Chronobiology in mental retardation research: progress and prospects

The premise of this review is that chronobiology, the science of biologic time structure and rhythms, is important in investigations concerning the etiology, mechanisms and effects of deficient mental adaptive development. Chronobiology is also shown to have potential importance in therapeutics and rehabilitation. Most of the information available now and supporting this wide-spread relevance of chronobiology relates to circadian rhythms, but physiological and behavioral rhythms having other cycle lengths also contribute. Recent findings in seven topic areas of chronobiology are reviewed with emphasis on facts and relationships actually or potentially important for consideration in mental retardation research. These are: 1) development of sleep and EEG patterns; 2) rhythmic susceptibility to seizures; 3) adrenocortical and dependent rhythms; 4) circadian rhythms in amino acids and biogenic amines; 5) rhythmic behaviors; 6) circadian rhythms in susceptibility and responses to drugs; and 7) circadian rhythms in human perception and performance.