How can lack of Serotonin have anything to do with OCD?

Question

I get it it’s the good mood hormone and you can feel down when you are low on it. Makes sense how it could be the cause of depression.

But how it can be related to brain making stressful thoughts? And forcing one to do compulsions for relief?

And why when you take SSRIs and your Serotonins reach a normal level, a significant reduction of symptoms occurs? I don’t get it.

In: Other

Answer 1

Serotonin and your other neurotransmitters can be thought of like muscles – your body uses them to do many different things. If the muscle is in your arm, then it moves your arm. But, if it’s in your leg, it moves your leg. The neurons using serotonin are what determines what happens in each case. 

Using dopamine as an example: a lot of people think of dopamine as the “happy chemical”, and yes, the neurons that tell your brain “we like that, do more of that” do use dopamine to talk to each other. But other neurons use dopamine for other stuff too. Over in a different part of your brain, a group of neurons that help you move also use dopamine to talk to each other, which is why Parkinson’s drugs up the amount of dopamine in your brain.

So, we know that neurotransmitters are tools your cells use to talk to each other, but don’t tell us what’s being talked about. And we know that giving people with OCD drugs that up serotonin helps them because we can see them getting better after we give them some. The rest is still an area of active study! 🙂  There are some good ideas out there, but the question “how can upping serotonin remove obsessive thoughts and compulsions” isn’t fully settled! Some people think an area called the CBGTC loop is the reason why because it seems to affect mental control (breaks in ADHD, OCD, and Tourettes) and movement (breaks in Parkinson’s and Huntington’s).

As to why symptoms go away when serotonin levels change – when you don’t have enough serotonin in one part of your brain, all the parts that talk to the broken part get confused. They’re not broken, but they get bad information, so they do weird stuff. Like taking away a muscle in your arm – the whole movement of your arm goes wonky. It might still do most things an arm does – reach for things, control the fingers on your hand (those muscles are in your forearm!) – but maybe it does those in a weird way. When serotonin levels are corrected, all the weirdness goes away and the system works together again.