can psychoactive substance treatment effects be adjusted quantitatively?

[CrawlingPossum]

Drug descriptions, e.g. for prozac, adderall, cocaine etc, talk about how the substance increases the level of some substances in the brain. Let's say adderall and cocaine, I think, increase levels of dopamine. Presumably this has good sides to it, but let's say in the case of big cocaine doses apparently it's bad what with loss of receptors etc. Well, so I was wondering, is it possible to implement a drug treatment based on actual measured dopamine level in the brain so that the dopamine level is increased to where we want it to be (presumably some sort of "healthy" level observed in "normal" people) but no further?

 

Well, and I guess a simpler question would be, can we even actually measure these dopamine levels in the first place for cheap? For that matter, how do we even know what happens to dopamine levels from this or that treatment? How is this stuff measured?

[iNow]

I think there's a basic flaw in your premise. Levels of neurotransmitters (like dopamine) fluctuation throughout the day, and depend greatly on what we're doing. There is no "one level," since the transmitters are responsive to what's happening in our environment. They could be very high, they could be very low... it really just depends.

 

Now, sometimes there are people who have chronically low levels of NTs like dopamine, but they too will fluctuate throughout the day. I'm sure there's a range of some sort which is considered normal, but it will vary greatly from person to person, and also within the same person depending on what they are doing.

 

As for testing levels of NTs in the system, there are many tests, often it's just a simple urine test.

[GDG]

Drug descriptions, e.g. for prozac, adderall, cocaine etc, talk about how the substance increases the level of some substances in the brain. Let's say adderall and cocaine, I think, increase levels of dopamine. Presumably this has good sides to it, but let's say in the case of big cocaine doses apparently it's bad what with loss of receptors etc. Well, so I was wondering, is it possible to implement a drug treatment based on actual measured dopamine level in the brain so that the dopamine level is increased to where we want it to be (presumably some sort of "healthy" level observed in "normal" people) but no further?

 

Well, and I guess a simpler question would be, can we even actually measure these dopamine levels in the first place for cheap? For that matter, how do we even know what happens to dopamine levels from this or that treatment? How is this stuff measured?

 

If you want to measure dopamine (DA) concentration directly in the brain, that's going to be pretty invasive: IIRC, DA neurons are burried under everything else in the brain. I think you can infer concentrations from blood levels, knowing the partition function between CSF and plasma. Most of what we know is based on animal experiments, where it is not unacceptable to insert a probe into the subject's brain and measure concentrations.