Why dopamine makes people more impulsive

This week, my guest article on the neuroscience education site Knowing Neurons examines why drugs that enhance levels of the neurochemical dopamine make people more impulsive – that is, more likely to choose short-term gratification rather than think in the long-term. This concerns both recreational drugs such as cocaine and alcohol, as well as medical treatments for Parkinson’s disease, which either boost dopamine production (eg. L-DOPA) or stimulate dopamine receptors (eg. apomorphine). In my piece, I also explore the scientific evidence that individuals who are innately more impulsive than others might have stable life-long differences in various components of their brains’ dopamine systems.

Dopamine

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2 thoughts on “Why dopamine makes people more impulsive

  1. Thank you very much for this comprehensive review…

    Is there something known about the reward/ delay impulsiveness /dopamine stuff and ADHD??
    And I woul add ADHD drugs ( particularly psychostimulants)

    ( I’ m a family physician working with ++++ ADHD kids)

    Thanks in advance

    Yves Lambert

    Like

  2. Yves Lambert,
    the relationship between dopamine and reward has indeed been implicated as relevant for ADHD as well, both in terms of a generally reduced processing of rewards (lower amplitude of dopamine spikes)*, as well as as a particular problem of delaying gratification (lower amplitude of anticipatory dopamine spikes)**.
    Put bluntly: More severe cases of ADHD seem to come with an increased tendency to get bored quickly and a failure to learn what predicts upcoming reward, hence a tendency to seek immediate gratification and to have trouble continuing to attend to the current task.
    As a physician, you sure know that Adderall, the typical “treatment” for people with ADHD, directly acts on the dopamine system by stimulating its release and inhibiting its reuptake, thereby increasing overall dopamine concentration. Interestingly, on people with ADHD this appears to have an effect very different from what taking amphetamines has on neurotypical individuals – when I first tried Adderall, my first reaction was that I felt like going to sleep.
    (I don’t actually take Adderall, though, as a higher dosage in different circumstances changed my perception in an indescribable way, which made me extremely uncomfortable. I find that having very strict routines (outside of which I tend to be quite dysfunctional) is a much better way of dealing with ADHD, especially after having experienced the massive difference between what someone with ADHD can be like on and off Adderall in friends.)

    * Plichta, Michael M., et al. “Neural hyporesponsiveness and hyperresponsiveness during immediate and delayed reward processing in adult attention-deficit/hyperactivity disorder.” Biological psychiatry 65.1 (2009): 7-14.
    http://www.sciencedirect.com/science/article/pii/S0006322308008275
    ** Tripp, Gail, and Jeff R. Wickens. “Research review: dopamine transfer deficit: a neurobiological theory of altered reinforcement mechanisms in ADHD.” Journal of child psychology and psychiatry 49.7 (2008): 691-704.
    http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7610.2007.01851.x/full

    Liked by 1 person

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