The relationship between
schizoid personality disorder (SPD) and
avoidant personality disorder
Avoidant personality disorder (AvPD) is a Cluster C personality disorder characterized by excessive social anxiety and inhibition, fear of intimacy (despite an intense desire for it), severe feelings of inadequacy and inferiority, and an overre ...
(AvPD) has been a subject of controversy for decades.
Today it is still unclear and remains to be seen if these two personality disorders are genuinely distinct, but overlapping, personality disorders, or if they are merely two different
phenotypic
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...
expressions of the same underlying disorder. Both have been associated with a shared genetic risk factor and the same
polymorphism within the
ANKK1
Ankyrin repeat and kinase domain containing 1 (ANKK1) also known as protein kinase PKK2 or sugen kinase 288 (SgK288) is an enzyme that in humans is encoded by the ''ANKK1'' gene. The ANKK1 is a member of an extensive family of the Ser/Thr protei ...
gene. There is also some evidence that AvPD (like SPD) is a personality disorder of the
schizophrenia spectrum.
Originally, schizoid personality disorder involved social avoidance combined with marked
ambivalence Ambivalence is a state of having simultaneous conflicting reactions, beliefs, or feelings towards some object. Stated another way, ambivalence is the experience of having an attitude towards someone or something that contains both positively and neg ...
regarding the desirability of social contact. It included indifference or even cold disdain oscillating with longing for normal relationships. Through the efforts of
Theodore Millon
Theodore Millon () (August 18, 1928 – January 29, 2014) was an American psychologist known for his work on personality disorders. He founded the ''Journal of Personality Disorders'' and was the inaugural president of the International Society ...
, this complex idea was later divided across two disorders with the emergence of a separate AvPD construct and the idea of ambivalence was lost.
According to the differential diagnosis guidelines provided in the text of the DSM-IV the two conditions are distinguished by the extent to which the individual desires social contact versus being indifferent to it. But such distinctions are often difficult to apply in practice, as patients often have unclear, marginal, or shifting status on those elements thought most crucial for differential diagnosis. In the case of the avoidant and schizoid PDs, however, both the problem and its solution may be more academic than real. First, research indicates that all of the avoidant symptoms except social withdrawal correlate negatively with the schizoid symptom list and that differential diagnosis is not difficult. Second, as pointed out by Benjamin (1993), schizoid PD is exceedingly rare and the diagnostic quandary may never occur in practice.
However, new research shows that both PDs are linked to hypersensitivity.
[Daniel Winarick]
Psychology Today, Jan. 2017.
See also
*
Counterdependency
References
Personality disorders