Effectiveness of Intensive Short-Term Dynamic Psychotherapy on Irritable Bowel Syndrome Severity in Patients with Obsessive-Compulsive Personality Disorder

Objective: This study aimed to evaluate the effectiveness of Davanloo’s intensive short-term dynamic psychotherapy (ISTDP) in reducing irritable bowel syndrome (IBS) symptom severity among patients with comorbid obsessive-compulsive personality disorder (OCPD).

Methods and Materials: A quasi-experimental pretest–posttest control-group design with a three-month follow-up was employed. Thirty patients diagnosed with IBS and OCPD were recruited from treatment centers in Tehran, Iran, through convenience sampling and randomly assigned to experimental (n = 15) and control (n = 15) groups. The experimental group received 15 individual 90-minute ISTDP sessions, whereas the control group received no psychological intervention. IBS severity was assessed using the Irritable Bowel Syndrome Symptom Severity Scale. Data were analyzed using repeated-measures ANOVA and Bonferroni comparisons.

Findings: Mean IBS severity scores decreased from 277.30 ± 8.39 at pretest to 272.10 ± 8.20 at posttest and 271.10 ± 8.65 at follow-up in the experimental group. Corresponding control-group scores were 276.00 ± 6.91, 275.08 ± 6.80, and 274.50 ± 6.76. Significant effects were reported for time (F = 237.90, p = .001, partial η² = .895), group (F = 6.53, p = .030, partial η² = .239), and time × group interaction (F = 97.50, p = .001, partial η² = .770). Posttest-to-follow-up differences were nonsignificant (p = .055).

Conclusion: ISTDP was associated with reduced IBS symptom severity, with improvements maintained at three-month follow-up. Larger controlled studies are warranted.