From Wikipedia: In the U.S., licensed psychologists hold a doctorate in their field, while licensed psychiatrists hold a medical degree with a specialty in psychiatry. Psychiatrists are physicians who have earned an MD or a DO, whereas psychologists have earned a PhD, PsyD, or EdD. Psychiatrists generally spend shorter periods of contact time with clients/patients, and the principal method of treatment is psychopharmacology. Conversely, clinical psychologists generally rely upon psychological assessment and the use of psychotherapy to relieve psychological distress. It is not uncommon for people suffering from mental illness to combine these services to maximize their impact.

A psychologist has a liberal arts degree. They are more research oriented. Studies to obtain knowledge of correlations is the foundation of the conclusions they make. They can have a specialization in counseling. The education is a bachelor’s degree with at least 5 courses in psychology (a minimum of a minor) and a graduate degree. A Doctorate in psychology requires participation in research and to be published in addition to the higher level of education. A Master’s may require that a thesis be written and defended after completion of coursework. Both require practicum and fellowship.

Both fields counsel from behavioral, cognitive and psychodynamic perspectives.

Individuals with Master’s will many times become certified in specific areas. Again, they cannot prescribe medication and take an approach more focused on counseling.

A psychiatrist has medical training followed by specialised training in psychiatry.

Both professionals can work with people with mental health problems but psychiatrists have the power to prescribe medicines whereas psychologists do not (in the UK anyway). Psychologists (clinical, counselling etc) use therapeutic approaches involving language, not drugs.

Some psychiatrists use talking therapies as well.

Otherwise they are essentially the same.