Stimulants
Stimulants are the most commonly prescribed medications for ADHD. The most common stimulant medications are the chain subsitituted amphetamine methylphenidate (Ritalin, Metadate, Concerta), dexmethylphenidate (Focalin), dextroamphetamine (Dexedrine), mixed amphetamine salts (Adderall), dextromethamphetamine(Desoxyn) and lisdexamfetamine (Vyvanse). According to several studies, use of stimulants (e.g. methylphenidate) can lead to development of drug tolerance to therapeutic doses; tolerance also occurs among high dose abusers of methylphenidate.
Stimulants used to treat ADHD raise the extracellular concentrations of the neurotransmitters dopamine and norepinephrine which causes an increase in neurotransmission. The therapeutic benefits are due to noradrenergic effects at the locus coeruleus and the prefrontal cortex and dopaminergic effects at the nucleus accumbens.
A meta analysis of clinical trials found that about 70 percent of children improve after being treated with stimulants in the short term but found that this conclusion may be biased due to the high number of low quality clinical trials in the literature. There have been no randomized placebo controlled clinical trials investigating the long term effectiveness of methylphenidate(Ritalin) beyond 4 weeks. Thus the long term effectiveness of methylphenidate has not been scientifically demonstrated. Serious concerns of publication bias regarding the use of methylphenidate for ADHD has also been noted.
On occasion, treatment emergent psychosis can emerge during long-term therapy with methylphenidate. Stimulants such methylphenidate should be avoided in people who have a vulnerability to schizophrenia or drug addiction; however, psychotic symptoms may emerge during therapy with methylphenidate in individuals without these risk factors; regular psychiatric monitoring of people who are taking methylphenidate for adverse effects such as psychotic symptomatology (with regard to the need for dose adjustment or discontinuation of medication) has been recommended. Higher rates of schizophrenia and bipolar disorder as well as increased severity of these disorders occur in individuals with a past history of stimulant use for ADHD in childhood.
Both children with and without ADHD abuse stimulants, with ADHD individuals being at the highest risk of abusing or diverting their stimulant prescriptions. Between 16 and 29 percent of students who are prescribed stimulants report diverting their prescriptions. Between 5 and 9 percent of grade/primary and high school children and between 5 and 35 percent of college students have used nonprescribed stimulants. Most often their motivation is to concentrate, improve alertness, "get high," or to experiment.
One review indicates that long-term use of methylphenidate has potential for abuse and addiction due to its similarity pharmacologically to cocaine and amphetamines. However, other doctors argue that use of stimulant therapy for ADHD does not increase the risk of subsequent substance abuse and may be protective against it when treatment is started in childhood. However, when stimulant therapy is started during adolescence or adulthood, there is an increased risk of subsequent substance abuse.
Although "under medical supervision, stimulant medications are considered safe", the use of stimulant medications for the treatment of ADHD has generated controversy because of undesirable side effects, uncertain long term effects and social and ethical issues regarding their use and dispensation. The U.S. FDA has added black-box warnings to some ADHD medications, while the American Heart Association and the American Academy of Pediatrics feel that it is prudent to carefully assess children for heart conditions before treating them with stimulant medications.
A novel stimulant drug that has been used to treat ADHD is modafinil. There have been double-blind randomized controlled trials that have demonstrated the efficacy and tolerability of modafinil, however there are risks of serious side effects such as skin reactions and modafinil is not recommended for use in children.
Stimulants are the most effective medications available for the treatment of ADHD. Five different formulations of stimulants have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of ADHD: three derived from amphetamine and two derived from methylphenidate. Atomoxetine is the only non-controlled, non-stimulant FDA-approved drug for the treatment of ADHD. There are no differences in effectiveness between medications used for ADHD.
Short term clinical trials have shown medications to be effective for treating ADHD, but the trials usually use exclusion criteria, meaning knowledge on medications for ADHD is based on a small subset of the typical patients seen in clinical practice. They have not been found to improve school performance and data is lacking on long term effectiveness and the severity of side effects. This class of medicines is generally regarded as one unit; however, they affect the brain differently. Some investigations are dedicated to finding the similarities of children who respond to a specific medicine. The behavioural response to stimulants in children is similar regardless of whether they have ADHD or not.
Stimulant medication is an effective treatment for Adult Attention-deficit hyperactivity disorder although the response rate may be lower for adults than children. Some physicians may recommend antidepressant drugs as the first line treatment instead of stimulants although antidepressants have lower treatment effect sizes than stimulant medication.
A study showed that children taking stimulant medications tend to be lighter in weight and shorter than their peers. A 2012 study found that among patients (adults and in teenagers over age 15) with a diagnosis of ADHD, their criminality rate during periods of receiving ADHD medication was significantly reduced, compared with nonmedication periods. Criminality consisted of mainly burglary and theft, as opposed to truly violent crimes, like murder.
Read more about this topic: Attention Deficit Hyperactivity Disorder Management, Medications