Cognitive functioning associated with stimulant use in patients with non-affective psychosis, their unaffected siblings and healthy controls

Assessing the validity of the Wechsler Adult Intelligence Scale (WAIS-IV) in predicting completion in a long-term residential rehabilitation for substance use problems

BACKGROUND

We aimed to examine the predictive validity of the Weschler Adult Intelligence Scale (WAIS-IV) in predicting treatment completion, over and above educational status.

METHODS

One hundred and ninety-six (N = 196) individuals from the Odyssey House Residential Rehabilitation Program, NSW, Australia between 2010 and 2016 were administered a structured interview including substance use disorders and the Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI) domains of the WAIS-IV.

RESULTS

There were significant differences between our clinical sample and the population norm with respect to the proportion below the mean for PSI (z = 12.27, p < .001), VCI (z = 2.33, p < .02) but not for WMI (z = 1.67, p < .10) or PRI (z = -1.76, p < .08). The WAIS-IV subscales did not significantly predict treatment completion (p's > .16) over and above educational status (p < .01).

CONCLUSIONS

Our findings suggest that in clients in drug and alcohol rehabilitation settings a combination of skills may be impacted including Verbal Comprehension and Processing Speed. Moreover, our findings also suggest that WAIS-IV subscales do not predict treatment completion in a drug and alcohol residential setting, over and above a brief assessment of educational status.

Cognitive state, substance use patterns and outcome after discharge from Kfar Izun, a unique rehabilitation facility

We studied cognitive performance following discharge from a novel rehabilitation facility, treating individuals with psychosis that developed during trips abroad following mandatory military service. Montreal Cognitive Assessment (MoCA), phonetic and semantic fluency, State-Trait Anxiety, and self-Efficiency were administered before discharge, and 3 and 6 months after discharge. Of the 43 participants (30.2% females), 23(54.8%) had cognitive impairment (MoCA <27), and 15(35.7%) had poor phonetic fluency. Anxiety trait and state were high and inversely correlated with self-efficacy (R=-0.48, p = 0.001) and phonetic fluency (R=-0.43, p = 0.004) and was higher among those who experienced physical exposure, females, and those who served in non-combat army units. Six months after discharge, of 32 participants, 28 were working/studying with a 58.1% reduction in smoking and alcohol consumption, and 16 participants stopped substance use. Phonetic fluency improved among the high anxiety state group with no change among the others. High anxiety levels lowered among those who were still using drugs after six months. The anxiety level lowered and 87.1% of the participants were conducting a productive lifestyle at 6 months after discharge, but half still abused cannabis. Bigger sample and longer follow up would be needed to learn more about the impact of rehabilitation.

Parcellating cognitive heterogeneity in early psychosis-spectrum illnesses: A cluster analysis

Cognitive impairment is argued to represent a core feature of psychosis-spectrum illnesses. However, within-diagnosis heterogeneity is common, and risk factors for poor cognition remain to be examined after statistically accounting for heterogeneity. Accordingly, we used a data-driven technique (cluster analysis) to empirically-derive cognitive clusters across diagnoses and examined whether concurrent substance use or a history of a neurodevelopmental/behavioral disorder differed between clusters. Data from 135 young help-seekers (aged 12-30 years) with a psychosis-spectrum illness were retrospectively analyzed. Ward's hierarchical cluster analysis classified three cognitive clusters characterized by: (1) normal-range; (2) mixed; and (3) grossly-impaired performance. Despite mostly comparable clinical and demographic measures, cluster 1 had superior socio-occupational functioning and the highest estimated premorbid IQ, followed sequentially by clusters 2 and 3. Proportions of cannabis and amphetamine users did not differ significantly across clusters, nor did rates of patients with a neurodevelopmental/behavioral disorder history. Cluster 3 was however comprised of fewer 'risky' drinkers, possibly reflecting reduced opportunity for social drinking associated with cognitive impairment. Estimated premorbid IQ predicted cluster membership (2 vs. 1 & 3 vs. 1), as did clinician-rated socio-occupational functioning and 'not being enrolled in school or tertiary education' (3 vs. 1). Our results suggest that concurrent substance use and history of a neurodevelopmental/behavioral disorder do not adequately explain cluster-level cognitive variance in this sample. Future work should integrate neurobiological measures associated with cognition (e.g. white matter integrity) to discern whether clusters reflect neurobiological subtypes better representative of pathophysiology than present symptom-based classifications.

Therapeutic potential of medicinal marijuana: an educational primer for health care professionals

With the proposed Canadian July 2018 legalization of marijuana through the Cannabis Act, a thorough critical analysis of the current trials on the efficacy of medicinal marijuana (MM) as a treatment option is necessary. This review is particularly important for primary care physicians whose patients may be interested in using MM as an alternative therapy. In response to increased interest in MM, Health Canada released a document in 2013 for general practitioners (GPs) as an educational tool on the efficacy of MM in treating some chronic and acute conditions. Although additional studies have filled in some of the gaps since the release of the Health Canada document, conflicting and inconclusive results continue to pose a challenge for physicians. This review aims to supplement the Health Canada document by providing physicians with a critical yet concise update on the recent advancements made regarding the efficacy of MM as a potential therapeutic option. An update to the literature of 2013 is important given the upcoming changes in legislation on the use of marijuana. Also, we briefly highlight the current recommendations provided by Canadian medical colleges on the parameters that need to be considered prior to authorizing MM use, routes of administration as well as a general overview of the endocannabinoid system as it pertains to cannabis. Lastly, we outline the appropriate medical conditions for which the authorization of MM may present as a practical alternative option in improving patient outcomes as well as individual considerations of which GPs should be mindful. The purpose of this paper is to offer physicians an educational tool that provides a necessary, evidence-based analysis of the therapeutic potential of MM and to ensure physicians are making decisions on the therapeutic use of MM in good faith.

Psychosis induced by amphetamines

PURPOSE OF REVIEW

The study reviews publications on the use of methamphetamine and amphetamine in relation to psychotic symptoms, substance-induced psychosis, and primary psychosis published between July 2014 and December 2015. The databases MEDLINE, Embase, and PsycINFO were searched using the terms 'amphetamine psychosis' and 'methamphetamine psychosis' for the time period 1 July 2014 to 31 December 2015.

RECENT FINDINGS

There were 37 studies published on the subject during this time period. Risk factors for psychotic symptoms, substance-induced psychosis, and primary psychosis included patterns of drug use, but results also pointed to the importance of nondrug-related vulnerability. Cognitive impairment is associated with both amphetamine use and psychosis, and the impairment among those with amphetamine-induced psychosis resembles that of schizophrenia. At the neuronal level, GABAergic mechanisms may offer some understanding about the association between stimulant use and psychosis. Several different types of antipsychotic medication are effective for treating agitation and psychosis, but drugs with high DRD2 blockade should be used with caution. Some novel treatments are described, but are not sufficiently repeated to be recommended.

SUMMARY

During the past 18 months, studies have been published that cover risk factors, neuronal mechanisms, and treatment. These recent results do not differ from previous understandings, but the role of cognition and GABAergic dysfunction should be further investigated, and knowledge about resilience factors is still scarce. Also, a clearer evidence base for medical treatment of psychosis with concurrent amphetamine use is warranted. VIDEO ABSTRACT.

Cannabis use is associated with 3years earlier onset of schizophrenia spectrum disorder in a naturalistic, multi-site sample (N=1119)

BACKGROUND

Patients with schizophrenia spectrum disorders and substance use may have an earlier onset of illness compared to those without substance use. Most previous studies have, however, too small samples to control for confounding variables and the effect of specific types of substances. The present study aimed to examine the relationship between substance use and age at onset, in addition to the influence of possible confounders and specific substances, in a large and heterogeneous multisite sample of patients with schizophrenia spectrum disorders.

METHODS

The patients (N=1119) were recruited from catchment areas in Oslo, Stavanger and Bergen, Norway, diagnosed according to DSM-IV and screened for substance use history. Linear regression analysis was used to examine the relationship between substance use and age at onset of illness.

RESULTS

Patients with substance use (n=627) had about 3years earlier age at onset (23.0years; SD 7.1) than the abstinent group (n=492; 25.9years; SD 9.7). Only cannabis use was statistically significantly related to earlier age at onset. Gender or family history of psychosis did not influence the results.

CONCLUSION

Cannabis use is associated with 3years earlier onset of psychosis.

Evaluating the relationship between cannabis use and IQ in youth and young adults at clinical high risk of psychosis

Among people with psychosis, those with a history of cannabis use show better cognitive performance than those who are cannabis naïve. It is unknown whether this pattern is present in youth at clinical high risk (CHR) of psychosis. We evaluated relationships between IQ and cannabis use while controlling for use of other substances known to impact cognition in 678 CHR and 263 healthy control (HC) participants. IQ was estimated using the Vocabulary and Block Design subtests of the Wechsler Abbreviated Scale of Intelligence. Drug and alcohol use severity and frequency were assessed with the Alcohol and Drug Use Scale, and we inquired participants' age at first use. CHR were further separated into early and late age at onset of cannabis use sub-groups, and low-, moderate- and high-frequency sub-groups. No significant differences in IQ emerged between CHR or HC cannabis users vs. non-users, or between use frequency groups. CHR late-onset users showed significantly higher IQ than CHR early-onset users. Age at onset of cannabis use was significantly and positively correlated with IQ in CHR only. Results suggest that age at onset of cannabis may be a more important factor for IQ than use current use or use frequency in CHR.

Sources of nonmedically used prescription stimulants: differences in onset, recency and severity of misuse in a population-based study

AIM

Epidemiological data indicate that nonmedical use of prescription stimulants has increased over the past decade. However, little is known regarding the source of the misused stimulants and whether different sources correspond to differences in risk profiles and associated social and health problems.

METHOD

Data from the 2006 to 2011 National Survey on Drug Use and Health were used. A total of 4945 participants who used prescription stimulants nonmedically and also reported their source of misused stimulants were categorized by the source: friend/relative, physician and illegal. Logistic regression models compared the socio-demographic, mental health and behavioral problems, and stimulant use-related problems (onset, recency, frequency, severity) according to the source of the misused stimulants.

RESULTS

The most common sources of stimulants were friends/relatives, followed by physicians and illegal sources. Compared to participants reporting friends/relatives as the source, participants reporting an illegal source were more likely to be male, unemployed, have less than a high school education, a history of criminal behavior and an earlier age of use onset. Participants reporting a physician source were more likely to have mental health problems and mental health service use. Higher odds of past-month stimulant use, frequent use (≥ 10 days per year), drug dependence and substance service use were found in individuals reporting physician and illegal sources.

CONCLUSIONS

Identifying the source of misused stimulants may be useful in detecting distinct subgroups of nonmedical prescription stimulant users, which may inform development of tailored prevention and treatment programs and contribute to individual treatment planning.