Psychologists are a PhD and many years of advanced, studies and one-on-one therapies. A lot of their work can be done in research. They also do clinical work and therapy.

Psychiatrists are Physicians within MD, and go through medical school the same was a surgeon or general practitioner like your family doctor does. They have less familiarity with some of the advanced statistical research, and often and spend less time doing one-on-one therapy with patients. Their main area of focus is integrating pharmaceutical and therapies together along with various life changes and other parts of whatever treatment plan a patient is on in order to fix their medical issues, such as addiction, dementia, Parkinson's, psychosis, depression, whatever. Methods are more invasive and I have more side effects but for more serious conditions are the only ones will be more effective.

The one big difference between psychologists and psychiatrists is psychiatrists have normal prescribing powers do you think I'm being fully licensed Physician. In a few jurisdictions, psychologist may be allowed to prescribe a few select medications. which medications and whether they're able to prescribe it all will vary significantly from place to place.

In countries with public Health Care, like Canada where Dr. Peterson is from, psychiatrists would be covered by government health insurance but psychologists usually are not.