Schizoid personality disorder
Schizoid personality disorder is identified as a personality disorder characterized by a lack of interest in social relationships, a tendency towards a solitary lifestyle and emotional coldness.   The disorder is rare as compared to other personality disorders, and its prevalence is estimated at less than 1% of the general population.
Schizoid personality disorder falls within the A cluster of personality disorders, along with Paranoid personality disorder and Schizotypal personality disorder 
Note: The American Psychiatric Association, which publishes the Diagnostic and Statistical Manual of Mental Disorders, forbids the unauthorized reproduction of their diagnostic criteria. A narrative of the DSM-IV-TR criteria follows.
The schizoid character demonstrates a pervasive pattern of detachment from social relationships, as well as restricting the range of emotional expression in interpersonal settings. This profile evidences itself beginning by early adulthood and is typically present across situations.
The schizoid character neither desires nor enjoys close relationships, including being part of a family, almost always chooses solitary activities, has little interest in sexual experiences with another person, takes pleasure in few activities, lacks close friends , appears indifferent to both the praise or criticism of others, and typically displays emotional coldness, detachment, or a flattened affect.
It is important to demonstrate that the behaviors outlined above do not occur exclusively during the course of schizophrenia, a mood disorder with psychotic features, psychotic disorder, or within the context of pervasive developmental disorder, as well as not being due to the direct physiological effects of a general medical condition. 
- ↑ 1.0 1.1 1.2 American Psychiatric Association. (2000). Diagnostic and Statistical Manual of Mental Disorders. American Psychiatric Press: Washington DC
- ↑ Authur S. Reber- Dictionary of Psychology, Penguin p.690 (1995)
- ↑ Weismann, M. M. (1993). "The epidemiology of personality disorders. A 1990 update.". Journal of Personality Disorders (Spring issue, Suppl.): 44-62. .
|Cluster A (Odd): Schizotypal | Schizoid | Paranoid|
Cluster B (Dramatic): Antisocial | Borderline | Histrionic | Narcissistic
Cluster C (Anxious): Dependent | Obsessive-Compulsive | Avoidant