Descriptive psychiatrists approached psychopathology from a medical model consistent with the Hippocratic view, emphasizing identification (i.e., diagnosis) and categorical classification (Havens, 1981; Wilson, 1993). Kraepelin was reportedly the first to identify, describe, and classify “dementia praecox,” later translated and re-conceptualized as schizophrenia by Eugen Bleuler (Bleuler, 1979).
Early descriptive psychiatry viewed different personality types as differentially related to major mental diseases (Kasanin & Rosen, 1929). In the early 20th century, there was widespread interest in describing the personality characteristics of individuals before, during, and after the onset of schizophrenia or dementia praecox within both dynamic and descriptive psychiatry (e.g., see Nannarello, 1953, for a review).
The early descriptive psychiatrists reported the existence of identifiable personality/schizophrenia-related trait patterns marked by social withdrawal and isolation under a variety of labels (e.g., seclusiveness, Kraepelin [1902/1912]; shut-in personality, Hoch ; schizoid character, Bleuler [1924/1951]; and schizoid temperament, Kretschmer ; see Ahktar, 1987; Livesley, Tanney, & West, 1985, for reviews).
Kraepelin and Dementia Praecox
Kraepelin appears to have been among the first to identify common features of pre-morbid schizophrenia, symptomatic schizophrenia, and remitted schizophrenia (cf. Kraepelin, 1902/1912). Kraepelin (1902/1912, p. 66) conceptualized this constellation of personality characteristics—often also witnessed in the family members of patients with dementia praecox—as a pathological temperament, a biologically based predisposition, and labeled it seclusiveness. Kraepelin (1902/1912, p. 66) described seclusive individuals as “shrinking away from the impressions of the world...” with low self-confidence, odd appearance, and an inability to engage in social interaction because of its perceived difficulty.
Furthermore, Kraepelin (1902/1912) viewed the underlying cause for seclusiveness as a constitutional hypersensitivity to the environment, indicating a view of “seclusiveness-based” social withdrawal and isolation as resulting from a propensity to become easily over-stimulated and overwhelmed by external—namely, social—stimuli (McWilliams  as well as Beck, Freeman, & Davis  adopted a similar view of social isolation in schizoid PD).
Kraepelin (1902/1912, p. 67) also pointed out that many seclusive—withdrawn, detached, and isolated—individuals functioned in a stable, non-deteriorating manner without ever developing dementia praecox, signifying a disturbance limited to the appearance of these abnormal traits. This observation highlights the parallel between Kraepelin’s seclusiveness construct and modern day views of cluster A/schizophrenia-spectrum personality disorders.
The Shut-In Personality
Another major influence on current notions of personality patterns marked by social withdrawal and isolation was the work of Hoch (1910; see Ahktar, 1987; Livesley et al., 1985, for reviews). Hoch (1910) described a recognizable personality pattern—the shut-in—that also reportedly usually preceded dementia praecox or schizophrenia. Hoch’s frequently cited (1910) description of the shut-in personality—later viewed as a precursor to both schizoid and avoidant PDs (e.g., Livesley et al., 1985)—follows:
...persons who do not have a natural tendency to be open, and to get into contact with the environment, who are reticent, seclusive, who cannot adapt themselves to situations... often sensitive and stubborn, but the latter more in a passive than in an active way. They show little interest in what goes, often do not participate in the pleasures, cares, and pursuits, of those about them; although often sensitive, they do not let others know what their conflicts are; they... are shy, and have a tendency to live in a world of fancies. This is the shut-in personality. (Hoch, 1910, p. 114)
Essentially, Hoch (1910) identified the co-occurrence of a cluster of personality traits—shyness, sensitivity, rigidity, passivity, detachment, as well as social withdrawal and isolation—that signify a predisposition towards psychosis or schizophrenia. In addition to its similarity to current notions of schizophrenia-spectrum PDs, Hoch’s (1910) definition of the shut-in personality is very similar to (a) DSM-I and DSM-II descriptions of schizoid personality, which even use some of Hoch’s (1910) original language verbatim (cf. DSM-I, APA, 1952) and (b) a mixture of DSM-III and DSM-IV schizoid and avoidant PD features.
Kasanin, J., & Rosen, Z.A. (1929). Clinical variables in schizoid personalities. American Journal of Sociology, 24 (1), 538 – 546.
Kraepelin, E. (1912). Clinical Psychiatry: A Text Book for Students and Physicians (A.R. Diefendorf, trans.). New York: Macmillan Company, 1902. (Abstracted and Adapted from the Seventh German Edition of Kraepelin’s “Lehrbuch der Psychiatre”).
Hoch, A. (1910). Constitutional factors in the demenetia praecox group. Review of Neurological Psychiatry, 8, 463 – 474.
Livesley, J.W., West, M., & Tanney, A. (1985). Historical comment on DSM-III schizoid and avoidant personality disorders. American Journal of Psychiatry, 142 (11), 1344-1347.
Nannarello, J.J. (1953) Schizoid. Journal of Nervous and Metal Disease, 118 (3), 237 – 249.