Bone mineral in mentally retarded patients receiving long-term anticonvulsive therapy

A direct photon absorptiometry method was used to measure bone mineral content in a population of mentally retarded subjects, one half of whom were undergoing long-term anticonvulsant drug therapy. The sample consisted of 134 subjects, 60 males and 74 females. Average ages were 22.5 years for the females and 19.7 years for the males. A multiple regression analysis showed there was no apparent effect on anticonvulsant drug therapy on bone mineral content in this mentally retarded and growth retarded population. A comparison with normal standards indicates that bone mineral values for age for both sexes of mentally retarded subjects were depressed from 15-40 percent relative to white standards. The bone mineral depression closely paralleled the growth depression seen in this population. It is suggested that the inability to detect an overall anticonvulsive drug effect on bone mineral values may be due to the general growth retardation seen in this institutionalized mentally retarded population.