TABLE 3.

Studies of IPT for chronic posttraumatic stress disorder

Study	Design	IPT	Adaptation	Outcome	Remarks and effect sizes
Bleiberg and Markowitz[12]	Open trial N = 14	14 weekly sessions	Exposure to trauma reminders prohibited	Pre/post-CAPS 67 → 25 Attrition: 7%	Large effect sizes: CAPS d = 1.8
Robertson et al.[50]	Open trial N = 13	8 weekly group IPT sessions	“Specially prepared” treatment manual; standard group IPT?	“Modest” IES improvement Attrition: 0%	Results stable on 3-month f/u; ES: IES subscales r = 0.63–0.67
Ray and Webster[51]	Open trial N = 9	8 weekly 2-hr group IPT sessions	Based on group IPT manual (Wilfley et al., 2000)	IES significantly improved (P < .05) Attrition: 0%	Some symptomatic slippage on 2-month f/u; (ES: not calculable)
Krupnick et al.[55]	RCT: IPT vs. WL N = 48	16 weekly 2-hr group IPT sessions	Adapted for low-income, highly traumatized minority women	IPT > WL (CAPS, P < .001) Attrition: 29% IPT	Gains persisted at 4-month f/u ES: CAPS d = 1.31
Campanini et al.[57]	Open augmentation of med trial N = 40	16 weekly 2-hr group IPT	Similar to Krupnick et al., IPT did not focus on trauma exposure	CAPS 72 → 37, with large effect size (1.2) Attrition: 17%	Medication nonresponders; ES: CAPS d = 1.17

CAPS, Clinician-Administered PTSD Scale; ES, effect size (Cohen's d); f/u, follow-up; IES, Impact of Events Scale; IPT, interpersonal psychotherapy; RCT, randomized controlled trial; WL, waiting list.