A neuropsychiatrist is a psychiatrist who specializes in the evaluation, diagnosis, and management of disorders at the brain-behavior interface, including:
- unexplained or functional neurological symptoms
- emotional, behavioral, perceptual, and cognitive symptoms that can occur in neurological diseases, including brain injury, stroke, dementia, epilepsy, multiple sclerosis, and other autoimmune diseases
- delirium and dementia
- neurobehavioral symptoms related to specific brain lesions
The latter two typically come under the field of "cognitive/behavioral neurology" which is subsumed under neuropsychiatry, though came out of neurology.
Neuropsychiatrists conduct a detailed psychiatric evaluation like their general psychiatry counterparts, but with particular emphasis on developmental insults, occupational and toxic exposures, family history, and medical/neurological history. The neuropsychiatric evaluation may include a full neurological examination, but tends to focus on the neurobehavioral mental status examination which focuses on the evaluation of higher cortical functions. Neuropsychiatrists routinely use neuropsychological testing, neuroimaging (MRI, FDG-PET, amyloid PET etc), neurophysiological testing (EEG, sleep studies), and laboratory studies (e.g. CSF studies such as antineuronal antibodies, QT-Quik, tau/phospho-tau/abeta42 etc) as part of their workup.
A forensic neuropsychiatrist is a neuropsychiatrist who uses their expertise to answer psycholegal questions. Forensic neuropsychiatrists conduct independent medical examinations in civil and criminal cases. These cases involve TBI, functional neurological symptoms, dementia (including bvFTD), and amnesia. Malingering of neuropsychiatric symptoms is extremely common in civil cases, and the forensic expert will perform symptom validity testing (or work with a neuropsychologist) to evaluate this possibility. The American Neuropsychiatric Association has a special interest group in this area, and the American Academy of Psychiatry and the Law has a forensic neuropsychiatry committee. Increasingly, neuroimaging features in the courtroom and forensics neuropsychiatrists may be called on to testify as to the relevance of this often used and abused modality. Of note, the neurologist Helen Mayberg, who is best known for her neuroimaging and DBS research in depression, actually makes her fortune as a plaintiff expert in death penalty cases regarding functional neuroimaging that has been presented in mitigation by the defense.