This is a possibility. If this is our assumption, then we must ask, "Why is there no dopamine?" There are several possibilities.:

a) No dopamine was transported to the transfer point.

b) No Dopamine was created.


If we assume that no dopamine was transported to the transfer point, again several ssibilities arise as to why.

1) The transport mechanism(s) are malfunctioning.

2) There was no dopamine available for transport

3) The transport of dopamine was blocked or hindered.



Am I missing anything yet?

Now the "How" questions need to be addressed as well.