Four of the following seven specific symptoms should be present:
Avoids occupational activities that involve significant interpersonal contact, because of fears of criticism, disapproval, or rejection
is unwilling to get involved with people unless certain of being liked
shows restraint within intimate relationships because of the fear of being shamed or ridiculed
is preoccupied with being criticized or rejected in social situations
is inhibited in new interpersonal situations because of feelings of inadequacy
views self as socially inept, personally unappealing, or inferior to others
is unusually reluctant to take personal risk or to engage in any new activities because they may prove embarrassing

Differential diagnosis
In contrast to social anxiety disorder, a diagnosis of avoidant personality disorder (AvPD) also requires that the general criteria for a personality disorder be met. According to the DSM-5, avoidant personality disorder must be differentiated from similar personality disorders such as dependent, paranoid, schizoid, and schizotypal. But these can also occur together; this is particularly likely for AvPD and dependent personality disorder. Thus, if criteria for more than one personality disorder are met, all can be diagnosed.There is also an overlap between avoidant and schizoid personality traits (see Schizoid avoidant behavior) and AvPD may have a relationship to the schizophrenia spectrum.Avoidant personality disorder must also be differentiated from the autism spectrum, specifically Asperger syndrome.
In addition to this, AvPD is more prevalent in people who have comorbid social anxiety disorder and generalised anxiety disorder than in those who have only one of the aforementioned conditions.Some studies report prevalence rates of up to 45% among people with generalized anxiety disorder and up to 56% of those with obsessive–compulsive disorder. Posttraumatic stress disorder is also commonly comorbid with avoidant personality disorder.Avoidants are prone to self-loathing and, in certain cases, self-harm. Substance use disorders are also common in individuals with AvPD—particularly in regard to alcohol, benzodiazepines, and opioids—and may significantly affect a patients prognosis.Earlier theorists proposed a personality disorder with a combination of features from borderline personality disorder and avoidant personality disorder, called "avoidant-borderline mixed personality" (AvPD/BPD). Causes
Causes of AvPD are not clearly defined, but appear to be influenced by a combination of social, genetic and psychological factors. The disorder may be related to temperamental factors that are inherited.Specifically, various anxiety disorders in childhood and adolescence have been associated with a temperament characterized by behavioral inhibition, including features of being shy, fearful and withdrawn in new situations. These inherited characteristics may give an individual a genetic predisposition towards AvPD.Childhood emotional neglect and peer group rejection are both associated with an increased risk for the development of AvPD. Some researchers believe a combination of high-sensory-processing sensitivity coupled with adverse childhood experiences may heighten the risk of an individual developing AvPD.