Seroquel is an antipsychotic...so it works for blocking psychosis...probably mood stabilization but at low doses it's actually used for sleep unlike other APs....as such it tends to be more sedating than other APs...I'm not sure what depression symptoms you're getting but if they have to do with being tired and unmotivated then it's probably the med side effects. While zyprexa is among the worst APs for weight gain, seroquel is not far behind....if you want no weight gain your options are abilify, Geodon or Latuda....in that class of drugs.

As far as taking them together...they have the same primary mechanism so it would be like increasing the dose....however this is done in some cases of severe treatment resistant schizophrenia. I wouldn't recommend it for you though. Hope that helps...