IFS is a form of psychotherapy founded by Richard Schwartz in the 1980s. Clinical studies have shown its effectiveness and it is considered an evidence-based therapy. IFS is:
Parts-based – it recognises that we all consist of different parts or sub-personalities: these appear in response to trauma that we may experience in life, especially at a young age
A systems therapy – as in systemic family therapy, out of which IFS developed and for which it is named, individual parts are seen within the context of their relations, within the client’s whole system (ie the ‘internal family’)
Non-pathologising – all protective parts, even ones in extreme or destructive positions, are fundamentally well-intentioned as they trying their best to protect the vulnerable traumatised parts; when actively engaged with, they start to relax and look at things in a different way
A constraint/release model – traumatised parts and parts that had to take on difficult protective roles can be freed from the heavy and unnecessary burdens they carry, discovering more enjoyable and creative ways to express themselves
There is a wealth of detailed information about IFS on the web. Try for instance:
YouTube has a number of videos, such as this interview with Richard Schwartz:
And this podcast is an interview with Richard Schwartz: