Canadian psychoanalyst Habib Davanloo (1927-2023) developed this therapy in the 1960’s
Intensive short-term dynamic psychotherapy produces large, lasting effects on treatment-resistant depression
STUDY: Johansson R et al, Frontiers in Psychiatry 2026;
STUDY TYPE: Randomized controlled trial reanalysis
FUNDING: Independent
Background
Intensive Short-Term Dynamic Psychotherapy (ISTDP) is a brief psychodynamic therapy (10 to 40 sessions) that helps patients access avoided emotions by actively confronting psychological defenses. Several trials have shown it works for treatment-resistant depression, but does it work the way its theory claims: by reducing emotional repression, which then reduces negative affect, which then lifts depression.
The Study
- 86 Iranian adults with treatment-resistant major depressive disorder were randomized to 20 sessions of ISTDP over 10 weeks or a waitlist.
- Depression and process measures (emotional repression, negative affect, overall distress) were assessed at baseline, post-treatment, and 3-month follow-up.
- This was a reanalysis of a prior randomized controlled trial, adding mediation and cross-lagged analyses that the original study omitted.
Results
ISTDP produced large effects on depression at post-treatment (Cohen’s d = 1.68) that grew further at 3-month follow-up (d = 2.50). The waitlist group showed virtually no change across the same period.
All four process measures improved substantially: emotional repression (d = 2.76), negative affect (d = 1.96), distress (d = 2.95), and suppression of aggression (d = 2.75). But none of these changes mediated the depression improvement. Neither emotional repression nor negative affect preceded or predicted the drop in depression scores. Distress appeared to mediate 54% of the effect, but this was driven entirely by the depression subscale embedded within the distress measure.
Cross-lagged analyses confirmed the same pattern. All variables changed together, not sequentially. ISTDP doesn’t appear to work by first unlocking repression, then improving affect, then easing depression. Everything changes at once.
Limitations
- Only three measurement occasions, months apart, were too coarse to capture session-by-session dynamics.
- All process measures were self-report, which can’t adequately capture unconscious processes central to ISTDP theory.
- No active comparator, only a waitlist control.
- Small sample, Iranian adults only.
Practice Implications
- This study adds to the list of small trials that find a big effect with ISTDP therapy in difficult to treat depression.
- Having watched some of Davanloo’s work on video, my guess is the therapist takes a very active role, addressing the avoidance and passivity that perpetuate depression.
- Here’s the original guide.
— Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
