184 DISEASES DUE TO MALADJUSTxMENT 



Over- Activity of the Thyroid. — The reverse change 

 in the thyroid may also take place and excessive amounts 

 of secretion be produced. When this happens the general 

 level of basic metabolism is raised, the symptoms ex- 

 hibited being those resulting from increased metabolism. 

 Increased food supplies are naturally required to carry 

 on the heightened metabolism and sufferers from this con- 

 dition are invariably exceptionally hearty eaters, not- 

 withstanding which they are usually emaciated. The 

 increased metabolism of the nerve-cells has, as would be 

 expected, the contrary effect to the lowering of metab- 

 olism, the nervous processes are speeded up. Unfortu- 

 nately, this does not bring about, as one might expect, 

 a corresponding improvement in intellectual power. On 

 the contrary, the result is a rather marked irritability, 

 together with a tendency to instability of disposition 

 which in severe cases amounts to mental derangement. 

 It is evident that efficient nervous functioning requires 

 that the basic metabolism of the nerve-cells be pitched on 

 neither too low nor too high a scale. The quality of opera- 

 tion of the nervous mechanism is not determined by the 

 rate at which it works but by the underlying degree of 

 excellence of the apparatus itself. 



Pituitary Gland Impairment. — There is a disease 

 from which adult human beings sometimes suffer, in 

 which various bones resume growth after having attained 

 the normal adult condition. One bone that is commonly 

 affected is the lower jaw. The patient first becomes 

 aware that something is wrong by observing that his 

 teeth no longer meet, that his lower jaw has grown to an 

 extent sufficient to throw the lower teeth out of align- 

 mout with those of the upper jaw. The bones of the ex- 

 tremities may also resume growth, enlarged knuckle- 

 joints and enlarged finger- and toe- joints being a result. 

 Study of this disease shows that it is due to an increase 

 in the activity of the pituitary body. 



Diabetes. — This disease, which results from deficiency 



