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Intravenous Methylphenidate Abuse
Data are presented from a case series of 22 patients who abused methylphenidate hydrochloride (Ritalin-SR). The abuse pattern and symptoms of toxicity were similar to that seen with cocaine hydrochloride and amphetamine sulfate addiction; yet, the morbidity and mortality seen in this case series...
Methylphenidate and Short-Term Cardiovascular Risk
This cohort study examines the risks of cardiovascular disease after 6 months of methylphenidate treatment in individuals with attention-deficit/hyperactivity disorder.
Methylphenidate Treatment and Risk of Psychotic Disorder
This cohort study of a Finnish national multiyear birth cohort uses instrumental variable analysis to investigate whether methylphenidate alters the long-term risk of psychotic disorder in children with attention-deficit/hyperactivity disorder.
How easy is it to get addicted to methylphenidate?
Hi so I (18m) will start taking prescripted methylphenidate (medikinet) next thursday and i’ve never taken any stimulants (besides caffeine and…
A simple and effective F0 knockout method for rapid screening of behaviour and other complex phenotypes
Zebrafish knockouts can be generated in a few hours directly from wild-type eggs and are suitable for studying continuous traits, including behaviour.
Generalization of beneficial exposure effects to untreated stimuli from another fear category
Previous research has shown that fear associated with one stimulus often spreads to other stimuli with similar perceptual features as well as across different stimulus categories. Exposure is considered as the most effective intervention to attenuate exaggerated fear. The extent to which exposure treatment effects can generalize to fears not targeted during treatment remains elusive. Previous studies on possible generalization of beneficial effects of exposure used stimuli sharing the same stimulus category and/or stimuli having high perceptual similarity. The current study examined whether exposure treatment generalization can be achieved for untreated stimuli which do not share any perceptual resemblance and belong to a different fear category. An analogue sample of fifty participants with fear of spiders (animal-related fears) and heights (natural environment-related fears) was tested. Participants have been randomly assigned to either an exposure treatment (n = 24) or a control condition (n = 26). Exposure treatment was designed to only target participants’ fear of spiders, leaving their fear of heights untreated. Results demonstrated that the effects of exposure treatment generalized to fear of heights, as indicated by a reduction in behavioral avoidance, as well as self-reported acrophobia symptoms. The present study confutes the assumption that generalization of exposure effects to untreated fears is based on perceptual similarity. Clearly, further research is required to determine the decisive factors, in order to expand the generalization effect permanently to any given type of fear.
Severe toxicity due to injected but not oral or nasal abuse of methylphenidate tablets
BACKGROUND:Non-medical use of methylphenidate is increasing. Little is known about potential acute medical complications associated with recreational use of methylphenidate. STUDY AIM: To identify medical problems associated with methylphenidate abuse. METHODS: Retrospective case series of methylphenidate abuse cases presenting to an inner city emergency department. RESULTS: We identified 14 cases of methylphenidate abuse between 2003 and 2010. Ten of these patients abused methylphenidate alone while four co-ingested other drugs, mainly alcohol. The route of ingestion was oral in nine patients, nasal in one and intravascular in four. Severe toxicity was exclusively observed in users who injected the drug. Two cases involved accidental intra-arterial injection and resulted in tissue necrosis leading to the amputation of a forearm and of fingertips, respectively. Clinical findings in the non-serious cases included mild to moderate symptoms and signs of sympathetic nervous stimulation such as agitation, tachycardia, hypertension, anxiety, hallucination, headache, tremor and dizziness. Nine of the fourteen patients were taking methylphenidate as a prescribed drug. Eight patients were former or current multiple substance abusers. CONCLUSION: Methylphenidate misuse is not a significant burden for emergency departments in Switzerland. Oral and nasal administration of methylphenidate did not result in severe toxicity. However, injection of crushed methylphenidate pills lead to serious local toxicity. Most patients with methylphenidate abuse had a prescription for the drug indicating deviation from medical use. A history of multiple substance use may be a risk factor for non-medical use of methylphenidate.
Methylphenidate and the risk of psychosis in adolescents and young adults: a population-based cohort study
Background There is a clinical concern that prescribing methylphenidate, the most common pharmacological treatment for attention-deficit hyperactivity disorder (ADHD), might increase the risk of psychotic events, particularly in young people with a history of psychosis. We aimed to determine whether the risk of psychotic events increases immediately after initiation of methylphenidate treatment or, in the longer term, 1 year after treatment initiation in adolescents and young adults with and without a previously diagnosed psychotic disorder. Methods In this cohort study, we used population-based observational data from the Swedish Prescribed Drug Register, the National Patient Register, and the Total Population Register, three population-based registers containing data on all individuals in Sweden, to attain data on sex, birth, death, migration, medication use, and psychotic events for all eligible participants. We screened individuals on these registers to identify those receiving methylphenidate treatment, and who were aged 12–30 years at the start of treatment, for their inclusion in the study. We used a within-individual design to compare the incidence of psychotic events in these individuals during the 12-week periods immediately before and after methylphenidate initiation. Longer term risk was assessed by comparing the incidence of psychotic events 12 weeks before methylphenidate initiation and during a 12-week period one calendar year before the initiation of methylphenidate with the incidence of these events during the 12-week period one calendar year after methylphenidate initiation. We estimated the incidence rate ratios (IRR) and 95% CIs of psychotic events after the initation of methylphenidate treatment, relative to the events before treatment, which were defined as any hospital visit (inpatient admission or outpatient attendance, based on data from the National Patient Register) because of psychosis, using the International Classification of Diseases version 10 definition. Analyses were stratified by whether the individual had a history of psychosis. Findings We searched the Swedish Prescribed Drug Register to find eligible individuals who had received methylphenidate between Jan 1, 2007 and June 30, 2012. 61 814 individuals were screened, of whom 23 898 (38·7%) individuals were assessed and 37 916 (61·3%) were excluded from the study because they were outside of the age criteria at the start of treatment, they had immigrated, emigrated, or died during the study period, or because they were administered other ADHD medications. The median age at methylphenidate initiation was 17 years, and a history of psychosis was reported in 479 (2·0%) participants. The IRR of psychotic events in the 12-week period after initiation of methylphenidate treatment relative to that in the 12-week period before treatment start was 1·04 (95% CI 0·80–1·34) in adolescents and young adults without a history of psychosis and 0·95 (0·69–1·30) among those with a history of psychosis. Interpretation Contrary to clinical concerns, we found no evidence that initiation of methylphenidate treatment increases the risk of psychotic events in adolescents and young adults, including in those individuals with a history of psychosis. Our study should reassure clinicians considering initiating methylphenidate treatment for ADHD in adolescents and young adults, and it challenges the widely held view in clinical practice that methylphenidate should be avoided, or its use restricted, in individuals with a history of psychosis. Funding Swedish Research Council, National Institute of Mental Health, UK National Institute of Health Research Nottingham Biomedical Research Centre.
Effects of Stroop task duration on subsequent cognitive and physical performance
The strength model of self-control purports to explain why brief cognitive response inhibition tasks impair subsequent isometric handgrip endurance. A…
Learning What Substance Is Suspected of Causing Alzheimer’s May Throw You Into an Existential Crisis
A surprisingly common substance was found to have a causal relationship with the kind of brain damage associated with Alzheimer's disease.
4-Fluoromethylphenidate
4-Fluoromethylphenidate is a stimulant drug that acts as a higher potency dopamine reuptake inhibitor than the closely related methylphenidate.
Occurrence of Psychosis and Bipolar Disorder in Individuals With ADHD Treated With Stimulants
This systematic review and meta-analysis evaluates the association between psychosis or bipolar disorder and stimulant treatment among individuals with attention-deficit/hyperactivity disorder.
High intelligence: A risk factor for psychological and physiological overexcitabilities
High intelligence is touted as being predictive of positive outcomes including educational success and income level. However, little is known about the difficulties experienced among this population. Specifically, those with a high intellectual capacity (hyper brain) possess overexcitabilities in various domains that may predispose them to certain psychological disorders as well as physiological conditions involving elevated sensory, and altered immune and inflammatory responses (hyper body). The present study surveyed members of American Mensa, Ltd. (n=3715) in order to explore psychoneuroimmunological (PNI) processes among those at or above the 98th percentile of intelligence. Participants were asked to self-report prevalence of both diagnosed and/or suspected mood and anxiety disorders, attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and physiological diseases that include environmental and food allergies, asthma, and autoimmune disease. High statistical significance and a remarkably high relative risk ratio of diagnoses for all examined conditions were confirmed among the Mensa group 2015 data when compared to the national average statistics. This implicates high IQ as being a potential risk factor for affective disorders, ADHD, ASD, and for increased incidence of disease related to immune dysregulation. Preliminary findings strongly support a hyper brain/hyper body association which may have substantial individual and societal implications and warrants further investigation to best identify and serve this at-risk population.
560 – Ecological Cognition II: Resonance
560 What the heck does the brain do in Ecological Dynamics, if it isn’t computing, processing, or representing? An introduction to the concept of Resonance.Download link
Arsenic exposure at birth, socioeconomic status, and epigenetic aging among adults in northern Chile
Background Arsenic exposure remains a major global health concern, and early-life exposure has been linked to cancer, cardiovascular disease, and diabetes. Epigenetic biomarkers of aging may capture long-term effects of arsenic, yet whether exposure during sensitive developmental windows leaves detectable epigenetic signatures decades later remains unclear. Socioeconomic status (SES) may modify these relationships, yet its role as a modifier has not been examined. Methods We leveraged a natural experiment in northern Chile, where municipal drinking-water arsenic concentrations were extremely high from 1958 to 1972. Decades later, leukocyte DNA methylation was measured among 358 adults (mean age = 65.7 years) using the Illumina EPIC v2 array. Arsenic concentration at birth (0-860 μg/L) was assigned from historical water records. Current exposure was measured in urine (2-646 μg/g creatinine). We evaluated associations of birth and current arsenic exposure with epigenome-wide methylation and epigenetic aging, incorporating multiplicative interaction and stratification by SES. Results No CpGs were linked to birth arsenic exposure, whereas nine CpGs passed the Bonferroni threshold for current urinary arsenic (pBonferroni
Arsenic exposure at birth, socioeconomic status, and epigenetic aging among adults in northern Chile
Background Arsenic exposure remains a major global health concern, and early-life exposure has been linked to cancer, cardiovascular disease, and diabetes. Epigenetic biomarkers of aging may capture long-term effects of arsenic, yet whether exposure during sensitive developmental windows leaves detectable epigenetic signatures decades later remains unclear. Socioeconomic status (SES) may modify these relationships, yet its role as a modifier has not been examined. Methods We leveraged a natural experiment in northern Chile, where municipal drinking-water arsenic concentrations were extremely high from 1958 to 1972. Decades later, leukocyte DNA methylation was measured among 358 adults (mean age = 65.7 years) using the Illumina EPIC v2 array. Arsenic concentration at birth (0-860 μg/L) was assigned from historical water records. Current exposure was measured in urine (2-646 μg/g creatinine). We evaluated associations of birth and current arsenic exposure with epigenome-wide methylation and epigenetic aging, incorporating multiplicative interaction and stratification by SES. Results No CpGs were linked to birth arsenic exposure, whereas nine CpGs passed the Bonferroni threshold for current urinary arsenic (pBonferroni