For me, the OTC supplement 5-HTP has proved a more effective therapy for my non-motor symptoms than levadopa has been for my motor symptoms.
What is 5-HTP?
It's basically a serotonin booster. Serotonin is one of the neurotransmitters that light up the brain. It is allied with another neurotransmitter, dopamine. Parkinson's results from the depletion of dopamine-generating cells in the brain.
Dopamine regulates muscle movement, motivation and reward seeking, sociability, and pain processing. Serotonin primarily affects mood, impulsiveness, appetite, intestinal motility, sex drive, and the sleep/awake cycle.
5-HTP and me
Here’s a quick rundown on PD's major non-motor symptoms, and my experience with 5-HTP as a therapy for them.
Symptom 1) Depression
Depression returned with the arrival of Parkinson’s. When it did, I almost sold my house and moved into a senior residence. The neurologist who diagnosed the Parkinson’s prescribed Elavil for the depression. Then, my present neurologist expressed concern about that drug's possible adverse effect on cognition. I told him about my earlier, positive experience with 5-HTP. He approved my suggestion that I try it again, and I've been depression-free for four and a half years now.
Symptom 2) Insomnia
Thanks to 5-HTP, I’m now insomnia free for the first time in my life. For nearly five years now, I log at least seven hours of sleep each night. I can easily get back to sleep after my 3-4am hour of meditation and exercise. This quality of sleep is the best I’ve ever had.
Symptom 3) Constipation
Symptom 4) Cognition and Executive Function
That function includes decision making, problem solving, and planning. Parkinson’s impact on executive function was a key theme in Michael Kinsley's article in The New Yorker last month, which I discussed in a blog post.
This is where it gets weird: Instead of experiencing problems with executive function, I’m encountering just the opposite. It's clear to me that 5-HTP is the reason.
I take my 5-HTP pill at bedtime. More often than not, when I open my eyes in the morning, my first thought brings a solution to some problem that had been bothering me. My middle-of-the-night “quiet hour” also produces those solutions, or creative new ideas.
When I increase my nighttime 5-HTP dose, even a little, the next morning can bring ideas -- some crazy -- that explode like fireworks on the Fourth of July. With those ideas comes a euphoric mood that borders on mania. I admit; it's very pleasant. Unfortunately, those mornings are usually accompanied by big spikes in my blood pressure.
A New Development
What the hell is going on?
Here's my theory: As Parkinson’s destroys my dopamine-producing cells, using 5-HTP to boost my serotonin offsets the damage, particularly with respect to non-motor functions. My five years of experience with PD and 5-HTP makes this theory seem credible to me.
- Most of us with PD take levadopa, designed to replace the dopamine our disease destroys. But the levadopa is mixed with carbidopa, since that addition helps the levadopa pass the blood-brain barrier. As it turns out, carbidopa works the same way with serotonin, helping it enter the brain where it can have an impact. So when we take 5-HTP when we're already taking carbidopa, the positive effects (on issues like mood and insomnia, for example) are enhanced.
A 2011 NIH study concluded that serotonin plays a significant role in the brain's executive function. So carbidopa-enhanced 5-HTP could be kick-starting my executive function.
- A 2012 article in Scientific American reported on the use of stem cell grafts on patients with PD. Those grafts, when they "took" properly, helped restore dopamine function. As a result, patients scored very well on all measures of motor function. But those same patients -- with normal dopamine levels -- had serotonin levels even lower than untreated patients, and were having issues with bowel and sexual function, mood, and sleep -- all problems linked to serotonin. The authors proposed multiple grafts of dopamine and serotonin cells. But then, significantly, they suggested that for those with less severe PD symptoms, it might be enough to combine levodopa with "something else to increase serotonin function while possible."