Quick summary: My intention is to give you a horribly over-simplified definition of all those terms that you may find when you are looking for a mental health worker. I will give you an easy to understand definition of what the difference is between a Psychologist, Psychotherapist, Psychiatrist, Social Worker etc… I must add this disclosure up front – there is no strict definition nor is there any way to accurately state the specific functions of any of these mental health care workers. The specific abilities or specialties of any mental health worker vary greatly depending on their: personality, school they went to, age, education outside of college etc…