By Vidya Koesmahargyo
Personality disorders (PD) can be generalized into three clusters of patterns of thinking and behavior. Cluster A personality disorders are characterized by odd, eccentric thinking or behavior, including schizoid, schizotypal, and paranoid PDs. Cluster B personality disorders are characterized by dramatic, overly emotional or unpredictable thinking or behavior, including PDs such as borderline and antisocial personality disorder. Cluster C personality disorders are characterized by anxious, fearful thinking or behavior, such as obsessive compulsive and avoidant PDs. (American Psychological Association, 2013)
Schizoid and schizotypal personality disorders are characterized by long-standing patterns of detachment from social relationships and difficulty in establishing and maintaining those relationships. Although the lack of close personal relationships occur in both disorders (attributed to cluster A disorders), each disorder has their own characteristic symptoms.
Symptoms of schizotypal personality disorder can include peculiar, eccentric or unusual thinking, peculiar style of speech, and limited or inappropriate emotional responses. For example, a person with schizotypal PD may have lasting suspicions or paranoid ideas, or express anger at good news, and speak at irregular intervals. In contrast, symptoms of schizoid personality disorder include a high preference of being alone or solitary activities, lack of understanding of social cues, little desire for intimacy or sexual relationships, indifference or lack of motivation at school or work. Most of the symptoms for both these disorders result in the individual's lack of close social relationships or their difficulty to maintain them. (PsychCentral)
Schizotypal and schizoid personality disorder may somewhat resemble schizophrenia, a severe mental illness that affects the way people perceive reality, emotions, and behavior. People with schizophrenia have symptoms that categorize into positive and negative symptoms. Positive symptoms, which refers to psychotic behaviors that include hallucinations, delusions, and unusual or dysfunctional ways of thinking can relate to patterns of thinking in Schizotypal PD. Similarly Schizoid PD may seem relate to negative symptoms, which are associated with disruptions to normal emotions and behaviors such as reduced expression of emotions, reduced feelings of pleasure and motivation in everyday life.
Despite the resemblance, there is a marked difference between schizoid and schizotypal personality disorders and schizophrenia: neither show symptoms of explicit hallucinations or delusions, especially in schizotypal PD, where the peculiar thoughts and behavior can be seen as mild positive symptoms. In this case, a person with schizophrenia might believe that their thoughts are being controlled by an outside force, and act out in fear, while a person with schizotypal PD may often think about the notion and have similar notions that are not quite delusions.
There is some indication that there is a strong genetic relation between the disorders, and relatives of people with schizophrenia are at increased risk of developing either schizotypal or schizoid personality disorder. Some experts argue that schizotypal personality disorder might be a mild form of schizophrenia, whereas other researchers suggest there are also important differences in other brain functions that prevent people with schizotypal and schizoid personality disorders from developing schizophrenia. (Hoermann)
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed., text rev.). doi:10.1176/appi.books.9780890423349
Bressert, S. (2014). Schizoid Personality Disorder Symptoms. Psych Central. Retrieved on February 11, 2016, from http://psychcentral.com/disorders/schizoid-personality-disorder-symptoms/
Hoermann, S. (2009, August 09). Schizotypal Personality Disorder and Schizophrenia. Retrieved February 13, 2016, from https://www.mentalhelp.net/blogs/schizotypal-personality-disorder-and-schizophrenia/