Schizoid personality disorder

Schizoid personality disorder (ScPD) together with schizotypal (SPD) personality disorder and paranoid personality disorder belongs to the cluster A personality disorders.

• it is a rare disease with a prevalence of <1% in the general population
  • in the homeless population the prevalence is higher (1,2)

People with schizoid personality disorder characteristically have little or no social involvement - they tend to be solitary, have no sense of humour, and are felt to be dull (2).

• the stereotype of this sort of person is tall, asthenic build, gawky appearance with ill-fitting, unfashionable clothes

ScPD is considered to be closely related to schizophrenia due to the following reasons:

• ScPD is frequently seen prior to schizophrenia onset
  • a study carried out on patients with schizophrenia found that 85% of subjects showed premorbid personality disorders, including ScPD (27.5%) and SPD (12.5%)
• it also has a frequent comorbid association with schizophrenia
• the high transition rate to psychotic disorders

The Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text rev. (DSM-IV-TR) criteria for diagnosis of Schizoid Personality Disorder are:

A. A pervasive pattern of detachment from social relationships and a restricted range of expression of emotions in interpersonal settings, beginning by early adulthood and present in a variety of contexts, as indicated by four (or more) of the following:

• neither desires nor enjoys close relationships, including being part of a family
• almost always chooses solitary activities
• has little, if any, interest in having sexual experiences with another person
• takes pleasure in few, if any, activities
• lacks close friends or confidants other than first-degree relatives
• appears indifferent to the praise or criticism of others
• shows emotional coldness, detachment, or flattened affectivity

B. Does not occur exclusively during the course of schizophrenia, a mood disorder with psychotic features, another psychotic disorder, or a pervasive developmental disorder and is not due to the direct physiological effects of a general medical condition.

Note: if criteria are met prior to the onset of schizophrenia, add “premorbid” (e.g., “schizoid personality disorder [premorbid]”) (2)

Reference:

• (1) Via E et al. Structural alterations of the pyramidal pathway in schizoid and schizotypal cluster A personality disorders. Int J Psychophysiol. 2016;110:163-170
• (2) Angstman KB, Rasmussen NH. Personality disorders: review and clinical application in daily practice. Am Fam Physician. 2011;84(11):1253-60.