Disturbed Personality and Psychosocial Adjustment in Myotonic Dystrophy: Relationship to Intellectual/Cognitive Function and Underlying Affective Disorder (Depression)

Abstract

Recent investigations of cognitive and behavioral function in myotonic dystrophy appear to counter a number of the prevailing notions regarding this disorder. Myotonic dystrophy is characterized neither by intellect outside the range of normal (except in those infrequent cases of neonatal myotonic dystrophy) nor by intellectual deterioration. Apparent cognitive deficits more likely result from reversible neuroamine dysfunction associated with a biological depressive illness that may be an intrinsic part of the disorder of myotonic dystrophy. Much of the purported emotional problems, “personality disturbances and social deterioration”, represent symptomatology of this biological depressive illness. This depressive component seems to be responsive to tricyclic antidepressant treatment; such pharmacotherapy also provides additional benefit to other symptoms including gastrointestinal dysfunction, hypersomnia, myotonia, and muscular weakness. It seems probable that the basic genetic defect (possibly involving membrane structure) in myotonic dystrophy results in abnormal aminergic and peptidergic receptors and that dysfunction of the limbic system of the brain is only one of many disturbances caused by the receptor abnormalities.