Methylphenidate
A first-line prescription stimulant for ADHD and narcolepsy, marketed as Ritalin and the extended-release Concerta. It blocks dopamine and noradrenaline reuptake, improving attention and impulse control. Decades of controlled trials support efficacy, but it carries dependence potential, cardiovascular load, appetite suppression and insomnia.
01 Overview
Methylphenidate is one of the most studied psychostimulants in medicine, with efficacy in ADHD established across hundreds of randomised trials in children and adults. Immediate-release forms last 3-4 hours; extended-release formulations (Concerta, Ritalin LA) provide once-daily coverage.
It is a Schedule II controlled substance in the US because of abuse and diversion potential, though the risk at therapeutic oral doses is lower than with amphetamines. Common trade-offs include reduced appetite, delayed sleep onset, modest increases in heart rate and blood pressure, and rebound irritability as doses wear off.
02 Mechanism
Blocks the dopamine transporter (DAT) and noradrenaline transporter (NET), increasing synaptic dopamine and noradrenaline in the prefrontal cortex and striatum.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Extended-release (Concerta) | 18–72 mg/day | Oral | Once-daily; osmotic-release delivery for ~12-hour coverage. |
| Therapeutic (adult ADHD) | 20–60 mg/day | Oral | Immediate-release usually split into 2-3 daily doses; titrated from a low start. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Improved attention and impulse controlConsistently reduces core ADHD symptoms in controlled trials across age groups. | Large effect size in ADHD | Clinical | |
| Increased wakefulness and focusEnhances sustained attention and reduces daytime sleepiness, including in narcolepsy. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Appetite suppression and weight lossReduced appetite is among the most frequent effects, and can slow growth in children. | Moderate | Very common | Clinical | |
| InsomniaDelayed sleep onset, particularly with late-day dosing. | Moderate | Common | Clinical | |
| Increased heart rate and blood pressureModest elevations in heart rate and blood pressure; caution in pre-existing cardiac disease. | Moderate | Common | Clinical |