Loneliness in Personality Disorders.

The number of loneliness studies varied greatly among different PDs with most studies conducted in borderline PD. Across PDs, loneliness was associated with the severity of psychopathological symptoms and with several AMPD trait domains. Consequently, loneliness may contribute to PD severity and further impair personality functioning. Loneliness and PD share intra- and interpersonal factors (i.e., increased rejection sensitivity, information processing biases, social withdrawal) and common origins in childhood maltreatment that may explain their close association. Future research needs to investigate mechanisms on how loneliness and core characteristics of PD mutually reinforce each other in order to therapeutically address loneliness in PD.