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- Bershad, Anya K., et al.
(författare)
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Effects of MDMA on attention to positive social cues and pleasantness of affective touch
- 2019
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Ingår i: Neuropsychopharmacology. - : NATURE PUBLISHING GROUP. - 0893-133X .- 1740-634X. ; 44:10, s. 1698-1705
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Tidskriftsartikel (refereegranskat)abstract
- The psychostimulant drug +/- 3,4-methylenedioxymethamphetamine (MDMA) reportedly produces distinctive feelings of empathy and closeness with others. MDMA increases social behavior in animal models and has shown promise in psychiatric disorders, such as autism spectrum disorder (ASD) and post-traumatic stress disorder (PTSD). How it produces these prosocial effects is not known. This behavioral and psychophysiological study examined the effects of MDMA, compared with the prototypical stimulant methamphetamine (MA), on two measures of social behavior in healthy young adults: (i) responses to socially relevant, "affective" touch, and (ii) visual attention to emotional faces. Men and women (N = 36) attended four sessions in which they received MDMA (0.75 or 1.5 mg/kg), MA (20 mg), or a placebo in randomized order under double-blind conditions. Responses to experienced and observed affective touch (i.e., being touched or watching others being touched) were assessed using facial electromyography (EMG), a proxy of affective state. Responses to emotional faces were assessed using electrooculography (EOG) in a measure of attentional bias. Subjective ratings were also included. We hypothesized that MDMA, but not MA, would enhance the ratings of pleasantness and psychophysiological responses to affective touch and increase attentional bias toward positive facial expressions. Consistent with this, we found that MDMA, but not MA, selectively enhanced ratings of pleasantness of experienced affective touch. Neither drug altered the ratings of pleasantness of observed touch. On the EOG measure of attentional bias, MDMA, but not MA, increased attention toward happy faces. These results provide new evidence that MDMA can enhance the experience of positive social interactions; in this case, pleasantness of physical touch and attentional bias toward positive facial expressions. The findings are consistent with evidence that the prosocial effects are unique to MDMA relative to another stimulant. Understanding the behavioral and neurobiological processes underlying the distinctive social effects of MDMA is a key step to developing the drug for psychiatric disorders.
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| 2. |
- Mayo, Leah M., 1987-, et al.
(författare)
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Gender differences in the behavioral and subjective effects of methamphetamine in healthy humans
- 2019
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Ingår i: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 236:8, s. 2413-2423
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Tidskriftsartikel (refereegranskat)abstract
- RationaleMethamphetamine (MA) use is steadily increasing and thus constitutes a major public health concern. Women seem to be particularly vulnerable to developing MA use disorder, as they initiate use at a younger age and transition more quickly to problematic use. Initial drug responses may predict subsequent use, but little information exists on potential gender differences in the acute effects of MA prior to dependence.ObjectiveWe examined gender differences in the acute effects of MA on subjective mood and reward-related behavior in healthy, non-dependent humans.MethodsMen (n = 44) and women (n = 29) completed 4 sessions in which they received placebo or MA under double-blind conditions twice each. During peak drug effect, participants completed the monetary incentive delay task to assess reaction times to cues signaling potential monetary losses or gains, in an effort to determine if MA would potentiate reward-motivated behavior. Cardiovascular and subjective drug effects were assessed throughout sessions.ResultsOverall, participants responded more quickly to cues predicting incentivized trials, particularly large-magnitude incentives, than to cues predicting no incentive. MA produced faster reaction times in women, but not in men. MA produced typical stimulant-like subjective and cardiovascular effects in all participants, but subjective ratings of vigor and (reduced) sedation were greater in women than in men.ConclusionsWomen appear to be more sensitive to the psychomotor-related behavioral and subjective effects of MA. These findings provide initial insight into gender differences in acute effects of MA that may contribute to gender differences in problematic MA use.
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| 3. |
- Van Hedger, Kathryne, et al.
(författare)
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Effects of Acute Drug Administration on Emotion : a Review of Pharmacological MRI Studies
- 2021
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Ingår i: Current Addiction Reports. - : SPRINGERNATURE. - 2196-2952. ; 8:2, s. 181-193
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Forskningsöversikt (refereegranskat)abstract
- Purpose of Review Many drug users claim to use drugs to cope with negative emotions, which may, in turn, result in persistent emotional blunting or anhedonia even when they are not using drugs. The purpose of this review is to describe the ways acute administration of psychoactive drugs impacts brain regions during emotion-related tasks, as a first step in understanding how drugs influence emotion processing in the brain. Recent Findings Drugs have varying effects on neural responses to emotional stimuli. In general, alcohol, analgesics, and psychedelics reduce neural reactivity to negative emotional stimuli in the amygdala and other brain regions. Other drugs produce mixed effects: Stimulants such as caffeine and modafinil increase brain activation while viewing emotional stimuli, whereas MDMA decreases activation during presentation of negative images. The effects of cannabinoids (cannabidiol and THC) are mixed. There are also inconsistent findings on the associations between neural responses to emotional stimuli and subjective drug effects. Consistent with the notion that individuals might use drugs non-medically to diminish the experience of negative emotions, several drugs of abuse decrease neural responses to negative stimuli in limbic brain regions. These neural actions may underlie the reported "emotional blunting" of drugs, which may contribute to drug-seeking behavior. Future work is needed to examine these limbic responses in relation to self-reports of changes in affect, both during acute administration and after extended drug use.
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| 4. |
- Van Hedger, Kathryne, et al.
(författare)
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Neural responses to cues paired with methamphetamine in healthy volunteers
- 2018
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Ingår i: Neuropsychopharmacology. - : Nature Publishing Group. - 0893-133X .- 1740-634X. ; 43:8, s. 1732-1737
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Tidskriftsartikel (refereegranskat)abstract
- Drug cues, or conditioned responses to stimuli paired with drugs, are widely believed to promote drug use. The acquisition of these conditioned responses has been well characterized in laboratory animals: neutral stimuli paired with drugs elicit conditioned responses resembling the motivational and incentive properties of the drug itself. However, few studies have examined acquisition of conditioning, or the nature of the conditioned response, in humans. In this study, we used fMRI to examine neural responses to stimuli that had been paired with methamphetamine or placebo in healthy young adults. Participants first underwent four conditioning sessions in which visual-auditory stimuli were paired with either methamphetamine (20 mg, oral) or placebo. Then on a drug-free test day, the stimuli were presented during an fMRI scan to assess neural responses to the stimuli. We hypothesized that the stimuli would elicit drug-like brain activity, especially in regions related to reward. Instead, we found that the methamphetamine-paired stimuli, compared to placebo-paired stimuli, produced greater activation in regions related to visual and auditory processing, consistent with the drugs unconditioned effects on sensory processing. This is the first study to demonstrate conditioned neural responses to drug-paired stimuli after just two pairings of methamphetamine in healthy adults. The study also illustrates that conditioned responses may develop to unexpected components of the drugs effects.
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