The case for years of therapy rests on one JAMA meta-analysis, and a re-analysis found a miscalculation
In 2008 a JAMA meta-analysis of 23 studies reported that psychodynamic therapy of a year or more beat shorter therapy by an effect size of 1.8. A 2010 re-analysis found a miscalculation and "no evidence to support claims of superiority".
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: This row is the contest. The 2008 effect size was disputed in print in 2010 for a calculation error, heterogeneity and weak comparators; any reply by the original authors was not read for this row. Both abstracts concern complex, chronic disorders, so neither supports nor refutes long therapy for common problems. Scored below a meta-analysis of randomised trials on purpose.
This is the strongest published case for long term therapy, and the strongest published case against it, on one row, because a reader who sees only one of them has been sold something.
The case for
In 2008 Leichsenring and Rabung published a meta-analysis in JAMA of long term psychodynamic psychotherapy (LTPP), defined as individual psychodynamic therapy "lasting for at least a year, or 50 sessions", in complex mental disorders: personality disorders, chronic and multiple disorders, and complex depression and anxiety. Twenty three studies with 1,053 patients were included, 11 randomised trials and 12 observational studies.
Their headline: "a between-group effect size of 1.8 (95% confidence interval [CI], 0.7-3.4) indicated that after treatment with LTPP patients with complex mental disorders on average were better off than 96% of the patients in the comparison groups (P = .002)." Within group effects across disorders ranged from 0.78 to 1.98. They concluded: "There is evidence that LTPP is an effective treatment for complex mental disorders."
The case against
In 2010 Bhar, Thombs, Pignotti and colleagues re-examined the meta-analysis and the eight studies behind its key comparisons, in Psychotherapy and Psychosomatics. "We found a miscalculation of the effect sizes used to make key comparisons." The claims "depended on a set of small, underpowered studies that were highly heterogeneous in terms of patients treated, interventions, comparison-control groups, and outcomes." LTPP had been compared against "12 types of comparison-controls, including control groups that did not involve any psychotherapy, short-term psychodynamic psychotherapy, and unvalidated treatments." The studies "failed to protect against threats to bias, and had poor internal validity." Their conclusion: "we found no evidence to support claims of superiority of LTPP over shorter-term methods of psychotherapy."
What this does not show
Neither paper settles the question. The 2008 confidence interval (0.7 to 3.4) was wide before anyone re-ran the arithmetic. The critique does not show that long term therapy fails; it shows the evidence that it beats shorter therapy was not sound. The population was people with complex, chronic conditions, so none of it speaks to whether an ordinary course of therapy should run for years.
Worth asking
If someone recommends open ended therapy, what is the evidence for my situation, and how will we know it is working?
Source
Effectiveness of long-term psychodynamic psychotherapy: a meta-analysis — Leichsenring F, Rabung S (2008)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1001/jama.300.13.1551
DOI: 10.1001/jama.300.13.1551
How this was scored
- Study design
- Systematic review of observational studies
- Funding
- Funding not disclosed
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 1,053
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 24, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 60 out of 100 on our published rubric. One caveat travels with that badge: This row is the contest. The 2008 effect size was disputed in print in 2010 for a calculation error, heterogeneity and weak comparators; any reply by the original authors was not read for this row. Both abstracts concern complex, chronic disorders, so neither supports nor refutes long therapy for common problems. Scored below a meta-analysis of randomised trials on purpose. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Effectiveness of long-term psychodynamic psychotherapy: a meta-analysis — Leichsenring F, Rabung S (2008). Published in: Top-tier peer-reviewed journal. DOI: 10.1001/jama.300.13.1551. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Systematic review of observational studies. Funding: Funding not disclosed. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.