Why do docs don't want the law to allow psychologists to prescribe meds?

No medical education: This is controversial, as psychologists in some states are legally able to prescribe psychiatric medications after a course in psychopharmacology. This is not the same as having the depth and breadth of 4 years of medical education, or serving a 4 year psychiatric medicine residency (which includes general medicine rotations). Treating with meds is much more involved than writing scrips alone.

See below: Far more to writing a script than meets the eye: besides pharmacology, a doc must have thorough understanding of bio-chemistry & human physiology to know how meds work & all the systems they may affect (even if not wanted). There are also many medical conditions that can present with psychologic symptoms; not having adequate training in those areas limits their understanding of pt as whole being.