fibrosis (aHR 1.81, 95% CI 1.08-3.03, p = 0.02) were risk factors for mortality. Among those under age 55 years, a history of a psychotic disorder was a risk factor for mortality (aHR 2.38, 95% CI 1.03-5.51, p = 0.04, adjusted for alcohol dependence at baseline, human immunodeficiency virus [HIV], and hepatic fibrosis). The primary study limitation concerns generalizability: conclusions from a community-based, diagnostically heterogeneous sample may not apply to specific diagnostic groups in a clinical setting. Because one-third of participants grew up in foster care or were adopted, useful family history information was not obtainable.

CONCLUSIONS

In this study, we found methamphetamine, alcohol, and cannabis use were associated with higher risk for psychotic features, as were a past history of psychotic disorder, and experiencing traumatic events. We found that alcohol dependence, hepatic fibrosis, and, only among participants <55 years of age, history of a psychotic disorder were associated with greater risk for mortality. Modifiable risk factors in people living in precarious housing or homelessness can be a focus for interventions.

A comparison of regional brain volumes and white matter connectivity in subjects with stimulant induced psychosis versus schizophrenia

RATIONALE

Schizophrenia and stimulant-induced psychosis (SIP) represent two different forms of psychotic disorder, with different etiologies. While many of the symptoms of psychosis are common to both disorders, there have been few direct comparisons between these conditions, especially when controlling for stimulant use in individuals with schizophrenia.

OBJECTIVES

We directly compared both psychotic disorders with a comprehensive battery of clinical, neurocognitive and neuroanatomical measures. This included one group with SIP (and concurrent stimulant dependence) and two groups with schizophrenia (either with or without concurrent stimulant dependence).

METHODS

Ninety-six participants were recruited from a marginalized urban population, which included 39 with SIP (and concurrent stimulant dependence), 18 with schizophrenia (without stimulant dependence), and 39 with schizophrenia (with concurrent stimulant dependence). All subjects had extensive clinical and neurocognitive evaluations, complemented with structural MRI including diffusion tensor imaging (DTI) sequences to determine regional brain volumes and white matter connectivity.

RESULTS

Both positive and negative symptoms were greater in the SZ-dependent group than the other two. Neurocognitive function was broadly similar. The structural brain imaging revealed lateralized changes to the left parietal/temporal lobe, in which regional volumes were smaller in the SZ-dependent than the SZ-non-dependent group. DTI analysis indicated extensive decreases in fractional anisotropy, with parallel increases in radial diffusivity, in the SIP group compared to the SZ-dependent group.

CONCLUSIONS

These findings reveal both similarities and differences between SIP and schizophrenia. Furthermore, schizophrenia with concurrent stimulant dependence may be associated with a different clinical and neuroanatomical profile as compared to schizophrenia alone.

Characterization of mental health in cannabis dispensary users, using structured clinical interviews and standardized assessment instruments

BACKGROUND

Cannabis is commonly used for its medical properties. In particular, cannabis is purported to have beneficial effects on a wide range of neuropsychiatric conditions. Studies assessing mental health in cannabis dispensary users typically evaluate symptoms using self-report check lists, which provide limited information about symptom severity, and whether subjects meet criteria for a psychiatric diagnosis. There is, therefore, a need for studies which assess mental health in dispensary users with standardized and well validated scientific instruments, such as those used in clinical drug trials.

METHODS

One hundred medical cannabis users were recruited from a community dispensary. All subjects completed a structured clinical interview with the Mini-International Neuropsychiatric Interview (MINI). Subjects also completed the Perceived Stress Scale-10, PROMIS Fatigue Scale, PROMIS Sleep Disturbance Scale, Beck Depression Inventory, the Patient Health Questionnaire-15 and the Brief Pain Inventory. Details about cannabis use were also recorded.

RESULTS

Lifetime prevalence of mental illness in this cohort was high, and a large proportion of subjects endorsed psychological symptoms. The proportion of subjects who met criteria for classification of a current psychiatric disorder was low for mood disorders, but high for anxiety disorders and substance abuse/dependence. Cannabis use differed between the main psychiatric conditions.

CONCLUSIONS

The present results indicate that rates of mental illness may be high in medical cannabis dispensary users. Use of structured clinical assessments combined with standardized symptom severity questionnaires provide a feasible way to provide a more rigorous and detailed evaluation of conditions and symptoms in this population.

Is there a discrete negative symptom syndrome in people who use methamphetamine?

BACKGROUND

Positive psychotic symptoms have consistently been associated with methamphetamine use but the presence of a negative symptom cluster remains unclear. We used exploratory factor analysis to examine whether a discrete negative syndrome could be delineated among methamphetamine users, and to examine the clinical correlates of this syndrome.

METHOD

Participants (N = 154) were people who used methamphetamine at least monthly and did not meet DSM-IV diagnostic criteria for lifetime schizophrenia. Scores on the Brief Psychiatric Rating Scale for the past month were subject to exploratory factor analysis. Latent class analysis was applied to resultant factor scores to determine whether negative and positive factors were experienced by the same participants. Past-month substance use measures were days of use for each drug type and methamphetamine dependence assessed using the Severity of Dependence Scale.

RESULTS

We articulated a three-factor model including 'positive/activation symptoms' (e.g. suspiciousness, hallucinations, conceptual disorganisation, tension), 'affective symptoms' (e.g. depression, anxiety) and 'negative symptoms' (e.g. blunted affect, motor retardation). Positive-activation and affective symptoms (but not negative symptoms) were positively correlated with past month days of methamphetamine use (r = 0.16; r = 0.25) and severity of dependence (r = 0.24; r = 0.41). Negative symptoms were correlated with heroin (r = 0.24) and benzodiazepine use (r = 0.21). Latent class analysis revealed a three-class model comprising a positive-symptom class (44%, high positive-activation, low negative symptoms), a negative-symptom class (31%, low positive-activation, high negative symptoms), and a low-symptom class (38%, low on all factors).

CONCLUSIONS

A negative symptom syndrome exists among people who use methamphetamine, but this appears related to polysubstance use rather than forming a part of the psychotic syndrome associated with methamphetamine use. Overlooking the role of polysubstance use on negative symptoms may conflate the profiles of methamphetamine-associated psychosis and schizophrenia.

A Review of Risk Factors for Methamphetamine-Related Psychiatric Symptoms

The illegal use of methamphetamine (MA) is a growing public health concern globally and results in a series of negative effects. The prominent detrimental effect of MA use is MA-related psychiatric symptoms (MAP) and is observed at a much higher incidence compared to the general population. MAP often includes multiple dimensions of cognitive impairment and induces adverse consequences such as, violence and suicide. However, the assessment methods for MAP are not standardized. Hence, it is necessary to investigate factors that affect the progression of psychiatric symptoms in individuals who use MA. A review of published studies was performed by searching the following databases: PubMed, EMBASE, and PsycINFO from inception to 31 May, 2018. The search strategy included methamphetamine, dependence, psychiatric symptoms, and risk factor terms. We reviewed the different features of MAP and the various types of assessment instruments and summarized MAP risk factors from MA use-related factors, socio-demographic characteristics, life events, and genetic factors. We found that MAP was consistently and causally associated with MA use, particularly as it relates to the frequency and amount of MA use. Other MAP-related risk factors like life events and genetics were relatively inconsistent in their association with MAP. Hence, causal and longitudinal studies that focus on multilateral comparisons are required. This review provides high quality evidence for MAP risk factors and would be helpful for developing early prevention and treatment strategies for MAP.

The Hotel Study-Clinical and Health Service Effectiveness in a Cohort of Homeless or Marginally Housed Persons

OBJECTIVE

The Hotel Study was initiated in Vancouver's Downtown East Side (DTES) neighborhood to investigate multimorbidity in homeless or marginally housed people. We evaluated the clinical effectiveness of existing, illness-specific treatment strategies and assessed the effectiveness of health care delivery for multimorbid illnesses.

METHOD

For context, we mapped the housing locations of patients presenting for 552,062 visits to the catchment hospital emergency department (2005-2013). Aggregate data on 22,519 apprehensions of mentally ill people were provided by the Vancouver Police Department (2009-2015). The primary strategy was a longitudinal cohort study of 375 people living in the DTES (2008-2015). We analysed mortality and evaluated the clinical and health service delivery effectiveness for infection with human immunodeficiency virus or hepatitis C virus, opioid dependence, and psychosis.

RESULTS

Mapping confirmed the association between poverty and greater number of emergency visits related to substance use and mental illness. The annual change in police apprehensions did not differ between the DTES and other policing districts. During 1581 person-years of cohort observation, the standardized mortality ratio was 8.43 (95% confidence interval, 6.19 to 11.50). Physician visits were common (84.3% of participants over 6 months). Clinical treatment effectiveness was highest for HIV/AIDS, intermediate for opioid dependence, and lowest for psychosis. Health service delivery mechanisms provided examples of poor access, poor treatment adherence, and little effect on multimorbid illnesses.

CONCLUSIONS

Clinical effectiveness was variable, and illness-specific service delivery appeared to have little effect on multimorbidity. New models of care may need to be implemented.

A comparison of psychotic symptoms in subjects with methamphetamine versus cocaine dependence

RATIONALE

The psychostimulant drugs cocaine and methamphetamine are potent indirect dopamine receptor agonists which act through similar but not identical mechanisms. Studies in humans have observed that a large proportion of those who chronically use these drugs experience psychotic symptoms. However, direct comparisons of psychotic symptom severity between cocaine and methamphetamine users are lacking.

OBJECTIVES

The goal of the present study was to directly compare severity of psychotic symptoms between cocaine- and methamphetamine-dependent individuals. Additionally, we sought to determine how concurrent cocaine + methamphetamine dependence would influence psychotic symptoms.

METHODS

We recruited 153 polysubstance-using subjects meeting DSM-IV-TR criteria for cocaine dependence, 38 with methamphetamine dependence, and 32 with cocaine + methamphetamine dependence. Psychotic symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS) and analyzed using a five-factor model. All participants were also assessed for physical and mental illnesses as well as recent substance use. Most subjects completed a comprehensive neurocognitive battery.

RESULTS

While all three groups exhibited high total PANSS scores, the positive symptom subscale was significantly higher in the methamphetamine-dependent (17.03 ± 6.3) than the cocaine-dependent group (13.51 ± 4.12) and non-significantly higher (p = 0.08) than the cocaine + methamphetamine group (14.44 ± 5.50). Groups also differed on demographic variables, viral infection, and other indices of substance use, which were unlikely to account for the difference in positive symptoms. There were only modest differences between groups in neurocognitive function.

CONCLUSIONS

Methamphetamine dependence was associated with more severe positive symptoms of psychosis than cocaine dependence. Concurrent cocaine + methamphetamine dependence did not increase psychosis severity.

Experiences of Health Professionals Caring for People Presenting to the Emergency Department After Taking Crystal Methamphetamine ("ICE")

Globally, addiction to "ICE" (crystal methamphetamine) is increasing and presents emergency health care services personnel with a number of challenges. This paper reports the first of two major themes arising from a qualitative study investigating health professionals' experiences' managing people presenting to the Emergency Department (ED) after taking "ICE." The theme "Caring for people who use 'ICE' when presenting to EDs" comprises five subthemes. These are: (a) expecting the unexpected: "they're just off their heads"; (b) complexity of care: "underlying trauma and emotional dysregulation";