Brainspotting came out of EMDR. David Grand, working with a client in 2003, noticed that when her eyes held a particular position she reached material she could not otherwise get to. The method is built on that observation.
What a session looks like
You bring something to work on and notice where you feel it in your body. The therapist then moves a pointer slowly across your field of vision, watching for a reaction — a blink, a swallow, a change in breath, a flicker you will not have noticed making. That eye position is the brainspot.
Then you hold your gaze there and pay attention to whatever comes, usually for a long time, usually with very little talking. Often with bilateral sound through headphones. The therapist mostly stays quiet and out of the way.
People frequently describe it as material arriving in an order they did not choose. That is either the method working or an hour of sustained inward attention doing what sustained inward attention does — and honestly, nobody can currently tell you which.
The theory, and what to make of it
The proposal is that eye position corresponds to subcortical activity, so a specific gaze gives access to material that talking cannot reach. That is a plausible-sounding story built on real observations about gaze and attention, and it is a long way from established.
Treat it as a working model rather than a mechanism. It does not need to be true for the method to be useful, and a practitioner who states it as settled neuroscience is overreaching.
The evidence
Thin. There are a few small trials and case series with positive results, and very little in the way of large, well-controlled work. It is younger and less studied than EMDR, which is itself less studied than trauma-focused CBT.
That is not a reason to dismiss it. It is a reason to hold expectations at the right level and to be sceptical of the enthusiastic claims that circulate about it, which run well ahead of anything demonstrated.
Who it seems to suit
People who find talking about it does not touch it, and who find the structure of exposure protocols intolerable. It asks less of you verbally than almost anything else in this field, which some people experience as an enormous relief and others find unmoored.
As with everything here: the practitioner matters more than the method. A licensed clinician doing brainspotting is doing psychotherapy that includes brainspotting. Someone who only does brainspotting has a narrower set of options when you need something else.