Methylphenidate is a stimulant drug commonly used in the treatment of attention-deficit hyperactivity disorder, as well as narcolepsy. It gained widespread recognition under the trade name Ritalin from controversy surrounding its use in the treatment of ADHD.
Mechanism of action
Methylphenidate is an indirect catacholamine agonist by blocking the reuptake of dopamine and norepinephrine into the pre-synaptic cell. This increase of neurotransmitters in the synaptic cleft leads to increased neural activity in the striatum.
Usage in ADHD
Methylphenidate is used in the treatment of attention-deficit hyperactivity disorder to reduce locomotor activity, reduce impulsive behaviour, and improve attention. It improves working memory performance by local reduction in cerebral blood flow in the dorsolateral prefrontal cortex and posterior parietal cortex. While the majority of treatment and research is on childhood ADHD, methylphenidate is similarly effective in the treatment of adult ADHD.
The common usage of methylphenidate to treat children with ADHD has prompted concerns that using stimulant medication during a period of development will adversly effect physical and neural growth, as well as predispose them to later substance abuse. Two recent meta-analyses found no evidence for increased future drug use, and even suggest childhood stimulant therapy may reduce the risk of later substance disorders.
- Mehta MA, Owen AM, Sahakian BJ, Mavaddat N, Pickard JD, Robbins TW (2000). "Methylphenidate enhances working memory by modulating discrete frontal and parietal lobe regions in the human brain". J. Neurosci. 20 (6): RC65. PMID 10704519.
- Faraone SV, Spencer T, Aleardi M, Pagano C, Biederman J (2004). "Meta-analysis of the efficacy of methylphenidate for treating adult attention-deficit/hyperactivity disorder". J Clin Psychopharmacol 24 (1): 24–9. DOI:10.1097/01.jcp.0000108984.11879.95. PMID 14709943. Research Blogging.
- Barkley RA, Fischer M, Smallish L, Fletcher K (2003). "Does the treatment of attention-deficit/hyperactivity disorder with stimulants contribute to drug use/abuse? A 13-year prospective study". Pediatrics 111 (1): 97–109. PMID 12509561.
- Wilens TE, Faraone SV, Biederman J, Gunawardene S (2003). "Does stimulant therapy of attention-deficit/hyperactivity disorder beget later substance abuse? A meta-analytic review of the literature". Pediatrics 111 (1): 179–85. PMID 12509574.
The most up-to-date information about Methylphenidate and other drugs can be found at the following sites.