Health psychology is the study of psychological and behavioral processes in health, illness, and healthcare. It is concerned with understanding how psychological, behavioral, and cultural factors contribute to physical health and illness. Psychological factors can affect health directly.
Clinical psychology is a broad branch of psychology that focuses on diagnosing and treating mental, emotional, and behavioral disorders. Some of the more common disorders that might be treated include learning disabilities, substance abuse, depression, anxiety, and eating disorders.
Behavioral neuroscience, also known as biological psychology, biopsychology, or psychobiology is the application of the principles of biology to the study of physiological, genetic, and developmental mechanisms of behavior in humans and other animals.