Reinforcing and subjective effects of methylphenidate in adults with and without attention deficit hyperactivity disorder (ADHD)

Abstract

Rationale There has been controversy over the abuse potential of methylphenidate (MPH) in the context of treatment for attention deficit hyperactivity disorder (ADHD). Objective The objective of this study was to compare the reinforcing and subjective effects of oral MPH in adults with and without ADHD. Materials and methods Following screening, 33 adults (n= 16 with ADHD; n=17 free from psychiatric diagnoses) completed four pairs of experimental sessions, each of which included a sampling session and a self-administration session. During sampling sessions, subjects received in randomized order 0 (placebo), 20, 40, and 60 mg MPH. During self-administration sessions, subjects completed a progressive ratio (PR) task to earn portions of the dose received on the corresponding sampling session. Subjective effects were recorded throughout all sessions. The main outcome measure for the study was the number of ratios completed on the PR task. Secondary measures included peak subjective effects and area-under-the-curve values for subjective effects. Results Compared to the control group, the ADHD group completed more ratios on the PR task. Both groups showed robust effects of methylphenidate on subjective endpoints. Main effects of group were noted on subjective effects involving concentration and arousal. Conclusions Compared to placebo, MPH produced reinforcing effects only for the ADHD group and not for the control group. Increases in stimulant-related subjective effects in non-ADHD subjects were not associated with drug reinforcement.

Differences in Methylphenidate Dose Response between Periadolescent and Adult Rats in the Familiar Arena-Novel Alcove Task

“…The function of the dopamine transporter and consequently the effects of methylphenidate appear to be altered in individuals with ADHD compared with those in individuals without the disorder (Mazei-Robison et al, 2008). Consistent with that finding, self-administration of methylphenidate in humans produced reinforcing effects in normal adults but not in adult subjects with ADHD (Kollins et al, 2009). Further studies must be conducted to determine whether the observed effects of the drug in this study also reflect the drug's effects in ADHD or are limited to the normal brain.…”

Single Dose Methylphenidate Does Not Impact on Attention and Decision Making in Healthy Medical Students

“…Alternatively, healthy individuals may choose to use this drug because of its subjective effect on perception of self confidence, [11] sense of concentration, [15] alertness and vigor, fatigue [6,8], mood [6] and well being [9,16,17].…”

Subjective Effects, Misuse, and Adverse Effects of Osmotic-Release Methylphenidate Treatment in Adolescent Substance Abusers with Attention-Deficit/Hyperactivity Disorder

“…Laboratory studies completed with normal adults ) and adults with a history of recreational stimulant use (Parasrampuria et al 2007) suggest that positive subjective effects, which are considered indicators of abuse liability, are significantly lower for OROS-MPH compared with immediate release (IR)-MPH. Laboratory doubleblind choice procedure and self-administration studies of IR-MPH in children and adults with ADHD suggest that although individuals with ADHD choose IR-MPH more than placebo, this selection is related to the therapeutic, rather than the euphoric, effects of the medication Kollins 2004, 2005;Kollins et al 2009). Given the generally low abuse liability of OROS-MPH, it was predicted that the euphoric subjective effects of OROS-MPH would not differ significantly from those of placebo and would not differ as a function of baseline substance use severity and that adolescent ratings would not significantly differ from adult ratings.…”

“…Previous research has found that the likeability of psychostimulants in individuals with ADHD is associated more with therapeutic effect than with euphoric effects Kollins 2004 2005;Kollins et al 2009). Results from the present analyses are consistent with this research in that the correlation between medication liking and treatment effectiveness was stronger than the correlation between liking and high for both the adolescent and adult samples.…”