ve feeling of effort is the limit reached in true depression,
while it is merely the beginning of the intellectual disorder in stupor,
for one meets with retardation symptoms only in the partial stupors. The
slowing in these cases seems to represent an early stage of the
intellectual disturbance which reaches its acme in the mental vacuity
and complete incompetence of the deep stupor, just as slow movements in
the partial stupors seem to represent a diluted inactivity reaction.
This actual thinking disorder is not present in those forms of
manic-depressive insanity which are characterized by elation, anxiety or
depression but is seen only in stupors, occasionally in absorbed manic
states (manic stupor) and sometimes in perplexity states. The
psychological mechanisms of this last group are probably analogous to
those of stupor, but this is not the place for a discussion of this
topic.

Another associated symptom whose manifestations differ in depression and
stupor is that of unreality. In the former there is frequently a feeling
of unreality that is purely subjective, whereas the stupor case does not
usually complain of this but does exhibit a difficulty in grasping the
nature of his environment, which the typical depressive case never has.

The occurrence of other mood reactions than apathy in the same patient
is also characteristic. Manic states (usually hypomanic) frequently
occur during the phase of recovery from the stupor. This is an unusual,
although not unknown, phenomenon in recovery from severe retarded
depressions. The circular cases who swing from depression to elation
usually show the milder types of depressive reaction which would never
be confused with stupor. On the other hand, deep stupors very frequently
are terminated by manic reactions, and if not by such means, recovery
seems to occur merely in virtue of a gradual attenuation of the stupor
symptoms. Rarely do we see a change to depression or anxiety heralding
improvement. This tendency of the stupor reaction to remain pure or
change to hypomania is a peculiarity which seems to put stupor in a
class by itself among the manic-depressive reactions, as all the other
mood reactions frequently change from one to the other.

Although apathy is the central pathognomonic symptom of stupor
conditions, there are other mood anomalies to be noted. One of these is
the tendency for inconsistency in, as well as reduction of, the
expression of emotion. For instance