Neuropsychology is a specialty field within clinical psychology that aims to understand how behavior, emotion and cognition are influenced by brain functioning. Neuropsychology focuses on the behavioral and cognitive assessment and treatment of patients with brain injury, disease, or severe mental illness, such as bipolar disorder.

In a neuropsychological assessment, brain functioning is evaluated by objectively testing cognitive skills using numerous standardized and validated tests. Test performances are then compared to reference groups of the same age, gender, race, and educational attainment. This normative comparison helps neuropsychologists determine if individuals are performing within expectations, and provides information about cognitive strengths and weaknesses which aid in diagnosis or inform treatment planning. Performances can be compared to others with and without the illness. 

In the Prechter Longitudinal Study of Bipolar Disorder, neuropsychology testing provides information about different areas and systems of the brain and how they are impacted by illness, medications, and environmental factors. Test performances can be used to predict functionality, treatment response, and illness recovery. With repeated testing, we can also follow the natural course of cognitive abilities over time in individuals with bipolar disorder.

Several cognitive areas are measured using standardized clinical and experimental neuropsychological tests:

■ General intellect
■ Motor skills
■ Attention and concentration
■ Higher-level executive skills (e.g., reasoning, problem solving)
■ Learning and memory
■ Emotional processing skills

Brain functioning can also be measured through electrophysiology, where we measure the levels of electrical activity across the scalp of research participants using electroencephalograms (EEG), while they perform certain cognitive tasks. The goal is to identify electrophysiological markers that can be used for diagnosing or monitoring disease process or treatments. For example, we have shown that the size of certain brain waves differs in individuals with bipolar disorder who have attempted suicide and those who have not. The difference in amplitude of these waves may represent differences in levels of impulse control.