Amphetamines and their Effect on ADHD
Testing ADHD medicine efficacy
Background
Amphetamines are part of a class of drugs known as central nervous system stimulants, which increase the reaction time of the messages sent between the brain and the body. These are distributed and used in both legal and illegal manners. Legal usage of amphetamines is through prescription by a medical doctor, typically for the conditions attention-hyperactivity-disorder (ADHD) and narcolepsy (an uncontrollable urge to sleep at improper times). Common names for prescription amphetamines are Adderall, Dexedrine, Vyvanse, and Desoxyn. Illegal usage of amphetamines is when distributed without a doctor’s consent, and for usage that is not for a medical diagnosis. These often present in methamphetamine (meth) form, which produces an energetic and altered state called a “high.”
More research is now being conducted on legal usage of amphetamines to treat ADHD. With the increase in ADHD diagnoses, the safety and effectiveness of the treatments used, especially when known to be an addictive substance, is important for the well-being of patients.
Summary
This study tested the effect of ADHD medication on motivation in both physical and mental capabilities. Participants included both individuals that were diagnosed with ADHD along with those who were not. The twenty participants that were diagnosed with ADHD and the twenty-four participants that were not diagnosed with ADHD (which served as the control group), were both instructed to complete a cognitively effortful task and a physically effortful task. The cognitive exercise was the Rapid Serial Visual Presentation (RSVP) test where images are continually shown in the same visual field and the participant is required to indicate every time they see a certain object, which in this case was the letter “T”. The physical task involved the participants exerting varying levels of force on a dynamometer (a hand-held device that measures force).
The participants in the ADHD category were tested on these tasks both with and without their typically prescribed medications. The medications used were dexamfetamine for eight of the participants, and lisdexamfetamine for the remaining twelve, both of which are amphetamine-based. The results of this study were decreased motivation for the ADHD participants without medication in both the physical and cognitive tasks. With the amphetamine-based medications, physical and cognitive motivation was increased in those who were diagnosed with ADHD to levels comparable to the controls who do not have ADHD-related motivation deficits. As seen in the earlier graph, both the physical and cognitive motivation levels drop significantly less when the participants with ADHD were on their medications compared to when they were not, as well as being on par with the control participants.
For future research, the conductors of the study suggest investigating whether the aversion to the effort required of the ADHD participants is related to the cognitive inefficiencies of those who are diagnosed with the disorder. The researchers explain that the effort aversion seen in the ADHD participants is completely independent of their actual capability to perform tasks, and the amphetamine medication restores this ability by improving motivation. Hopefully the research found in this study acts as a starting point of continued research into the field of using amphetamines to increase the well-being of patients with debilitating symptoms of ADHD.
