DEVELOPMENT — DEVELOPMENTAL INSANITIES
to adaptation, growth to Accommodation
(q. v.). In addition to the topics referred to,
see Embryology.
Literature : see topics mentioned above ;
Hyatt, Science, N.S., Jan. 27, 1897 ;
HAECKEL,Gen.Morphol.(i866). (j.m.b.,e.b.p.)
Development (mental) : see Mental De¬
velopment, and Evolution (mental).
Development Formula : see Symbolic
Logic.
Developmental Insanities: Ger. Entwick¬
lungspsychosen ; Fr. psychoses du développe¬
ment ; Ital. psicosi dello sviluppo (e.g. della
puhertà). Those nervous disorders which tend
to appear at certain periods in the growth and
development of the brain.
The bringing to complete fruitage of the
highest evolution in nature is a most delicate
process, subject to dangers of many kinds, and
incident to different periods. "While these may
be aggravated by unhygienic conditions, the
determining factor is heredity. ‘ A bad or a
good heredity means more during development
than after/ Most of the disorders of develop¬
ment are accordingly regarded as manifesta¬
tions of nervous instability, or of a neurotic dia¬
thesis. Such taint may be so slight that, under
ordinary circumstances, the individual would
pass through his normal span of years without
mental disorder or marked abnormality ;
but under the influence of misfortune or ex¬
citement, particularly if it occur at critical
periods in his life, he is apt to exhibit patho¬
logical symptoms. Those bearing upon them
the marks or stigmata of Degeneration (q. v.)
are specially prone to developmental neuroses.
Developmental disorders in children are
apt to take the form of convulsions, delirium,
night-terrors, somnambulism, and the like.
During dentition, convulsion is the typical
form of manifestation of an unstable brain.
The delirium may be connected with a distinct
fever, but the high temperature does not of
itself lead to delirium except in the predis¬
posed brain.
The developmental neuroses incident to
puberty and adolescence are of supreme im¬
portance ; for these periods are recognized as
the ones when breakdown is most imminent,
when the tyranny of heredity is most apt
to make itself felt, when the decadence of
the unfit begins to appear. Epilepsy and,
especially, hysteria are apt to appear in the
years following puberty.
The ages from twenty to twenty-five are
most liable to mania and neurasthenia ; and
the percentage of cases of insanity which occur
at this period, in which hereditary influences
can be traced, is unusually large. Many of the
forms of mental disturbance incident to this
period, while not technically insanities, are yet
significant. A characteristic form of minor
psychosis may appear as an exaggerated self-
will : the youth or maiden becomes ungovern¬
able, breaks out into attacks of violence,
becomes lazy, may be prone to deceit and lying,
may leave home without reason, or create
scandal. In all this there is a characteristic
periodicity, periods of abandonment and ex¬
cess giving way to periods of propriety and
self-restraint. It would be misleading to re¬
gard such attacks as insanity, but they are
closely related causally to the influences which
produce true insanity. The form of insanity
usually described as the insanity of adolescence
is characterized by a maniacal tendency
(seventy-eight per cent.) and a motor restless¬
ness. ‘ The maniac is, in the male sex, restless,
boisterous, full of mock-heroic pseudo-manli¬
ness, obtrusive pugnaciousness, with often a
morbid sentimentality ; while in the female
sex we find also restlessness, with lack of
self-control, intolerance of control by others,
impulsiveness, hysterical obtrusiveness, and
emotional perversion. In both sexes we
naturally find strong and perverted sexual
ideas and practices/ Periodicity of attack and
remission is particularly characteristic, and is
related, in women especially, to the periodicity
of sexual functions. In about one-third of all
cases the ending is secondary dementia—a
severe decay of mental functions, comparable
to extreme idiocy. Such dementia, however,
may be consistent in some cases with the
spasmodic, but transitory, display of latent
mental powers. Some cases recover once or
twice with years of sanity, but in the end pass
into true dementia. Less frequently the
adolescent insanity is of a melancholic type,
still showing remissions, but not so definitely
as in maniacal cases ; there is apt to be
hypochondria and extreme concentration upon
one’s self. Suicidal tendencies may occur;
religious depression and delusions are frequent.
Such cases when persistent developinto forms of
stupor—more common in females than in males.
Masturbation in males, and hysterical symp¬
toms in females, are the chief complications.
Akin to adolescent insanities are those con¬
nected with childbirth, with the climacteric,
and with senility. All these relate to periods
of development in the progress from birth to
death, and are dominated by hereditary in¬
fluences and endowments. For description of
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