A Neurobiological Brain Disorder (NBD), also referred to as a Neurobiological Disorder (NBD), is an illness caused by genetic, metabolic, endocrinological or other biological factors, that affects the functioning of the brain.
Many illnesses categorized as psychiatric disorders have a neurobiological basis and are sometimes referred to as "neuropsychiatric disorders".
Some illnesses considered to be neurobiological brain disorders are: Autistic-Spectrum Disorders, Schizophrenia, Tourette syndrome, Parkinson's disease with dementia, Obsessive-compulsive disorder (OCD), Alzheimer's disease, as well as some forms of Major Depressive Disorder (MDD), Anxiety, and Attention Deficit Hyperactivity Disorder (ADHD).
Many of the Neurobiological Brain Disorders that are currently co-classified as "psychiatric" or "mental-illness" are being found to have a high co-morbidity with endocrine-system abnormalities such as in the hypothalamic-pituitary-thyroid axis.
Historically, other illnesses with previously unexplained etyiologies, when affecting brain function such as thyroid hormone dysfunctions, Multiple Sclerosis, and certain vitamin deficiencies, had also been considered "psychiatric" until diagnostic tests were developed specific to those disorders.
Although some of these disorders in very young children are classified as developmental (such as Autism and Asperger syndrome) for insurance purposes and special educational services, others, such as pediatric-onset schizophrenia and bipolar disorder, are not globally accepted as such, resulting in a great discrepancy in educational and medical parity.
See also: Neuropsychiatry
More information on Neurobiological Brain Disorders:
National Institute of Mental Health (NIMH)
Clinical Brain Disorders Branch of the Departments of the National Institute of Mental Health (NIMH) and National Institutes of Health (NIH)
Endocrine Abnormalities and Psychiatric Manifestations:
Identifying hypothyroidism’s psychiatric presentations
Lingering Psychiatric Symptoms From Hyperthyroidism
Protein Biomarkers for Schizophrenia Studied in Cerebrospinal Fluid