MIND, BRAIN AND BIOCHEMISTRY 397 



gonadal effect. Nevertheless the great influence of various 

 hormones on human behavior cannot be overlooked. Adminis- 

 tration of thyroxin to a hypothyroid individual can convert 

 a sluggish, perpetually tired individual to a bright, active 

 person. Out of such observations has grown the entirely new 

 field of psychoendocrinology.-^ 



Biochemical Disturbances and Abnormal Behavior 



In classifying biochemical disturbances and abnormal be- 

 havior, it is best to begin with the class of congenital mental 

 deficiencies which result from what is frequently called a 

 " metabolic error." In its essential form this concept was first 

 proposed by Sir Archibald Garrod when he suggested that 

 certain diseases, e. g., alkaptonuria and albinism, could be 

 explained by the absence of certain specific enzymes.'" How- 

 ever, it has not yet been directly established that a particular 

 enzyme is absent. All that one can conclude is that the enzyme 

 in question is not junctioning properly. The failure of an 

 enzyme to function normally can be due to at least one of 

 several causes: (1) the enzyme may truly be absent, (2) it 

 may have a relatively slight structural abnormality, or (3) 

 though normal, it may not be able to function because of some 

 obstructive alteration in the cell or organism.-^ Furthermore, 

 in some instances the enzyme defect can be further traced to 

 the apparent absence or failure of a particular gene.^* The 

 resulting condition can involve a variety of physiological dis- 

 turbances, some of greater consequence than others. In some 

 cases the full development of the illness can be forestalled by 

 eliminating from the diet those substances which cannot be 

 metabolized because of the enzyme defect. 



^^ M. Reiss, " Psychoendocrinology," in M. Reiss, ed., Psychoendocrinology (New 

 York: Grune & Stratton, 1958) , pp. 1-40. 



^^ D. Y-y. Hsia, Inborn Errors of Metabolism (Chicago: Year Book, 1959), p. 105. 



" Ibid. 



-* R. W. Lippman, T. L. Perry and S. W. Wright, " The Biochemical Basis of 

 Mental Dysfunction. II: Mental Deficiency (Amentia)," Metabolism, VII (1958), 

 274. Cf. L. S. Penrose, The Biology of Mental Defect (New York: Grune and 

 Stratton, 1949). 



