That any somatic disease may influence any mental disease favorably is a matter of great theoretical and practical importance. The malarial treatment of paresis is a concrete example of its clinical utilization.1 But its theoretical implications extend far into the complicated questions of the interrelations of psychic and somatic disease and touch intimately on the important problem of reversibility.
That it is a fact of repeated observation that somatic disease may favorably affect preexisting psychotic manifestations should not require much evidence here. Pinel2 enumerates various disorders "operating to produce a permanency of recovery." Jacobi3 mentioned it in 1844. Koster4 wrote an inaugural dissertation on it in 1848 at Bonn; and the literature contains fully two score contributions, case reports and discussions. Back of all this, of course, is the theory, presumably based on many observations, of traumatic or shock treatment.
But the precise delimitation of the