It is the branch of medicine focused on the diagnosis, treatment, & prevention of mental, emotional, & behavioral disorders. People seek help for many reasons such as panic attacks, thoughts of suicide, hearing "voices", feelings of sadness, & hopelessness causing everyday life to feel distorted.
A psychologist is a trained mental health professional who helps people learn healthy ways to handle mental health challenges. Psychologists study and help treat people’s cognitive, emotional, and social processes and behaviors.