Students must obtain a master's and a doctoral degree to practice as a clinical psychologist. Students with a bachelor's degree in psychology can assist psychologists or work in the mental health profession, however their opportunities are more limited. There are two types of doctoral degrees – a Ph.D. (Doctor of Philosophy) and a Psy.D. (Doctor of Psychology). Psychologists with a Ph.D. generally qualify for a number of teaching, research, clinical or counseling positions, while those with a Psy.D. often work in clinical positions. At least 2 years of study are required to earn a master's degree in psychology, while 5 to 7 years of graduate study are needed for a doctoral degree. Upon earning an advanced degree from an accredited school, students must meet proper certification requirements which may include completing an internship and passing an examination.