Kraepelin, however, pointed out the fact that there was another group still unaccounted for—the anxious depressions of later life, which he included under the designation of involution melancholia and which did not belong to the manic-depressive group. This he described as being preeminently a depression associated almost always with anxiety and fear as prominent symptoms. Accompanying this condition there are usually ideas of poverty, sin, or impending danger of some kind. Delusions of self-accusation are quite common. Anxious restlessness or agitated excitement is to be expected in a majority of the cases. There is usually no clouding of the consciousness, although, as Hoch expresses it, "the mental horizon may be more or less narrowed to the depressive ideas." The memory as a rule is not impaired. Hallucinations of sight and hearing are often present. Somatic delusions of a hypochondriacal nature occur. Insomnia is usually marked. The tendency of the disease is towards deterioration. Retardation and psychomotor inactivity are not to be expected. Melancholia is to be differentiated from manic-depressive insanity by the prominence of anxiety and apprehension, the absence of any retardation or psychomotor inhibition, the unusual frequency of self-accusation with ideas of sinfulness, the clearness of the sensorium, the comparatively unfavorable prognosis and the great frequency of suicidal impulses. The age, and the absence of previous attacks, is, of course, exceedingly important in arriving at a diagnosis. The onset of the disease is usually between the ages of forty and sixty, but not infrequently it begins with the menopause in women, and Kraepelin states that sixty per cent of the cases occur in the female sex. He found a history of defective heredity very common. The precipitating factor is often some mental shock, the illness or death of friends, or disasters of various kinds. No distinctive pathology of the disease has been described by Kraepelin. He was uncertain as to the rôle played by arteriosclerosis in its etiology. Diefendorf[283] reported that about one-third of the cases made complete recoveries; twenty-three per cent were able to return to their previous surroundings; twenty-six per cent terminated in an advanced state of deterioration and nineteen per cent died within a period of two or three years.