Pain, ADHD, and happiness

I jokingly referred to pain-induced ADD on Monday, but I’m becoming more and more convinced that is actually what was happening.  After prior surgeries I was too exhausted to notice anything, but this time I was energetic enough to experience the pain.  I mean, unless I tried to go outside or something.  That led to a really entertaining systems crash in the supermarket.  But if I stayed inside I was able to do things like get food and put away dishes without strain.  Contrast with when my pain meds sabotaged my cortisol production.  Intellectually I was there and able to do things like read and blog, but physically it was a struggle to make myself a smoothie.

After surgery I could not read or write or even enjoy a movie.  It was more than pain making everything 70% less fun, it was that everything was annoying and frustrating and no fun at all.  I couldn’t enter a state of flow or concentration or even relaxing for any length of time.  Except when I played video games or the piano.  Neither were fun, exactly, and I was still in pain, but they were at least distracting and rewarding.  Looking back, this explains a lot of my behavior when I was in constant pain last year, it just took being out of pain and then very sharply in a lot of pain to make the pattern obvious.

At first I thought this was  Harrison Bergeron type thing, where pain was sending out interrupts too often for me to get into a groove on anything.  But then I read this blog post (blogs were just about in my power) by Sara Constantin on dopamine, explaining Peter Redgrave’s hypothesis that the spike (phasic increase) of dopamine is not itself a reward (which is how pop journalism usually describes it) but a timestamp that lets you know what actions should get credit for the actual reward chemicals you are about to receive.  That would explain why humans and animals with broken dopamine systems do feel pleasure when eating but will nonetheless starve to death unless you put the food directly in their mouth.

Many of the drugs used to treat ADHD inhibit dopamine reuptake, which raises your tonic (baseline) dopamine levels.  Constantin hypothesizes that if the baseline is too low than stimuli that should be ignored suddenly are interpreted as important, leading to a lot of SQUIRREL.

[ I was going to make this a gif but putting unpausable moving pictures in a post on ADHD just seemed cruel]

If this is correct, it offers an explanation for why ADHDers are so drawn to things like videogames and sex:  the time gap between doing the correct thing and getting the chemical reward is so short they can still determine causality, even against the a background of SQUIRRELs.  This needn’t be purely about hedonism- if it was, something consistently pleasant would work.  I think it’s about having an internal locus of control and self-efficancy.  Humans are happiest they feel like they have the power to change their own circumstances and have an impact on the world.  It’s hard to feel those things if your attention is constantly being torn away from what you choose and you can’t (on a neural level) determine what made you feel the emotion you are currently feeling.  This is one reason the toll of ADHD shouldn’t be measured in lost productivity alone; even people with very successful coping mechanisms are being denied that internal locus of control, and that’s miserable.

Here’s my contribution: my description of being in pain sounds a lot like other people’s description of ADHD, right down to video games being rewarding without strictly being fun.  And as it turns out the basal ganglion, the area Redgrave believes is using dopamine to timestamp causes so they can be matched with effects, also releases dopamine in response to pain.  It seems entirely possible to me that high baseline levels of dopamine could diminish the effect of a spike.  Instead of everything being timestamped “good job”, nothing is, with similar results

But let’s make it even more interesting.  Several anti-depressants are also useful in treating chronic pain, and NSAIDS (usually mild pain killers) treat depression.  I had previously put this down to “pain is depressing”, “depression appears to be connected to inflammation in ways we don’t understand” and plain old “brains are squishy and they don’t make sense”, but if there was a causal link?  The symptoms of depression include fatigue, feelings of helplessness and lost of interest or enjoyment of previously liked activities, which sure sounds related.  Quick googling found a very tiny study showing a connection between low dopamine and suicide, and this fascinating study suggesting that inflammation reduced the basal ganglia’s production of dopamine, which would tie all of this up in a very pretty bow.  Something causes pain and/or inflammation (the two often go together), which long term causes inflammation in the basal ganglia, which causes depression and reduces your body’s natural analgesics.

Look body, if you were worried about us getting high off of pain, maybe you could have releases fewer happy chemicals in response to pain, instead of making it just as fun but also cause depression some time later.

This would also explain why ADHD medicines are promising in treating depression (source, source, and a large showing among my friends), and why ADHD and depression so often go together.*

I cannot stress enough how unqualified I am to make this hypothesis.  Lots of people know lots more on all of these things than me.  But it comes together to be an extremely plausible explanation for both the literature I’ve read and my personal experiences.

*There’s a lot of evidence that depressed parents correlate with ADHD kids, but it’s probably environmental.