Which of the following mental health professionals is most likely to have either a PhD or a PsyD and diagnose and treat mental health problems ranging from the everyday to the chronic and severe?

A) clinical psychologist
B) research psychologist
C) psychiatrist
D) counseling psychologist

Answer: A
Rationale: Clinical psychologists are mental health professionals with doctoral degrees (PhD or PsyD), who diagnose and treat mental health problems ranging from the everyday to the chronic and severe. In contrast, psychiatrists have medical degrees (MD), and counseling psychologists typically work with people needing help with common problems such as stress, coping, and mild forms of anxiety and depression, rather than severe mental disorders.