Association between Attention Deficit Hyperactivity Disorder Medication and Depression: A 10-year Follow-up Self-controlled Case Study.

Previous studies have suggested that risk of psychotic events may be increased in children exposed to methylphenidate (MPH). However, this risk has not been fully examined, and the possibility of confounding factors has not been excluded. Patients aged 6–19 years who received at least one MPH prescription were identified using Hong Kong population-based electronic medical records on the Clinical Data Analysis and Reporting System (2001–2014). Using the self-controlled case series design, relative incidence of psychotic events was calculated comparing periods when patients were exposed to MPH with non-exposed periods. Of 20,586 patients prescribed MPH, 103 had an incident psychotic event; 72 (69.9%) were male and 31 (30.1%) female. The mean age at commencement of observation was 6.95 years and the mean follow-up per participant was 10.16 years. On average, each participant was exposed to MPH for 2.17 years. The overall incidence of psychotic events during the MPH exposure period was 6.14 per 10,000 patient-years. No increased risk was found during MPH-exposed compared with non-exposed periods (incidence rate ratio (IRR) 1.02 (0.53–1.97)). However, an increased risk was found during the pre-exposure period (IRR 4.64 (2.17–9.92)). Results were consistent across all sensitivity analyses. This study does not support the hypothesis that MPH increases risk of incident psychotic events. It does indicate an increased risk of psychotic events before the first prescription of MPH, which may be because of an association between psychotic events and the behavioural and attentional symptoms that led to psychiatric assessment and initiation of MPH treatment.

Characterization of anxiety-related responses in male rats following prolonged exposure to therapeutic doses of oral methylphenidate

Prospective follow-up studies found no chromosomal mutagenicity of methylphenidate therapy in ADHD affected children

Acute and long-term effects of adolescent methylphenidate on decision-making and dopamine receptor mRNA expression in the orbitofrontal cortex

Patients with attention-deficit/hyperactivity disorder (ADHD) are at an increased risk of attempting suicide. Stimulants, such as methylphenidate hydrochloride, are the most common treatment for ADHD, but the association between their therapeutic use and suicide is unclear. To investigate the association between methylphenidate and the risk of suicide attempts. A population-based, electronic medical records database from the Hong Kong Clinical Data Analysis & Reporting System was used to identify 25 629 individuals aged 6 to 25 years who were treated with methylphenidate between January 1, 2001, and December 31, 2015. Those who had attempted suicide were included in the analysis. A self-controlled case series design was used to control for time-invariant characteristics of the patients. Relative incidence of suicide attempt during periods when patients were exposed to methylphenidate compared with nonexposed periods. Among 25 629 patients with methylphenidate prescriptions, 154 had their first recorded suicide attempt within the study period; of these individuals, 111 (72.1%) were male; mean (SD) age at baseline was 7.15 (2.19) years. The overall incidence of suicide attempts during methylphenidate treatment was 9.27 per 10 000 patient-years. An increased risk of suicide attempts was detected during the 90-day period before methylphenidate was initiated, with an incidence rate ratio (IRR) of 6.55 (95% CI, 3.37-12.72). The IRR remained elevated during the first 90 days of treatment (IRR, 3.91; 95% CI, 1.62-9.42) before returning to baseline levels during ongoing treatment (IRR, 1.35; 95% CI, 0.77-2.38). When the risk during the first 90 days of treatment was compared with the 90 days preceding first treatment, the incidence of suicide attempts was not elevated (IRR, 0.78; 95% CI, 0.26-2.35). The incidence of suicide attempts was higher in the period immediately before the start of methylphenidate treatment. The risk remained elevated immediately after the start of methylphenidate treatment and returned to baseline levels during continuation of methylphenidate treatment. The observed higher risk of suicide attempts before treatment may reflect emerging psychiatric symptoms that trigger medical consultations that result in a decision to begin ADHD treatment. Therefore, this study's results do not support a causal association between methylphenidate treatment and suicide attempts.

Discontinuation of methylphenidate after long-term exposure in nonhuman primates

Methylphenidate (MPH) is among the main drugs prescribed to treat patients with attention-deficit and hyperactivity disease (ADHD). MPH blocks both the norepinephrine and dopamine reuptake transporters (NET and DAT, respectively). Our study was aimed at further understanding the mechanisms by which MPH could modulate neurotransmitter efflux, using ex vivo radiolabelled neurotransmitter assays isolated from rats. Here, we observed significant dopamine and norepinephrine efflux from the prefrontal cortex (PFC) after MPH (100 µM) exposure. Efflux was mediated by both dopamine and norepinephrine terminals. In the striatum, MPH (100 µM) triggered dopamine efflux through both sodium- and vesicular-dependent mechanisms. Chronic MPH exposure (4 mg/kg/day/animal, voluntary oral intake) for 15 days, followed by a 28-day washout period, increased the firing rate of PFC pyramidal neurons, assessed by in vivo extracellular single-cell electrophysiological recordings, without altering the responses to locally applied NMDA, via micro-iontophoresis. Furthermore, chronic MPH treatment resulted in decreased efficiency of extracellular dopamine to modulate NMDA-induced firing activities of medium spiny neurons in the striatum, together with lower MPH-induced (100 µM) dopamine outflow, suggesting desensitization to both dopamine and MPH in striatal regions. These results indicate that MPH can modulate neurotransmitter efflux in brain regions enriched with dopamine and/or norepinephrine terminals. Further, long-lasting alterations of striatal and prefrontal neurotransmission were observed, even after extensive washout periods. Further studies will be needed to understand the clinical implications of these findings.

Methylphenidate (MPH) is a psychostimulant used in the treatment of attention-deficit/hyperactivity disorder in children and adults. Increasing abuse rates of this drug have raised questions regarding the effects of chronic, high-dose MPH administration. Although the effects of chronic MPH exposure have been well-documented in regard to reward-related behaviors in adolescent and adult animals, there are few studies of the effects of MPH on depressive-like behaviors and antidepressant responses, particularly in adult models. We examined the effects of chronic (14 days) high-dose (20 mg/kg i.p.) MPH exposure on locomotor activity and forced swim test behavior in C57Bl/6J mice. We show that MPH treatment ameliorates the locomotor suppression seen in response to fluoxetine. In addition, chronic MPH treatment produces depressive-like effects in the forced swim test, with decreased latency to first immobility and a trend toward increased immobility. These effects are reversed with acute fluoxetine administration, in contrast to saline-treated animals, which show no response to fluoxetine. The induction of depressive-like behaviors after chronic MPH treatment in adult mice is in agreement with previous studies in adolescent rats, and the marked alterations in fluoxetine responses implicate alterations in the serotonin system and possibly the dopamine system produced by MPH.

Exposure to methylphenidate (MPH) during adolescence is the elective therapy for attention deficit/hyperactivity disorder (ADHD) children, but raises major concerns for public health, due to possibly persistent neurobehavioral changes. Rats (30- to 44-days old) were administered MPH (2 mg/kg, i.p once daily) or saline (SAL). At the end of the treatment we collected plasma, testicular, liver, and brain (striatum) samples. The testes and liver were used to evaluate conventional reproductive and metabolic endpoints. Testes of MPH-exposed rats weighed more and contained an increased quantity of sperm, whereas testicular levels of testosterone (TST) were markedly decreased. The MPH treatment exerted an inductive effect on enzymatic activity of TST hydroxylases, resulting in increased hepatic TST catabolism. These findings suggest that subchronic MPH exposure in adolescent rats could have a trophic action on testis growth and a negative impact on TST metabolism. We have analyzed striatal gene expression profiles as a consequence of MPH exposure during adolescence, using microarray technology. More than 700 genes were upregulated in the striatum of MPH-treated rats (foldchange >1.5). A first group of genes were apparently involved in migration of immature neural/glial cells and/or growth of novel axons. These genes include matrix proteases (ADAM-1, MMP14), their inhibitors (TIMP-2, TIMP-3), the hyaluronan-mediated motility receptor (RHAMM), and growth factors (transforming growth factor-beta3 [TGF-beta3] and fibroblast growth factor 14 [FGF14]). A second group of genes were suggestive of active axonal myelination. These genes mediate survival of immature cells after contact with newly produced axonal matrix (laminin B1, collagens, integrin alpha 6) and stabilization of myelinating glia-axon contacts (RAB13, contactins 3 and 4). A third group indicated the appearance and/or upregulation of mature processes. The latter included genes for: K+ channels (TASK-1, TASK-5), intercellular junctions (connexin30), neurotransmitter receptors (adrenergic alpha 1B, kainate 2, serotonin 7, GABA-A), as well as major proteins responsible for their transport and/or anchoring (Homer 1, MAGUK MPP3, Shank2). All these genes were possibly involved in synaptic plasticity, namely the formation, maturation, and stabilization of new neural connections within the striatum. MPH treatment seems to potentiate synaptic plasticity, which is an age-dependent developmental phenomenon that adolescent rats are very likely to show, compared to adults. Our observations suggest that adolescent MPH exposure causes only transient changes in reproductive and hormonal parameters, and a more enduring enhancement of neurobehavioral plasticity.

Methylphenidate (MPH) is the most widely prescribed therapy for attention deficit hyperactivity disorder. Animal studies have shown a potential adverse effect of MPH exposure on male fertility. We examined the impact of MPH on human male sperm parameters. Sperm parameters of 9769 samples from patients 18years of age or older, collected as part of the basic evaluation of couples referred to the Infertility Clinic were analyzed retrospectively. We divided the study population into three groups according to MPH purchasing information: MPH purchased ≤ 90days prior to sperm analysis-current users (n = 83), MPH purchased > 90days prior to sperm analysis-past users (n = 293), and MPH-naïve patients (n = 9393). All sperm samples were analyzed by the same laboratory technician team for the following routine parameters: semen volume, sperm concentration, percentage of motile sperm, and percentage of normal morphology according to World Health Organization. The analysis of the samples was completed by evaluation of total sperm count, total sperm motility, and percentage of fast and slow motile cells. Sperm morphology was evaluated by a laboratory technician using methodological examination according to the strict Kruger-Tygerberg criteria. Methylphenidate exposure did not affect sperm morphology but was associated with increased sperm concentration as well as increased total sperm count and total sperm motility among current and past users compared with MPH-naïve patients. In particular, progressive motility and total motile sperm count were significantly increased following MPH use. A multivariate analysis adjusting for age and current smoking was conducted, further supporting a positive correlation between current MPH use and increased values of total sperm count and total sperm motility. Our study has several inherent weaknesses, foremost of which is its retrospective nature. Another notable weakness is that medication purchasing data may not accurately reflect MPH exposure in the study population. Patients may be purchasing MPH and not taking it as prescribed. In the present study, we could not demonstrate a negative impact of methylphenidate treatment on sperm parameters in adults with ADHD. Hence, we may assume that methylphenidate does not negatively affect male fertility.

Methylphenidate effects in the young brain: friend or foe?

Increasing use of ADHD medications in pregnancy.

Geriatric depression is common and is often associated with coexisting medical illnesses, cognitive dysfunction, or both. Treatment with pharmacotherapy is usually required, and many patients may not respond to initial therapy. Thus, there is a need for adjunctive treatment options. The objective of this systematic review is to assess the efficacy and safety of methylphenidate (MPH) in the treatment of geriatric depression. PubMed (1946-December 2020) and Embase (1947-December 2020) were queried using the following search terms: geriatrics, aged, geriatric patient, or elderly and depressive disorder, depression, major depression or late-life depression, and MPH. Studies were included if they were a randomized-controlled trial or open-label trial that investigated use of MPH for treatment of depression in adults aged 60 years and older. After screening per the inclusion criteria, five prospective trials were included. All studies found improvement in depressive symptoms with use of MPH or MPH combined with citalopram. Study durations ranged from 8 to 16 weeks and MPH dosing ranged from 5 to 90mg per day. Based on the reviewed literature, MPH appears to be most effective when combined with citalopram and used short-term. MPH should be initiated at a low dose and titrated up to 10 or 20mg per day based on response. Larger, long-term trials are needed to further define the role of MPH in this population.

To examine clinically important adverse events (AEs) associated with methylphenidate (MPH) treatment of apathy in Alzheimer's Disease (AD) versus placebo, including weight loss, vital signs, falls, and insomnia. The Apathy in Dementia Methylphenidate Trial 2 (ADMET2) trial was a multicenter randomized, placebo-controlled trial of MPH to treat apathy in individuals with apathy and AD. Participants in ADMET2 had vital signs and weight measured at monthly visits through 6months. AEs, including insomnia, falls, and cardiovascular events, were reported at every visit by participants and families using a symptom checklist. The study included 98 participants in the MPH group and 101 in the placebo group. Participants in the MPH group experienced greater weight loss on average than the placebo through the 6-month follow-up, with a difference in change between MPH and placebo of 2.8lb (95% confidence interval, CI: 0.7, 4.9lb). No treatment group differences in change during the trial were found in systolic and diastolic blood pressure. More participants in the MPH group reported falls during the follow-up, 10 versus 6 in MPH and placebo groups, respectively. No differences in post-baseline insomnia were observed between the treatment groups. No participants reported instances of myocardial infarction, congestive heart failure, arrhythmia, stroke, or cardiomyopathy throughout the study period. MPH use in AD patients for treating apathy is relatively safe, particularly notable given the many medical comorbidities in this population. There was a statistically significant but modest weight loss associated with MPH use, and clinicians are thus advised to monitor weight during MPH treatment.

Evaluation of the effect of methylphenidate by computed tomography, electroencephalography, neuropsychological tests, and clinical symptoms in children with attention-deficit/hyperactivity disorder: A prospective cohort study