Research review 033
Long-term follow-up of a randomised trial
Short answer
A brief programme of talking therapy during pregnancy was associated with fewer depressive symptoms throughout the first year after childbirth. The sessions addressed relationships and life changes, an approach known as interpersonal therapy.
At one year, around four in every hundred participants in the therapy group had a diagnosis of depression, compared with around 13 in every hundred in the comparison group. This is follow-up of a treatment trial, not a study of all pregnant people.
What did the researchers investigate?
Interpersonal therapy addresses how close relationships, conflicts and changes in life circumstances relate to mental health. The researchers examined a brief treatment programme that began before childbirth, compared with enhanced usual care.
Participants were originally randomly allocated. After birth, they completed symptom questionnaires at several points. At approximately one year, depression was also assessed in a structured interview. Such an interview determines whether specified diagnostic criteria are met and provides different information from a symptom questionnaire score alone.
What did they find?
Differences were also assessed after birth
Those allocated to therapy reported fewer depressive symptoms throughout the year after birth. The difference was therefore not measured only immediately after treatment had ended.
The results section and table report depression at one year in 4.39% of the therapy group and 12.93% of the comparison group. Rounded, that is about four versus 13 per hundred, a difference of around nine per hundred. The publication's abstract gives a slightly different decimal figure for the therapy group. This review therefore uses rounded figures from the results section.
These are differences between groups. They do not mean that treatment helped everyone or that later depression could always have been avoided with the same therapy.
How certain can we be?
Random allocation and a diagnostic interview strengthen the study. However, participants knew which care they received, and the findings come from specific services and an English-speaking sample. There were few cases of depression at one year. This makes the size of the difference less certain than percentages to two decimal places might suggest.
The comparison group received enhanced usual care. This matters: the effect was measured against that service, which may be more extensive than care offered elsewhere. The study cannot directly predict the difference in a Norwegian service organised differently.
Who do the findings apply to?
Recruitment took place at two medical centres in Denver, Colorado, USA. The original trial included 234 pregnant participants. Following four pregnancy losses, this follow-up included 230 participants, with 114 in the therapy group and 116 in the comparison group.
Participants were between 18 and 45, spoke English and had elevated depressive symptoms early enough in pregnancy to receive the treatment. People with conditions including psychosis or mania and those already receiving certain forms of psychotherapy were excluded. The result therefore concerns a selected treatment population.
What might this mean in everyday life?
The trial supports the possibility that treating depressive symptoms during pregnancy can make a difference after birth as well. It provides a reason to examine joined-up care throughout pregnancy and the postnatal period. The study says less about which approach works best when treatment begins only after a child is born.
What do we still need to know?
The therapy programme should be tested in other healthcare systems and languages. Researchers need to follow participants long enough to determine whether the difference persists and examine who still needs treatment after the programme ends.
We also need to investigate what is required to offer the sessions in routine practice. More places are not an improvement if the content or follow-up becomes inadequate. Accessibility and quality therefore need to be assessed together.
Sources
The publication covered by this review
Hankin BL, Demers CH, Grote N, Curran MC, Gallop RJ, Camille Hoffman M, Davis EP. Enduring effects of brief interpersonal therapy on depression from pregnancy through 1-year postpartum: A randomized clinical trial. Journal of mood and anxiety disorders, 2026.
Other studies and professional sources mentioned in the text
Background source: Public Health Nurse-delivered Group Cognitive Behavioural Therapy for Postpartum Depression: A Randomized Controlled Trial. 2022. Read the publication.
Previous reference on the card
Brief psychotherapy for risk of postnatal depression. Randomised study. Previous source.
Last reviewed: 30 October 2026.
Source basis: The publication's full text.
Editorial update, 1 November 2026: Language, explanations and references were reviewed. The source-review date is stated above.