How you respond to ADHD medication like Adderall may be partially determined by your personality, according to research published online January 23 in the Journal of Psychopharmacology.
Researchers from the University of Chicago and Wayne State University in Detroit found that subjective responses to dextroamphetamine, the main component in several ADHD medications, were related to certain personality traits.
“[P]re-existing differences in personality appear to contribute to the subjective effects of the drug, perhaps because of shared neurochemical systems,” they explained “Individuals with certain personality traits may be more susceptible to the rewarding properties of [dextroamphetamine] and thus may be at greater risk for using the drug repeatedly, and ultimately developing an amphetamine use disorder.”
In particular, the researchers discovered that those who scored highly on a measure of impulsivity tended to experience greater euphoria and arousal. Those who were more sensitive to reward also experienced greater euphoria, while those who reported less physical fearlessness experienced greater arousal.
A few smaller studies have examined the relationship between personality and the subjective effects of d-amphetamine, but the researchers hoped to conduct a larger, more determinative experiment. The researchers recruited 286 healthy adults, who received three different doses of dextroamphetamine along with a placebo.
Previous research has found that two of the personality traits — impulsiveness and reward sensitivity — are linked to the neurotransmitter dopamine. Research has also found the personality trait of fearlessness is linked to the neurotransmitter norepinephrine.
Dextroamphetamine increases the level of both neurotransmitters in the brain, suggesting there is a biological basis underlying the association between personality traits and the subjective effects of the drug. However, the researchers noted other possible explanations for their findings exist and additional research is needed.
“Future laboratory studies might investigate the relationship between trait personality measures, the specific neurobiological underpinnings of these measures, and drug self-administration in order to better understand whether these personality traits mediate drug-taking behavior,” they concluded.
The study was conducted by Matthew G. Kirkpatrick and Harriet de Wit of the University of Chicago, and Chris-Ellyn Johanson of Wayne State University.