Meme of the week: the value of dopamine

Whenever a discussion about adhd comes up, there’s a strong likelihood that you’ll hear something about dopamine. The meme above does a good job at representing how many of us characterize the role of dopamine: that is… everything we, as people with adhd, do is designed to squeeze that little extra bit of dopamine out of the substantia nigra, the midbrain region that is responsible for much of the brain’s dopamine production. It is not uncommon to hear clients refer to their efforts in certain contexts as “dopamine mining.”

Mining

I mean… we know that adhd has something to do with a deficit of dopamine, right? That is one of the things that every knows about adhd. After all, the first line medications that are extremely effective in treating people with adhd—a class of medications called psychostimulants—have an effect on dopamine production. So, it follows that adhd is a phenomenon characterized by lower levels of dopamine production.

But maybe not. This is not to say that dopamine doesn’t play a role in the ways people with adhd struggle, but dopamine is not the sole cause. In fact, it may not even be the main cause. The book on the mechanisms underlying adhd is still yet to be written. But we do know some things about adhd that should at least broaden our understanding of the phenomenon.

How do I know that dopamine isn’t the sole or main causal force that produces all the aspects of adhd that we all know and love? The first is that there are some medications that we refer to as dopaminergic—increasing the amounts of dopamine in the brain through a variety of mechanisms—that have little or no effect on people with adhd. If adhd was simply a deficit of dopamine, there are a variety of medications that are dopamine agonists or dopamine reuptake inhibitors that seem to have very little effect on those with adhd. The most common amongst these medications is bupropion, which is better known as Wellbutrin. Wellbutrin is a medication that is classified as a noradrenaline and dopamine reuptake inhibitor and may also cause the release of these neurotransmitters. If dopamine is the problem and target of pharmacotherapy, then Wellbutrin should be a game changer: it’s relatively inexpensive, it’s non-habit forming, it is pro-sexual in its side effects, and it has a long half life, meaning you only need to take it once a day. These are all the features of a medication that would be ideal for those of us with adhd… except for the fact that it doesn’t work very well (or at all).

As someone who has spent many thousands of hours talking with clients with adhd, I can tell you that I have yet to meet a single one who had anything positive to say about Wellbutrin. This is certainly not to say that every client has tried Wellbutrin, but it is a very common medication and many clients are taking it or have taken it. So what gives? If dopamine is the culprit and we have an accessible medication that upregulates dopamine, why isn’t it effective?

As I mentioned earlier, the book on adhd is yet to be written, but I am confident that when it is, dopamine will be a single chapter. It sounds silly to say, but… the brain is complex and focusing on a single molecule in said complex system is reductive. So why do methylphenidate and amphetamine, the two medications that offer the best results in people with adhd, work? Don’t they also have an effect on dopamine levels in the brain? They do, but they also have profound effects on other neurotransmitters in the brain.

Unlike Wellbutrin, the effect of which is limited to noradrenaline and dopamine, methylphenidate and amphetamine have important effects on the excitatory and inhibitory neurotransmitters, glutamate and gaba respectively. Psychostimulants also have a mild effect on serotonin metabolism.

MiningBut we’re getting a bit too far into the weeds here. My point is simply to say that adhd is much more complex than a simple deficit of a single neurotransmitter. This is the reason why dopamine mining is regularly unsuccessful: i.e. not because you can’t find a healthy vein of dopamine in the activities noted in the meme above, but because dopamine in and of itself is not as valuable as it is vaunted to be.