Stimulant and Non-Stimulant Drugs for Adult ADHD
Stimulant-type drugs continue to be the drug of choice for both children and adults with ADHD. Most medication formulations are derived from one of two sources: methylphenidate or amphetamine. There are about 14 products currently available in the US: Some are immediate-release. Others are extended-release formulations.
One of the most desirable qualities of stimulants is that they work quickly. Beneficial effects begin within 20 minutes of dosing and last up to 3 to 4 hours. Extended release formulations are designed to last longer. The choice between short-acting and extended release is related to lifestyle, age, home environment, personal preference, etc. Each has advantages and disadvantages. Some people even use both types. As we will discuss, the right type, dose, and schedule usually requires trial and error, in close consultation with the prescriber.
Stimulant-type drugs operate in the central nervous system. They work by increasing the brain chemicals dopamine and norepinephrine. This is achieved by blocking the reuptake (i.e., the reabsorption) of dopamine and norepinephrine in the brain. This makes these substances more available for a longer period of time. They may also block some of the metabolic enzymes that try to absorb loose dopamine and additionally stimulate increased production. Thus, pharmacologically such medications serve to increase concentrations of both chemical neurotransmitters.
These drugs do have a potential for abuse. In the United States, stimulants are considered Class II medications. Therefore, their use is monitored by the federal government via the Drug Enforcement Agency (DEA). Physicians who prescribe these medications must follow special procedures to limit potential for drug misuse. For example, prescriptions must be written rather than phoned into a pharmacy. Only a one-month supply can be dispensed at a time. Extended-release products are generally recommended, particularly in adults and teens. For most people, extended release drugs are easier to use and to dose correctly. This ease facilitates a collaborative treatment approach, while minimizing the potential for drug abuse.
Research has shown that at least 70% of people taking stimulants for ADHD have positive results (Biederman and Spencer, 2004). Frequently prescribed stimulants include:
- Methylphenidates (e.g., Ritalin, Concerta, Metadate, Focalin) - This family of stimulants is used to treat both ADHD and narcolepsy.
- Dextroamphetamines (e.g., Dexedrine, Vyvanse)
- Amphetamines (e.g., Adderall). Adderall was approved by the FDA in the 1960's for the treatment of obesity and ADHD.
Non-stimulant drugs for ADHD
Non-stimulant medications generally have less impressive effectiveness in ADHD treatment when compared with stimulants. Therefore, they are prescribed less frequently. Initial ADHD treatment usually begins with stimulant medications unless contraindicated (e.g., patient with cardiac abnormalities, or a history of substance abuse). Typically, non-stimulant medication is tried after unsatisfactory results using stimulants. Non-stimulant ADHD medications that are currently available include:
- Strattera (Atomoxetine), immediate- and extended-release;
- Clonidine; and,
If you would like more specific details about each medication, please see our companion article on ADHD in children.