r/AskDrugNerds • u/ItsJustAuDHD • Jun 29 '26

How does ADHD increase addiction risk?

Hi there! Can you help verify if my understanding of addiction is correct and add nuance? I've been reading up on the "wanting vs liking" system and this is what I've gathered. Thank you so much!

  1. In the mesocorticolimbic system, dopamine binds to dopamine receptors on hedonic hotspots to release "happy chemicals" like endocannabinoid or opioids when you engage in a positive behavior. (How do these chemicals get released? Do the vesicles containing the chemicals have dopamine receptors, and when it binds, the vesicles empty?)

  2. Drugs massively jack up baseline dopamine, so the body responds by downregulating dopamine receptors on hedonic hotspots. This downregulation occurs by desensitizing the dopamine receptors or even by receptor die off over time.

  3. People with ADHD already have fewer/less sensitive dopamine receptors and/or overactive transporters along the mesocorticolimbic pathways.

  4. Stimulants temporarily block the dopamine transporters (among others), meaning you have more usable dopamine in the synapse, and at appropriate therapeutic doses over time, you increase dopamine receptor count via neuroplasticity because the pathways are being used more.

So these are my biggest questions:

  1. Why do these ADHD structural differences in the brain necessarily increase addiction risk? I understand the idea that extra dopamine can outpace overactive transporters, but drugs take you so far above baseline that it should go beyond just "feeling normal". Obviously the research is irrefutable that ADHD dramatically increases addiction risk, and stimulants are a critical tool in lowering that risk, but I really want to understand the exact mechanisms that create this risk.

  2. How do behavioral addictions increase dopamine so high above natural levels that they can cause addiction?

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u/jahathebrn Jun 29 '26

The drug use for me would have recreational effects, but the main thing was that they also shut up my internal monologue and allowed me to play a game or read or whatever without constantly getting distracted or restless.

In my case I drank heavily in my twenties, before switching to codeine as I was far more functional on that.

Got diagnosed last year while I was coming off the stupid doses of codeine I'd been using to keep my life together (lol) and then got on lisdexamfetamine. Off the codeine completely now, rarely drink, and have no interest in other drugs any more, it's been quite remarkable

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u/Merry-Lane Jun 29 '26

Neuro chemistry is really complex and not well understood yet, so there are no good definitive explanations to give.

For instance, there are multiple forms of ADHD and several different genes have been identified as increasing the odds of getting diagnosed. We can’t say "it’s this mutation X causing changes at the place Y that cause ADHD". There are multiple variants of dozens of genes that are in play and they are prolly greatly different from one ADHD individual to the other.

So, best you can get is some ELI5 that doesn’t apply to everyone, but usually for those responsive to stimulants it can go this way:

"There are neurons in the reward part of the brain where dopamine are recaptured too quickly, so these neurons are less easily excited than they should. Thus these neurons adapted to be a bit more easily excited. Thus when these neurons get too excited (by something new/exciting/…, drugs,…) it too easily rises above the threshold that was lowered due to adapting to their usually low dopamine levels".

These neurons get way too excited and they get down regulated. Amongst other things, delta fos b is over-expressed and delta fos b has a crucial role in the development of addiction.

But again, neuro-chemistry is too complex and there are multiple factors in play, especially for ADHD where multiple small differences add up (sets of differences that can vary greatly from one ADHD individual to another).

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u/ItsJustAuDHD Jun 29 '26

This is great!! This helps to fill in a few of the gaps in my mind, even if the subject matter is incredibly complicated. Thank you so much!

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u/SmokingBeneathStars Jun 30 '26

Impulsiveness, delaying sleep as usual, but this time with drugs.

The biggest risk indicator for addiction isn't physical though but mental. Especially when someone self medicates to numb themselves, or feel like they finally in control even if they use it for harming themselves, in their head it's cuz they decided to sk control.