This investigation reports changes in interpersonal problems over the
course of outpatient psychotherapy. Endorsement patterns for distress
related to interpersonal problems for patient and non-patient samples
were compared. For the patient sample, a 26-item version of the Invent
ory of Interpersonal Problems was administered at intake and at select
ed sessions of psychotherapy. Three factors were identified: (1) Contr
ol (e.g., It is hard to accept another person's authority over me); (2
) Detached (e.g., I keep other people at a distance too much), and; (3
) Self-effacing (e.g., I worry too much about disappointing other peop
le). Using session 2 as a base, the dose-response curve for the Contro
l scale inflected at session 10 and was followed by a monotonic increa
se in improvement. For the Detached scale, there was an inflection at
session 17 followed by a monotonic increase. The Self-effacing scale d
id not show any response to treatment.