Personality and the acute subjective effects of d-amphetamine in humans

Abstract

There is evidence that subjective responses to psychoactive drugs are related to personality traits. Here, we extend previous findings by examining personality measures in relation to acute responses to d-amphetamine (AMPH) in a large sample of healthy volunteers. Healthy adults (n=286) completed the Multidimensional Personality Questionnaire Brief Form (MPQ-BF) and participated in four sessions during which they received oral AMPH (0, 5,10, 20 mg), under double-blind conditions. Subjective responses to the drug were measured using the Profile of Mood States, Addiction Research Center Inventory, and Drug Effects Questionnaire. Drug responses were reduced via principal components analysis to three higher-order factors (‘Euphoria’, ‘Arousal’, ‘Dysphoria’). Participants were rank ordered on selected MPQ-BF scales; the top and bottom third on each trait were compared on the drug response factors. High trait physical fearlessness was significantly associated with greater amphetamine-related Arousal, and high trait reward sensitivity was significantly associated with greater Euphoria. In addition, high trait impulsivity was significantly associated with greater Arousal and Euphoria. These results provide further evidence that individual differences in the subjective effects of AMPH are partially explained by differences in personality, and are consistent with the idea that both personality and responses to stimulants depend upon shared neurochemical systems.

Beyond sensation seeking: a conceptual framework for individual differences in psychostimulant drug effects in healthy humans

“…Laboratory assessments in large samples of healthy volunteers show that measures of trait agentic extraversion can predict euphoria and positive mood responses to moderately high doses of psychostimulants (e.g., Multidimensional Personality Questionnaire (MPQ) social potency). This finding is most consistent at the moderately high dose (20 mg) of d-amphetamine [6] [7]; see also [22]. This relationship appears specific since other traits, such as fearlessness, do not predict euphoria or positive mood to a 20 mg dose [6] [7].…”

“…This finding is most consistent at the moderately high dose (20 mg) of d-amphetamine [6] [7]; see also [22]. This relationship appears specific since other traits, such as fearlessness, do not predict euphoria or positive mood to a 20 mg dose [6] [7]. Lab studies also indicate that trait agency predicts some of the behavioral responses to psychostimulants.…”

“…The positive mood response to stimulant drugs relates both to personality traits such as agentic extraversion [6] [7] and to the amount of dopamine released by the drug in healthy volunteers [24] [25]. Between-subject differences in the magnitude of acute amphetamine effects on positive mood and ‘drug wanting’ are each strongly positively correlated with amphetamine-induced dopamine release in the ventral striatum [25] [24] [26].…”

“…This dopamine response predicts drug effects on positive mood and drug wanting [24] [26]. The positive mood response to amphetamine can be modulated by trait agentic extraversion [6] [23] [7] and other personality traits (fearlessness, impulsivity, absorption; see below). Separately, agentic extraversion has been found to relate to between-person differences in gray matter volumes in the nucleus accumbens, caudate, motor cortex and posterior cingulate [14] – regions involved in drug effects on emotion [24] and behavior [29] [30].…”

The dopamine transporter gene may not contribute to susceptibility and the specific personality traits of amphetamine dependence

“…Different personalities are associated with the propensity of amphetamine abuse (Kirkpatrick et al, 2013;White et al, 2007) and high novelty seeking has been related to an increased risk of addiction (Milivojevic et al, 2012), but the role of AD-related personality traits in the development of AD is unclear. The DAT1 gene was reported to effect personality traits in healthy controls (Kazantseva et al, 2011;Shibuya et al, 2009) and patients with mood disorder (Huang et al, 2011;Joyce et al, 2009), but there are no available data of personality-gene interactions in AD patients.…”