organic brain syndrome organic brain syndrome organic brain syndrome, also known as organic brain disease, organic brain disorder, organic mental syndrome, or organic mental disorder, refers to any syndrome or disorder of mental function whose cause is alleged to be known as organic (physiologic) rather than purely of the mind. these names are older and nearly obsolete general terms from psychiatry, referring to many physical disorders that cause impaired mental function. they are meant to exclude psychiatric disorders (mental disorders). originally, the term was created to distinguish physical (termed "organic") causes of mental impairment from psychiatric (termed "functional") disorders, but during the era when this distinction was drawn, not enough was known about brain science (including neuroscience, cognitive science, neuropsychology, and mind-brain correlation) for this cause-based classification to be more than educated guesswork labeled with misplaced certainty, which is why it has been deemphasized in current medicine. while mental or behavioural abnormalities related to the dysfunction can be permanent, treating the disease early may prevent permanent damage in addition to fully restoring mental functions. an organic cause to brain dysfunction is suspected when there is no indication of a clearly defined psychiatric or "inorganic" cause, such as a mood disorder. organic brain syndromeother namesorganic brain diseaseorganic brain disorderorganic mental syndromeorganic mental disorderencephalopathy as a result of head trauma,possible cause of organic brain syndromespecialtypsychiatry, neurologysymptomsdepends on the cause,usually memory problems, personality changes, mood swings, cognitive impairment, vision and movement problemsusual onsetover 60 years oldcausesorgan damage,generally of the brainrisk factorshead trauma, intoxication with certain substances, infection, vitamin deficiencydifferential diagnosisschizophrenia, bipolar disorder, post concussion syndrome, drug withdrawal part of a series onpsychology outline history subfields basic types abnormal behavioral behavioral genetics biological cognitive/cognitivism comparative cross-cultural cultural developmental differential evolutionary experimental mathematical neuropsychology personality positive psychodynamic psychometrics quantitative social applied psychology applied behavior analysis clinical community consumer counseling critical educational environmental ergonomics food forensic health humanistic industrial and organizational legal medical military music occupational health political psychometrics religion school sport traffic lists disciplines organizations psychologists psychotherapies research methods theories timeline topics psychology portal types organic brain syndrome can be divided into 2 major subgroups: acute (delirium or acute confusional state) and chronic (dementia). a third entity, encephalopathy (amnestic), denotes a gray zone between delirium and dementia. the diagnostic and statistical manual of mental disorders has broken up the diagnoses that once fell under the diagnostic category organic mental disorder into three categories: delirium, dementia, and amnestic. delirium