Biological psychology may be looked at as a hybrid of neuroscience and psychology. Practioners of biological psychology may use their knowledge of the brain, from neurotransmitters to the cerebral cortex to treat their patients. Others may use this knowledge to search for biological causes for common mental illnesses, such as depression and schizophrenia.

Many psychologists focus largely on the mental processes of their patients. A biological psychologist realizes that there is an organic basis to all mental processes, that is there is no difference between the brain and the mind. They realize that treating the organic problem may be accomplished by talking as well as drugs. Eric Kandell is a great proponent of this theory.