Evaluating the Methylphenidate Patch to Treat Former Stimulant Users With ADHD

Methylphenidate and amphetamines are considered to be the first line of treatment for ADHD in children (Biederman et al, 1997). Although treating children and adolescents with stimulants does not appear to increase the risk of substance use disorders (Wilens et al, 2003), little is known about the abuse of prescription stimulants in adults with ADHD. A review of the literature on the abuse potential of methylphenidate in animals and humans found that methylphenidate produced reinforcing, discriminative-stimulus, and subjective effects similar to amphetamines or cocaine (Kollins et al, 2001). Although the abuse rates of methylphenidate and other stimulant medications used for the treatment of ADHD have not been empirically established, significant concern exists so that regulatory mandates are enforced to control distribution, and some physicians may be reluctant to use stimulants in patients with drug abuse histories. The introduction of a methylphenidate patch is an important advancement, as the patch formulation should increase compliance while minimizing abuse potential, making it an attractive treatment option in the large population of individuals who have a history of previous drug misuse. The primary aim of this study is to assess the efficacy of the methylphenidate patch in adult individuals with ADHD who have abused stimulants in the past. It is hypothesized that the methylphenidate patch will be efficacious in reducing ADHD symptoms in this population.

Inclusion criteria

• Healthy men and women, 18 to 65 years of age
• Meet DSM-IV criteria for past stimulant (cocaine, methamphetamine, or prescription stimulant) abuse or dependence, with past abuse/dependence defined as a minimum of three months since meeting DSM-IV criteria, or have exhibited a pattern of stimulant misuse. For the purposes of this study, stimulant misuse will be defined as using someone else's stimulant ADHD medication for a minimum of four times in a one-month period, and this misuse must have occurred for at least three months.
• Meet DSM-IV criteria for current ADHD, determined by a clinical interview and confirmed by semi-structured interview with the Conners' Adult ADHD Diagnostic Interview for DSM-IV (CAAR-D; Conners et al, 1999)
• ADHD symptom severity indicated by a score of 12 or greater on the Wender-Reimherr Adult Attention Deficit Disorder Scale
• All subjects will agree to and sign a written, IRB-approved informed consent
• Subjects must live within a 60-mile radius of Charleston, SC, to facilitate study visit compliance

Exclusion criteria

• Individuals meeting DSM-IV dependence for any substance with the exception of nicotine and caffeine
• Individuals meeting DSM-IV criteria for a lifetime history of schizophrenia or another non-affective psychotic disorder or bipolar disorder, since these patients will most likely be taking other psychotropic medications and often require intensive psychiatric care
• Individuals meeting DSM-IV criteria for current major depressive disorder or eating disorder, since these individuals will likely require treatment with psychotropic medications.
• Individuals who present significant suicidal risk
• Individuals with significant cognitive impairment as measured by a score of less than 26 on the Mini-Mental Status Exam, as they may be unable to understand the informed consent, comply with study protocol, or accurately complete assessments
• Individuals currently receiving stimulants, benzodiazepines, antidepressant or antipsychotic medications.
• Individuals currently receiving psychotherapy focusing on reducing ADHD symptoms, as this could confound the effects of methylphenidate treatment
• Pregnant or nursing women, or women who refuse to use adequate birth control, as methylphenidate has not been approved for use in pregnancy
• Individuals without stable housing, as contacting these individuals would be difficult
• Individuals with major medical illnesses (e.g., HIV, renal failure, unstable angina, chronic obstructive pulmonary disease, infectious hepatitis)
• Patients with uncontrolled hypertension (defined as having blood pressure greater than 140/90 measured on 3 or more occasions), as methylphenidate treatment can be associated with increases in blood pressure
• Individuals with a significant family history of cardiac abnormalities, as these individuals may be more susceptible to cardiac adverse events
• Individuals who are obese (greater than 30% over ideal weight or BMI greater than 30) as this may interfere with absorption of methylphenidate
• Individuals who, in the investigators' opinion, would not be able to comply with study procedures, such as individuals unable to reliably present for intake appointments