Which disorder is characterized by difficulty developing relationships and discomfort in social situations?

The disorder characterized by difficulty developing relationships and discomfort in social situations is Schizotypal Personality Disorder. Individuals with this disorder often experience significant anxiety in social settings and may exhibit peculiar behaviors or thoughts that hinder their ability to form close relationships. They may feel uncomfortable in social interactions and may prefer to be alone, leading to a limited social network.

The criteria for Schizotypal Personality Disorder include odd beliefs or magical thinking, unusual perceptual experiences, and eccentric behavior, all of which contribute to their social discomfort and fragile relationships. This disorder stands out from the others mentioned because, while borderline, narcissistic, and histrionic personality disorders involve interpersonal difficulties, they do not primarily stem from the same level of social anxiety or discomfort specific to Schizotypal Personality Disorder.