Schizoid Personality Disorder

Schizoid Personality Disorder

Definition

The schizoid personality disorder (SZPD) is a pervasive pattern of social detachment and restricted emotional expression. Introver-sion (versus extraversion) is one of the fundamental dimensions of general personality functioning. Facets of introversion include low warmth (e.g., cold, detached, impersonal), low gregarious-ness (socially isolated, withdrawn) and low positive emotions (reserved, constricted or flat affect, anhedonic), which define well the central symptoms of SZPD (see Table 62.1). The presence of SZPD is indicated by four or more of the seven diagnostic criteria presented in the DSM-IV criteria for SZPD.

Etiology and Pathology

A fundamental distinction for schizophrenic symptomatology is between positive and negative symptoms. Positive symptoms include hallucinations, delusions, inappropriate affect and loose associations; negative symptoms include flattened affect, alogia, anhedonia and avolition. SZPD has been conceptualized as rep-resenting subthreshold negative symptoms, comparable to the subthreshold positive symptoms (cognitive–perceptual aberra-tions) that predominate schizotypal personality disorder (STPD). However, a genetic link of SZPD to schizophrenia that cannot be accounted for by comorbid STPD symptomatology has not been well established. Research has supported heritability for the personality dimension of introversion–extraversion and for the association of SZPD with introversion. The central pathology of SZPD does appear to be anhedonic deficits, or an excessively low ability to experience positive affect. Psychosocial models for the etiology of SZPD are lacking. It is possible that a sus-tained history of isolation during infancy and childhood, with an encouragement and modeling by parental figures of interpersonal withdrawal, indifference and detachment could contribute to the development of schizoid personality traits.

Differential Diagnosis

SZPD can be confused with the schizotypal and avoidant person-ality disorders as both involve social isolation and withdrawal. Schizotypal personality disorder, however, also includes an intense social anxiety and cognitive–perceptual aberrations. The major distinction with avoidant personality disorder is the absence of an intense desire for intimate social relationships. Avoidant persons will also exhibit substantial insecurity and inhibition, whereas the schizoid person is largely indifferent toward the reactions or opin-ions of others.

The presence of premorbid schizoid traits can have prog-nostic significance for the course and treatment of schizophrenia but, more importantly, it might not be meaningful to suggest that a person has a schizoid personality disorder that is independent of or unrelated to a comorbid schizophrenia. The negative, pro-dromal and residual symptoms of schizophrenia resemble closely the features of SZPD. Once a person develops schizophrenia, a diagnosis of SZPD can become rather pointless as all of the schiz-oid symptoms can then be understood as (prodromal or residual) symptoms of schizophrenia.

Epidemiology and Comorbidity

Approximately half of the general population will exhibit an introversion within the normal range of functioning. However, only a small minority of the population would be diagnosed with a schizoid personality disorder. Estimates of the prevalence of SZPD within the general population have been less than 1% and SZPD is among the least frequently diagnosed personality disor-ders within clinical settings. Many of the persons who were diag-nosed with SZPD prior to DSM-III are probably now diagnosed with either the avoidant or the schizotypal personality disorders and prototypic (pure) cases of SZPD are likely to be quite rare within the population.

Course

Persons with SZPD are socially isolated and withdrawn as chil-dren. They may not have been accepted well by their peers, and may have even borne the brunt of some ostracism (American Psychiatric Association, 2000). As adults, they have few friend-ships. The friendships that do occur are likely to be initiated by their peers or colleagues. They have few sexual relationships and may never marry. Relationships fail to the extent to which the other person desires or needs emotional support, warmth and intimacy. Persons with SZPD may do well and even excel within an occupation, as long as substantial social interaction is not required. They prefer to work in isolation. They may eventu-ally find employment and a relationship that is relatively com-fortable, but they could also drift from one job to another and remain isolated throughout much of their life. If they do eventu-ally become a parent, they have considerable difficulty providing warmth and emotional support, and they may appear neglectful, detached and disinterested.

Treatment

Prototypic cases of SZPD rarely present for treatment, whether it is for their schizoid traits or a concomitant Axis I disorder. They feel little need for treatment, as their isolation is often egosyn-tonic. Their social isolation is of more concern to their relatives, colleagues, or friends than to themselves. Their disinterest in and withdrawal from intimate or intense interpersonal contact is also a substantial barrier to treatment. They at times appear depressed but one must be careful not to confuse their anhedonic detach-ment, withdrawal and flat affect with symptoms of depression.

If persons with SZPD are seen for treatment for a concomi-tant Axis I disorder (e.g., a sexual arousal disorder or a substance dependence) it is advisable to work within the confines and limi-tations of the schizoid personality traits. Charismatic, engaging, emotional, or intimate therapists can be very uncomfortable, for-eign and even threatening to persons with SZPD. A more busi-ness-like approach can be more successful.

It is also important not to presume that persons with SZPD are simply inhibited, shy, or insecure. Such persons are more appropriately diagnosed with the avoidant personality disorder. Persons with SZPD are perhaps best treated with a supportive psychotherapy that emphasizes education and feedback concern-ing interpersonal skills and communication. One may not be able to increase the desire for social involvements but one can increase the ability to relate to, communicate with and get along with others. Persons with SZPD may not want to develop intimate relationships but they will often want to interact and relate more effectively and comfortably with others. The use of role playing and videotaped interactions can at times be useful in this respect. Persons with SZPD can have tremendous difficulty understand-ing how they are perceived by others or how their behavior is unresponsive to and perceived as rejecting by others.

Group therapy is often useful as a setting in which the patient can gradually develop self-disclosure, experience the interest of oth-ers, and practice social interactions with immediate and supportivefeedback. However, persons with SZPD are prone to being rejected by a group due to their detachment, flat affect and indifference to the feelings of others. If the group is patient and accepting, they can benefit from the experience.

There have been many studies on the pharmacologic treat-ment of the schizotypal PD but no comparable studies on SZPD. The schizotypal and schizoid PDs share many features, but the responsivity of the schizotypal PD to pharmacotherapy will usu-ally reflect schizotypal social anxiety and cognitive–perceptual aberrations that are not seen in prototypic, pure cases of SZPD.