Cons of Ritalin for Adults with ADHD
While Ritalin has been approved for use in childhood ADHD, the Food and Drug Administration has not approved use of this drug for use in adults with ADHD (Ritalin has been approved for use in adults with narcolepsy, states eMedTV). 
This medication has not been sufficiently studied for use in adults with ADHD –– the risks and benefits of this medication for treatment of ADHD in adults has not been determined in any large-scale studies.
The adult’s physician is allowed to prescribe Ritalin to treat symptoms of ADHD in an “off-label" use, meaning the FDA permits physicians to prescribe a medication to treat the ADHD in an age group for which the medication has not been explicitly approved. 
In addition, in some cases of adult ADHD Ritalin can be taken for differing amounts of time, if the physician believes the medication may be beneficial to his patient.
Because some adults with ADHD have additional health problems, such as high blood pressure, congestive heart failure or heart disease, these adults and their doctors must use caution in choosing medications to treat the ADHD. A cautious physician will ensure that his adult patient with ADHD does not have any of these conditions before prescribing any stimulant medication, according to eMedTV.