Internal Family Systems: what the research says

IFS has only a few small, early studies, so the evidence for low mood, trauma and long-term pain is limited. Talking therapies such as CBT have more evidence for low mood and worry.

What a session is

A talking therapy that sees the mind as made up of different 'parts', such as a critical part or a hurt part. With a therapist, you get to know these parts with curiosity and calm.

What the research says

• Low mood: Only small, early studies so far. In a 2017 pilot trial of 37 women at university with depression, symptoms fell about as much with IFS as with usual therapy (CBT or interpersonal therapy), but the trial was too small to show a difference between them. In a 2013 trial of 79 people with rheumatoid arthritis, those who had IFS reported fewer symptoms of depression a year after it ended than those who were sent information by post. A 2025 review called IFS promising but said the research is still limited. If low mood lasts 2 weeks or more, see a GP; talking therapies such as CBT have good evidence. Limited evidence · Journal of Marital and Family Therapy, 2017 · Journal of Rheumatology, 2013 · Clinical Psychologist, 2025 · NHS, 2026
• Trauma and PTSD: Only small, early studies so far. In a 2026 trial of 60 adults with PTSD, symptoms fell about as much with online IFS groups as with a nature-based group programme. Smaller studies without a comparison group also found that symptoms fell. UK guidance recommends trauma-focused CBT or EMDR for PTSD. Limited evidence · Psychological Trauma, 2026 · Clinical Psychologist, 2025 · NICE, 2018 · NHS, 2026
• Worry and anxiety: No study has focused on worry or anxiety. The 2013 trial in people with rheumatoid arthritis also measured anxiety and found no lasting change. For worry that affects daily life, a GP usually offers CBT first. No good evidence yet · Journal of Rheumatology, 2013 · NHS, 2024
• Long-term pain: One small trial so far. In the 2013 trial of 79 people with rheumatoid arthritis, those who had 9 months of IFS reported less pain and could do more day to day than those who were sent information by post. Joint pain was still lower a year later, but the disease itself did not change. More trials are needed. Limited evidence · Journal of Rheumatology, 2013 · Clinical Psychologist, 2025
• Stress, sleep, menopause and grief: Not studied in the sources we use. No good evidence yet

More on each need: Lift your mood · Feel calmer

Is it safe?

Talking about painful experiences can be upsetting at first, so tell your therapist if it is. If you have an eating disorder, bipolar disorder, a personality disorder or psychosis, talk to your GP first. NICE, 2022 · NHS, 2025

Sessions on Sissoo complement medical care and never replace it. Please don’t stop or change any treatment without talking to your doctor. If you feel very low or think about ending your life, call your local emergency number now.

Checked 9 November 2026. Next check by May 2027. How we rate the evidence.