Posted by linkadge on August 28, 2006, at 16:11:11
In reply to Re: Dopaminergic-based pharmacotherapies for Depre, posted by jealibeanz on August 27, 2006, at 18:02:37
>Your right in saying that dopamine increases >when one engages in addictive behaviors, but a >drug that increases dopamine in the brain does >not lead to such actions.
Its all about the area of the brain. Dopamine too isn't the magic pleasure chemical. The pleasurable effects of cocaine for instance are dependant on serotonergic and dopaminergic mechanisms.
The problem with dopamine is that it turns on "wanting" circutry. Illegal drugs like amphetamines can make you feel good in some ways but they don't leave you satisfied, you just want more. Its not really about the level of the chemical since the brain experiences pleasure in gradients. It will adapt to a higher level of the substance to try and maintain normal hedonic capacity.
You can increase dopamine in non-reward areas of the brain to try and increase motivation etc.
>If anything, it would prevent one with >deficient dopamine from seeking out such risky >behaviors to get a "high" from, since their
>brain chemicals are already being enhanced.Perhaps. Pretty much anybody can become addicted to illegal drugs. I don't thing it depends a whole lot on baseline neurotransmitter levels.
When it comes to neucleus accumbens activation, more is better. Thats why if you give mice one illegal drug, they'll still self inject other illegal drugs, the more the better.
>People taking stimulants or dopaminergenic >medications, such as Wellbutrin, don't >demonstrate a higher prevelance of addiction.In terms of wellbutin its hard to say since it isn't a very strong inhibitor of dopamine uptake. A high dose might only give you 20-30% inhibition of dopamine uptake. Its antidepressant effects are through other mechanisms.
As far as stimulants, the jury is still not out. Some doctors argue that taking stimulants early in life predisposes a person to crave stimulants later in life. We do know that people with ADHD are more likely to abuse other substances but it is hard to say if its the disorder or the treatmetns which lead to addictive behaviors.
Linkadge
poster:linkadge
thread:680536
URL: http://www.dr-bob.org/babble/20060825/msgs/680893.html