Review of Empirical Literature Studies
Very few systematic studies of treatment for avoidant personality disorder have been performed, and most of these were in the area of nonpharmacological therapy. Various therapies have been used, including psychodynamic, exposure, rational-emotive, cognitive, and interpersonal therapies, as well as social skills training. Therapy has been carried out in both individual and group formats, and several studies of treatment for social phobia have shown improvement in avoidant personality features as well.
In early studies of avoidant personality disorder, patients receiving behavioral treatments improved significantly more than waiting-list control groups. Treatments used were graduated exposure, social skills training, and systematic desensitization. In another study, Stravynski and colleagues reported significant improvement on most measures for groups treated with social skills training alone or in combination with cognitive modification. Although specific results for avoidant personality disorder were not reported, researchers found that two forms of short-term psychodynamic therapy, when applied for an average of 40 weeks, resulted in significant improvement in patients with DSM-III-R Cluster C personality disorders. In an open clinical trial, 24 patients with avoidant personality disorder received a series of 52 sessions of time-limited supportive-expressive dynamic psychotherapy. At the end of treatment, only 39% still met the criteria for avoidant personality disorder.
The cognitive theory of personality disorders has become one of the main theoretical orientations in the personality disorder literature. Cognitive-behavioral therapy (CBT), which has become a mainstay of treatment in anxiety disorders, has been shown in several studies to be effective in decreasing social phobia as well as avoidant personality traits. However, many patients do not benefit sufficiently from CBT. Turner and colleagues (1996) estimated that about 52% of socially phobic patients benefit from this treatment. Chambless and colleagues, in a 6-month follow-up study, reported that one of the predictors of greater improvement with cognitive-behavioral group therapy in social phobia was a lower level of avoidant personality traits. Scholing and Emmelkamp attempted to (partially) replicate the above study in an 18-month follow-up study and found that the presence of avoidant personality traits showed no predictive value for the group of 50 subjects who completed the study. However, for the subgroup with generalized social phobia, avoidant traits did predict less favorable results, whereas for the discrete social phobia group, these traits predicted better results. Two meta-analyses of treatment results in CBT for social phobia indicated that exposure in vivo results in significant improvement in self-reported social anxiety with no enhanced benefit from cognitive interventions.
Behavioral treatment strategies have been shown to be beneficial for patients with avoidant personality disorder, although some do not benefit and others benefit only moderately. Alden and Capreol studied 76 outpatients with avoidant personality disorder who had varied responses to behavioral treatment in an effort to determine how differences in patients’ problematic interpersonal behavior influenced treatment response. Those who had interpersonal problems related to distrustful or angry behavior benefited from graduated exposure but not skills training, whereas those who had problems related to being coerced and controlled by others benefited from both treatments.
Another form of psychotherapy that has been touted as helpful for avoidant personality traits is interpersonal therapy (IPT). Barber and Muenz examined the database from the Treatment for Depression Collaborative Research Program to test the hypothesis that cognitive therapy is more effective than IPT for depressed patients with an elevated level of avoidant personality traits, whereas the reverse is true for those with elevated levels of obsessive personality traits. They found that their hypothesis held true in predicting response to the treatment aimed at depressive symptoms. They speculated that their findings are consistent with the “theory of opposites” (i.e., that helpful therapy, especially for Axis II disorders, requires the therapist to behave in a way that is antithetical to the interpersonal behavior, personality pattern, and cognitive style of the patient). Although the treatments did not specifically address Axis II issues, it is noteworthy that subjects with the same Axis I disorder responded differentially to treatments based on their underlying Axis II psychopathology. The positive response to cognitive therapy for those with avoidant personality lends support to the view that individuals with this personality disorder can benefit from cognitive restructuring in addition to exposure therapy and may, in fact, benefit more than those with only the Axis I social anxiety disorder.
Although data for the medical treatment of avoidant personality disorder are limited, there is a growing body of literature on such treatment for generalized social phobia, a disorder that, as we have seen, frequently overlaps with avoidant personality disorder. Attempts continue to address the issue of overlap between these two disorders and to draw a somewhat greater distinction between them, and much of the available literature on the treatment of generalized social phobia, can be used to inform our approach to treatment of avoidant personality disorder; some of this literature directly addresses the effects that treatment has on comorbid avoidant personality disorder.
A controlled study by Liebowitz et al., which showed efficacy for the monoamine oxidase inhibitor (MAOI) phenelzine in social phobia, also provided evidence for the usefulness of this drug in treating the avoidant personality traits in these subjects. In another controlled study of similar design, the efficacy of the reversible MAOI moclobemide was similar to that of phenelzine in the treatment of patients with social phobia who had been chronically impaired and socially disabled before treatment. The authors of a third study specifically addressed the avoidant personality traits that are commonly part of the clinical presentation of patients with social phobia. They found that although most traits improved during alprazolam treatment, all but one returned to baseline levels after treatment.
Although MAOIs, especially phenelzine, have been considered the gold standard in drug treatment of social phobia, the SSRIs have become the generally accepted first-line treatment for social phobia because of the dietary restrictions and significant adverse events associated with the MAOIs. The SSRIs also are the most studied group of drugs used in the treatment of social phobia, with controlled trials showing efficacy for fluvoxamine, sertraline, and paroxetine. The benzodiazepine clonazepam also has shown efficacy in social phobia, and the anticonvulsant gabapentin was recently reported to be effective in a multicenter trial.
The drug venlafaxine, which acts to enhance both serotonergic and noradrenergic transmission in the brain, has been reported in several open trials to be effective in treating social phobia. In a 12-week retrospective chart study, Kelsey reported a good clinical response with venlafaxine in SSRI-resistant patients with social anxiety disorder but not with avoidant personality disorder. In the more recent 15-week trial by Altamura and colleagues, patients who were nonresponsive to SSRIs received venlafaxine, and the effect of avoidant personality disorder on the response to venlafaxine was assessed. Rapid remission of both the social phobia and the avoidant personality disorder symptoms occurred.
Anecdotal support for other medical treatments is found in an open study by Deltito and Stam, who followed up 20 patients with DSM-III-R avoidant personality disorder during a naturalistic treatment period of 2 years. In this study, treatment success was reported for the MAOIs phenelzine and tranylcypromine, as well as for the SSRI fluoxetine. Several other case reports have been published citing the efficacy of fluoxetine in both social phobia and avoidant personality disorder patients, including a series of 12 patients who received treatment in an open trial of several months.
Revision date: July 3, 2011
Last revised: by Jorge P. Ribeiro, MD