Adderall is a brand-name pharmaceutical psychostimulant composed of mixed amphetamine salts. The drug is used primarily to treat attention-deficit hyperactivity disorder and narcolepsy. Adderall has also been used successfully to manage severe cases of treatment-resistant depression. Individuals who show little or no response to typical antidepressants--such as the SSRIs and tricyclics--are more likely to respond to psychostimulant therapy. These patients, however, are the exception, rather than the norm amongst depression patients.

Adderall’s inclusion of levoamphetamine provides the pharmaceutical with a quicker onset and longer clinical effect compared to pharmaceuticals exclusively formulated of dextroamphetamine. Although it seems that where the human brain has a preference for dextroamphetamine over levoamphetamine, it has been reported that certain children have a better clinical response to levoamphetamine.

Specifically, Adderall XR is composed of the following proportions of active ingredients:
- 1/4 dextroamphetamine saccharate
- 1/4 dextroamphetamine sulfate
- 1/4 (racemic dextro/laevo-amphetamine) aspartate monohydrate
- 1/4 (racemic dextro/laevo-amphetamine) sulfate

These four salts are metabolized at different rates and possess diverse half lives, therefore resulting in a less dramatic onset and termination of therapeutic action; as compared to single-salt amphetamine preparations.

The average elimination half-life in adults for dextroamphetamine and levoamphetamine is 10 hours and 13 hours respectively. Breakdown rates are affected by many factors including urinary and stomach pH, weight, gender, other medications being taken, and age.

Urinary and stomach pH levels can have the strongest effect on DL-amphetamine excretion and absorption. Co-administration of acidic substances (e.g. citric acid) causes an accelerated excretion of DL-amphetamine while co-administration of alkaline agents (e.g. antacids) causes a marked increase in both retention and absorption of amphetamines potentially resulting in dangerously high serum amphetamine levels.

Adderall`s effects are similar to other CNS stimulants of the same class and preparation.

Adderall generic equivalents/alternatives
The closest generic equivalent to Adderall is dextroamphetamine sulfate also known as Dexadrine and available in a sustained release form called Dexedrine ER. It should be noted that Adderall uses \"mixed amphetamine salts\" and Dexadrine is a single salt therefore Dexedrine ER is not a strict generic equivalent for Adderall XR, though it may, in terms of physiological and psychological effects, be a de facto generic alternative. The savings between Adderall XR and generic Dexedrine ER are significant: 90 dextroamphetamine extended-release capsules cost $20 at a retail pharmacy in the United States, while the equivalent 90 Adderall XR capsules cost $270. The difference is due to the fact that Adderall is still protected under patent in the United States. Until this patent expires, generic versions of Adderall XR will not become available.

Vyvanse is a derivative of Dexedrine, yet it behaves differently in the body (see Dextroamphetamine at \"Formulations\"). The manufacturer has added extra ingredients (in the case of Adderall) or created a prodrug (a precursor) of dextroamphetamine (in the case of Vyvanse) in order to patent allegedly \"improved\" products that are similar to Dexedrine yet cannot be produced generically for the time being.