A well-defined type of psychosis which as a rule develops gradually and is characterized by the following symptoms:

Impairment of retention (forgetfulness) and general failure of memory more marked for recent experiences; defects in orientation and a general reduction of mental capacity: the attention, concentration and thinking processes are interfered with; there is self-centering of interests, often irritability and stubborn opposition; a tendency to reminiscence and fabrication. Accompanying this deterioration there may occur paranoid trends, depressions, confused states, etc. Certain clinical types should therefore be specified, but these often overlap:

(a) Simple deterioration: Retention and memory defects, reduction in intellectual capacity and narrowing of interests; usually also suspiciousness, irritability and restlessness, the latter particularly at night.

(6) Presbyophrenic type: Severe memory and retention defects with complete disorientation; but at the same time preservation of mental alertness and attentiveness with ability to grasp immediate impressions and conversation quite well. Forgetfulness leads to absurd contradictions and repetitions; suggestibility and free fabrication are prominent symptoms. (The general picture resembles the Korsakow mental complex.)

(c) Delirious and confused types: Often in the early stages of the psychosis and for a long period the picture is one of deep confusion or a delirious condition.

(d) Depressed and agitated types: In addition to the underlying deterioration there may be a pronounced depression and persistent agitation.

(e) Paranoid types: Well-marked delusional trends, chiefly persecutory or expansive ideas, often accompany the deterioration and in the early stages may make the diagnosis difficult if the defect symptoms are mild.

(f) Pre-senile types: The so-called "Alzheimer's disease"; an early senile deterioration which usually leads rapidly to a deep dementia. Reported to occur as early as the fortieth year. Most cases show an irritable or anxious depressive mood with aphasic or apractic symptoms. There is apt to be general resistiveness and sometimes spasticity.