Methylphenidate (Ritalin, Concerta and others) and amphetamines (Adderall and others). Stimulants used for treatment of attention-deficit hyperactivity disorder (ADHD) and narcolepsy (uncontrollable sleep spells). Increase cognitive performance on certain tasks under conditions of fatigue; may improve planning and one type of working memory; appear to increase functioning on dull, repetitive tasks. Could worsen performance in a subset of users or on complex tasks; cardiovascular complications and seizures, hallucinations and addiction.
Modafinil (Provigil). Newer-generation stimulant for narcolepsy and excessive sleepiness because of shift work or obstructive sleep apnea. Appear to augment mental focus and better performance on a limited set of cognitive measures, such as recall of long strings of numbers. May have a higher potential for addiction than originally thought; may cause serious skin rashes.
Donepezil (Aricept). Treatment for the cognitive defi cits of Alzheimer’s disease; increases the neurotransmitter acetylcholine to improve cognition. Might aid in learning or memory, but overall results are equivocal; may take several weeks to work and is not as widely used off-label as the drugs above. Could cause a slight deterioration in cognitive performance in healthy individuals.
Image Source: pharmacy-technician.net
Source of Information : Scientific American October 2009