Melanin has many biological functions, including colouring the skin and hairs or feathers, strengthening plant cell walls and insect cuticle, absorbing light (and so providing photoreceptor shieldlng, thermoregulation, photoprotectlon), and it is an important free radical sink.
Medical Definition of autistic disorder. : autism Autistic disorder is classic autism, one of the more severe disorders on the spectrum. Persons with autistic disorder have substantial impairment in social skills, verbal communication, and cognitive and behavioral flexibility.âIsabelle Rapin , The New England Journal of Medicine, 1 Aug. 2002.
Related to mood disorder: personality disorder, cyclothymia. n. Any of a group of psychiatric disorders, including depression and bipolar disorder, characterized by a pervasive disturbance of mood. Also called affective disorder. Etymology: AS, mod, mind; L, dis + ordo, rank. a variety of conditions characterized by a disturbance in mood as the main feature.