Clinical psychology deals with the assessment of abnormal human behavior and its treatments. The common method of treatment for this type of abnormal behavior is talk therapy or psychotherapy which was first developed by psychoanalyst Sigmund Freud; he was the first to insist that mental illness can be treated by talking to patients.

Neurobiology is the branch of biology that deals with the functions and structures of the nervous system. Specifically, neurobiology focuses on cells and tissues of the nervous system and the ways in which they can form structures and circuits (pathways) to control the body.This system includes common structures, such as the brain and the spinal cord, and the nerves. Neurobiology can be classified as a sub-discipline within the larger field of physiology.

Neurogenetics studies the role of genetics in the development and function of the nervous system. The field of neurogenetics arose out of advances in molecular biology, genetics and the desire to understand the connection between genes, behavior, the brain, and neurological disorders and diseases.

Neurosurgery is a specialization that treats diseases and disorders of the brain and spinal cord. Back pain can sometimes produce neurological symptoms such as numbness, muscle weakness, due to poor coordination of the nerves. These symptoms indicate that neurosurgery is needed to treat conditions that cannot be treated with normal methods. Neurosurgery includes discectomy, laminectomy, and spinal fusion surgery. There is often a higher risk of nerve damage and infection that can lead to paralysis.

Behavioral genetics is the story of how a person's genetic makeup, the environment they are exposed to affects that person's behavior. Technological advancements in genetic engineering in the 21st century have made it possible to measure and modify a person's genome which is key to behavioral genetics and later to the eugenics movement.

Psychopedagogy deals with the behavior of a person during the learning process from a cognitive aspect. Educational psychology helps the teacher to understand the development of his students, the extent and the limits of their learning capacities.

Experimental psychology explores basic concepts, such as memory and motivation, in many areas, such as child, social and educational psychology. Almost all Experimental psychology work is conducted in controlled environments, such as university research labs. While every branch of psychology strives to understand human behavior and thought, experimental psychology solely focuses on controlled experiments with designated variables, test subjects and statistical results.

Neurological disorders are diseases of the central and peripheral nervous system. In other words, the brain, spinal cord, cranial nerves, peripheral nerves, nerve roots, autonomic nervous system, neuromuscular junction, and muscles. These disorders include epilepsy, Alzheimer's disease and other dementias, cerebrovascular disease including stroke, migraines and other headaches, multiple sclerosis, Parkinson's disease, neuroinfections, brain tumors, traumatic nervous system disorders due to head trauma and other neurological disorders as a result of malnutrition.

Cognitive neuroscience is the study of how the brain influences the mind. Cognitive science uses the experimental methods of cognitive psychology and artificial intelligence to create and test higher-level models of cognition such as thought and language. Cognitive neuroscience acts as a bridge between the brain and the method.

Applied behavior analysis is a type of treatment process that primarily focuses on improving a specific behavioral process. Unlike most therapies where they try to explain why and how the person behaves the way they do, applied behavior analysis attempts to replace bad with good; he uses positive reinforcement to make that change. This method of therapy is mainly applied to autistic patients.

Mental disorders (or psychological disorders) are conditions that affect your thinking, feelings, mood, and behavior. They can be occasional or long-lasting (chronic). They can affect your ability to communicate with others and to function every day. The causes of mental disorders are often not clear. Theories can incorporate findings in a range of areas. Mental disorders are generally defined by a combination of the way a person behaves feels, perceives or thinks.

Biological psychology is the only branch that says that there is an underlying physiological cause for all of our emotions, thoughts and feelings. For example, the release of oxytocin in women leads to binding behavior, etc.