Most psychologists would fall under the secondary category of care.
Primary category would include GPs (general practitioners), who are doctors that refer you to other specialized doctors in the secondary category if there is need for that. Secondary category includes specialized doctors such as dentists, psychiatrists, psychologists, etc. Tertiary category includes even more specialized doctors such as cardiologists, plastic surgeons, neuro surgeons, etc. And finally, quaternary category has to do with uncommon procedures that aren't widely accessible.