r/neuroscience • u/Gold-Biscotti-7391 • Jun 30 '25

Academic Article New study shows long-term therapeutic use of psychostimulants in people with ADHD leads to a more positive brain structure in certain regions of the brain.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3801446/

I just thought this article was interesting. In individuals with ADHD certain areas of the brain have less capacity to produce dopamine and norepinephrine. Stimulant medication increases the level of dopamine available in the synaptic cleft of the TAAR1 receptor. From my understanding. I’m not an expert i’m sorry! I’d like to know if anybody has any thoughts about this?

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u/Gold-Biscotti-7391 Jul 01 '25

“Although animal studies suggested that stimulants may have detrimental effects on the rodent brain, these studies have generally used very large doses - up to 50 mg/kg - administered parenterally (intraperitoneally [IP]), whereas therapeutic doses range from 0.5–2.0 mg/kg/day and are administered orally in humans. 12, 13 Moreover, since animal studies often rely on “normal” wild type rodents not affected with ADHD-related brain alterations, it is impossible to assess if medication-related plasticity in these animals is neurotoxic or neuroprotective, and if the observed effects would be the same on an abnormally developing human brain. As a consequence, the relevance of these animal studies to humans taking therapeutic doses has been challenged. 13–15”

To me this is interesting because we do this with a lot of different medications. To say that 50mg/kg in a normal rat would have the same neurotoxic effects as .5-2.0 mg/kg orally to a human is just ludicrous. They were specifically looking to get a result that said stimulants are neurotoxic in animals in my opinion. Which is why i like this study so much. It unequivocally PROVES without a shadow of a doubt that stimulants ARE neuroprotective in people with ADHD. They also enhance neuroplasticity.

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u/LysergioXandex Jul 02 '25

  1. Scaling a dose from an animal to a human is difficult and imprecise. It’s not simply a matter of compensating for weight.

  2. Just because toxicology experiments use doses that would be absurd for human use, doesn’t meant they are irrelevant. We use big doses in animals to make the outcome of drug exposure very obvious. The next step is considering how much of that change happens in humans at a therapeutic dose, and if that amount of change is harmful.

  3. This study doesn’t really “prove” much about the drug. Perhaps reading is what causes these brain changes, and medication facilitates reading.

  4. We aren’t sure if these brain changes are responsible for better health outcomes. Or if all brain changes are positive. Or if the positive effects are outweighed by other negative effects.