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Go to CuriosityStream.com/SciShowPsych to start streaming thousands of  documentaries and nonfiction TV shows. [♪INTRO]. Your brain has a limited number of  molecules that let you do everything you do.

And in pop culture, we tend  to have a pretty narrow view of what each molecule regulates. Dopamine makes you happy, right? Well, it totally can.

But this  neurotransmitter can also help you move around, take appropriate risks, and focus! And  that is just the tip of the iceberg. So when you have different amounts of  dopamine in certain regions of your brain, it often affects you in more ways than one.

Dopamine is made in and sent to a  few different parts of the brain. It often gets sent to the caudate putamen, which is a part of the brain  involved in producing movement. So dopamine is an influential chemical  in diseases that affect movement, like Parkinson's Disease.

Parkinson’s is a neurodegenerative disease  that makes it difficult to initiate and control movement like walking or writing. So, many people diagnosed  with Parkinson’s experience a characteristic shaking symptom. And while dopamine is not  the only chemical involved, there isn’t as much of it in the brains  of people diagnosed with Parkinson’s.

This is likely because the  brain cells that release it progressively degenerate as the disease worsens. About half a million people in the US alone are diagnosed with this kind of  disorder. And today, there is no cure.

But there are some treatments  that some people find helpful, like the drug pramipexole. It is a drug that is designed to look like  dopamine and bind to dopamine receptors. Basically, it pretends to be dopamine.

This reduces the symptoms of movement  disorders like Parkinson’s disease and Restless Leg Syndrome. But dopamine doesn’t just  go to the caudate putamen. It also goes to the nucleus accumbens, which can impact depression  symptoms, among many other things.

A 2010 study published in Biological  Psychiatry found that some people with treatment-resistant  depression had symptom improvement after deep brain stimulation  to the nucleus accumbens. Depression is also a commonly  reported symptom of Parkinson’s. So these symptoms likely go hand in hand because they can both be the result  of low dopamine in the same person.

And it can be a good thing that  dopamine acts in both of these ways when we’re trying to treat multiple symptoms, because it means that pramipexole  could be a two-in-one treatment for motor symptoms and depression in Parkinson’s. Even if you don’t have Parkinson’s,  it can treat depression alone. Stimulating dopamine in your brain affects  a wide range of feelings and behaviors.

But that wide range also means this treatment  could take things in another direction. Increasing your dopamine  levels in the nucleus accumbens can send your risk-taking  tendencies into overdrive. For example, Parkinson’s medications  have been known to lead to side effects like being more  prone to compulsive gambling.

Motor control and risk-taking  are very different behaviors, but both are controlled by dopamine. So medications that regulate dopamine  levels could bring your motor control back to manageable levels but over-activate  your drive for seeking rewards. Manipulating dopamine with drugs  like pramipexole can lead to lots of other off-target, or unintended effects because dopamine can be found  pretty much everywhere in the brain.

Dopamine also goes to the prefrontal  cortex to impact attention, the hippocampus to impact memory, and the hypothalamus to impact hormone  secretion, and the list goes on. Some pharmaceuticals even  create Parkinson's-like symptoms in people who previously did  not have movement disorders. And unfortunately, we can’t deliver  a drug to just the part of the brain where the dopamine regulates movement.

The drug is systemically administered. So it goes to all parts of the brain and  acts wherever there are dopamine receptors. Whether these impacts are relatively good or bad often depends on the person and  their pre-existing brain chemistry.

So one neurotransmitter does not exclusively  make you just happy, mobile, or focused. The same one often does all of these  things in complex and interconnected ways! This episode is brought to you by CuriosityStream, a subscription streaming service that  offers thousands of documentaries and non­fiction TV shows from some  of the world's best filmmakers, including exclusive originals.

CuriosityStream has thousands  of streamable documentaries and non-fiction TV shows on topics  like History, Nature, Science, Food,. Technology, Travel, and more. Like, if you found this episode  interesting, you might enjoy learning more about the science of happiness with the  documentary “Curious

Minds: Happiness,” which talks about how genetics and  behaviors can impact happiness. And you can use the code SciShowPsych  to sign up for CuriosityStream for just $14.99 for the whole year. Thank you for watching this  episode of SciShow Psych! And thank you again to CuriosityStream  for sponsoring this episode. [♪OUTRO].