18. January 2010 06:45
<< Dopamine replacement therapy causes brain dysfunction in patients with Parkinson disease, study says |


New research unravels the brain mechanisms that underlie the ability of a standard drug treatment for Parkinson's to elicit compulsive behaviors in some patients with the disease. The study, published by Cell Press in the January 14th issue of the journal Neuron, provides fascinating new insight into the brain mechanisms that underlie a predisposition to behavioral addictions, such as pathological gambling and shopping.

http://www.news-medical.net/news/201...-patients.aspx

i don't get this.

Paula - it is confusing! this is how I interpret it:

the paper says, "The researchers observed that dopamine agonists elicited an increase in the rate of learning from beneficial outcomes"

While this sounds like a good thing, in our case it is not. Because it means that "The mechanism may also explain why anecdotally some patients describe the onset of their gambling symptoms after experiencing a 'win'."

In other words, our gambling compulsion is triggered by just one experience of winning; we had a "beneficial outcome," so we crave more.

Then the researchers also discovered "a greater prediction error, signifying a better than expected outcome, in susceptible individuals with Parkinson's disease."

This means that we don't predict well from our experience - we think we will continue to to get the beneficial outcome of winning, and are damaged in our ability to predict that this is not necessarily true.

I think the article is confusing because it uses positive words like "better than expected outcome" to describe damaging behavior.

At least that's what I think it is saying - it just reinforces what we already know.

Haha Carey thanks I needed that! Just when I think I get it, they say something positive that isn't good.....

I think I'd say I'm 100% sure that it could have been worded better.


What you said sounds good to me.
paula

Paula - it's all Greek to me!

I'm a little exhausted but wanted to chime in once more. Boann, I apologize for some of my previous tone - I am just so discouraged with having had awful experiences that my doctors didn't take seriously or dismissed, and I'm a little sensitive about that. Carey, I give fullest kudos to the good scientist who made this revelation to the world about DAWS, absolutely. She's a brave lady, and I'm just frustrated that the medical world could not have come to these conclusions on their own a long time ago. It's like they haven't even been seeing patients.

As for the discussion about "pre-dispositions" - that's so transparent as a way to shift blame off the drug makers, and it's such an intangible, unquantifiable value judgment as to be virtually useless. How does one test for predispositions?

Now about this learning from a positive outcome - so you gamble, and you win, and then that makes you want to try again??? How much research money did we spend to find that one out?

Peg, I hope those things are neuroprotective, too.

Now about this learning from a positive outcome -so you gamble, and you win, and then that makes you want to try again?? How much research money did we spend to find that one out?

i knew there was an easier way!

Fiona -

You said "Now about this learning from a positive outcome - so you gamble, and you win, and then that makes you want to try again??? How much research money did we spend to find that one out?"

The urge is much more than that; it can mean winning $100 at first, and then sitting there until you lose $100,000 or whatever amount of money you have access to. You can't stop - your judgment is damaged; your predictive error is high; you believe you can win again - a better than expected outcome.

It's one of those things that unless you have it, it's hard to understand. I think they are getting closer to being able to use imaging techniques to get a better understanding of the addict's brain. Before any of us "get" PD, our brains are wired differently at birth. Not everyone is wired for addiction; PD meds make the addiction that much worse.

Yeah, Carey, I know what you mean. I'm interested in the difference between addictive and compulsive, how those are different in the way they play out. But that's a whole other thread....

Here's one answer; there are lot's more if you google "difference between addiction and compulsion"

From Wiki Answers http://wiki.answers.com/Q/What_is_th...d_a_compulsion

Compulsion versus Addiction

A COMPULSION is based upon the psychological principles of dependency, need and desire. Although compulsive behavior may have physiological aspects attached to it such as feelings of satiation, and psychological withdrawal, compulsion does not alter the brain the way addiction does. Compulsive behavior that is secondary to an Obsessive-Compulsive Disorder is a neurobiologically acquired mental illness. ADDICTION on the other hand is a medical term that refers to a neurobiological process that in addition to compulsion, obsession, loss of control, and a continuation in spite of dangerous consequence, also must include as part of its definition, a progressive neuronal desensitization, and a brain-based neurochemical alteration.

A good example that helps distinguish these terms from one another is that of drug addiction and sexual addiction. Many individuals use drugs such as marijuana, cocaine, and/or alcohol on a recreational or social basis. These individuals are capable of stopping their ususage at any time with no lasting harmful physiological or cognitive consequence. Individuals addicted to a drug however, are not able to stop their behavior without significant brain-based physiological consequence such as seizures, gastroenterological disturbances, heart palpitations, changes in blood pressure, and cognitive disruptions in areas of memory, concentration, and decision-making. The same principles apply to a sexual compulsivity and a sexual addiction. With a sexual addiction, sexually ritualistic behaviors alter the neurochemistry of the brain not just during sex, but well before and well after the sexual act. Additionally, sexual addicts, just like drug addicts, experience a host of cognitive impairments generally specific to the executive functioning of the right prefrontal cortex such as decision-making, concentration, abstract thinking, attention, insight and judgment, conceptualization, and mental flexibility.

Reference: Ullman, S. (2006). A Neuropsychological Examination of Neural Plastic Alteration in the Dorsolateral and Orbital Prefrontal Functions Secondary to Early Childhood Sexual Traumatic Eposure in Diagnosed Adult Male Sexual Addicts. Ann Arbor, MI: Proquest.
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seems like a compulsion is more behavioral; and addiction is biological

And this is heavy stuff. We get the dx, freak out, accept, adapt, going ok, still going ok, but always the underlying stress of being chronically ill...and the more I try to speak, the more jumbled up I get. Now I 'm starting to look stupid - I'm not, I just look like I am, always new limitations....on and on.

so which is the most important part to save? Who is trying to save anyone? Who is doing what? Who can claim the name to new conditions? Are people who drag these agonist problems through the mud, years after the patient community has known about it, learned it the hard way. and spread the word- just learning about it? That's a scary thought.

So what for? Doth thy study hope to discover?

Now we are getting closer than ever to how our brain works and figuring out some pretty fascinating connections that include our behavior. I understand almost nothing, but have this visualization and the background info to follow transmitters until I smack into the wall like the animal in Ice Age....end of comprehension.

p