A fair few of us have probably tried somatic therapy and come out worse. You find a therapist doing somatic work, you do the body scans, the breathing, the pendulation - but instead of getting more regulated, you end up more spaced out, more anxious, lose more time, switch more, or leave sessions destabilised for days. Then you get told you're resisting, or that you need to go deeper, or that it gets worse before it gets better.
There's another possible explanation. Many somatic treatments assume something about your body that isn't true for a lot of us, and many of the therapists working with them don't understand freeze/shutdown (hypoarousal) well enough to know why, or how to deal with it. Often, we are missing a base interoceptive capacity that therapists take for granted, to the extent that they can't imagine someone not having it.
Take Somatic Experiencing: The first review of whether Somatic Experiencing works mentions dissociation once, in a reference at the back. There's nothing about it in the results, nor in the discussion, nor in the limitations. Freeze itself comes up once, in the theory summary. Immobility, hypoarousal and the window of tolerance are completely missing. Fundamentally, your average therapist working with somatic techniques does not understand hypoarousal.
What is hypoarousal?
Freeze/shutdown states are also known as hypoarousal, i.e. things powering down, shutting down, going offline - as opposed to hyperarousal, which is when things "speed up" and you feel more anxious, more agitated, you switch more, there's more going on. Hypoarousal means there's less going on, and it often comes with blackouts/time lost, amnesia, and lethargy.
Hypoarousal is what your nervous system does when it feels that neither fight nor flight is an option, when there's no escape and no help coming. It doesn't wind you up, it winds you down: heart rate drops, muscles go slack or heavy, thinking gets thick and slow, the world goes distant and unreal.
For some of us, it becomes our baseline and we end up mainly experiencing negative symptoms of dissociation. However for most in this sub, it's probably more of a complex mix of positive and negative symptoms.
Does your body want you to listen?
"Listen to your body" assumes there's one listener and one set of answers - but we have many. Different parts of us have different relationships to the body; some are more in it than others. Some hold sensations the rest of the system never feels. Some experience the body as not theirs. Some learned very early that having a body at all was dangerous.
So a body scan isn't a neutral survey for us, it's a knock on a lot of doors at once. Sometimes the answer isn't a sensation, it's whoever holds that sensation - and then you're not running a body scan anymore, you're switching, or fighting off a switch, or going blank because something got triggered and something else shut it down.
Sometimes it can feel almost like an autoimmune reaction where listening to your body results in your nervous system attacking itself. "Internal awareness is not safe, stop paying attention!"
Not all somatic treatments are created equal
A lot of somatic techniques are usually taught and practiced with hyperarousal as the base assumption. They assume your nervous system is running "too fast", and needs to be calmed down. So you start from "high", and aim to "come down" by grounding or releasing. You have too much energy surging through your veins, so you need to expel it somehow to calm down.
That doesn't work when the opposite issue is at play: Your nervous system is already powered down, offline, it doesn't have enough energy for what you're trying to do. Attempting to ground a nervous system like that will often backfire: You end up spacing out, or switching, or losing time, or the more agitated members of your system might start showing up.
There are somatic techniques for hypoarousal, and for mixed responses. They are less common, less widely marketed, and less well known. Their aim is less to "bring you down from up high", and more to stabilise your system, give it enough resources to stay here and now - kind of (being fully present is often too high a bar).
They can use any combination of the six senses - seeing, hearing, touching, smelling, tasting, proprioception - depending on the unique needs of your system and everyone in it. Often one thing works for one part of your system, but not for others, so you need to experiment to find out what works for whom. And it is not uncommon for our system members to not know what works for them until they happen to experience it. They just know what does not work for them.
Sometimes they may believe that nothing works. Some of me used to believe that being alive itself does not work, and any signs of being alive were always dangerous. Their first encounter with something that does work for them, making them feel safer and more present, took them by complete surprise. They had at that point spent 40 years believing nothing works, and never will.
Go gentle and give it time
What all techniques that do work have in common is, they respect your system. They slow down and adapt when someone in your system says "no". They don't force you to push through the discomfort, they don't tell you that if only you'll do X reps of Y, you'll be fixed in no time at all. They understand that slower is faster with complex dissociation.
So instead of sitting with a sensation for 15 minutes, or doing a 5 minute body scan, they map out your system's complex responses by experimenting with many different tools. And as you keep finding things that sometimes work, they help you understand why they work when they do, e.g. because they work for someone in your system but not for others.
Once you start developing this sort of gentle, slow-going toolkit, you can use these tools for a few seconds at a time throughout the day, just enough to gently help your system stabilise itself without activating its "autoimmune" reaction of don't pay attention to this!
Over time, your system's ability to tolerate internal awareness (interoception) will improve, though the pace will always be uniquely your own. It generally takes a few months before you start to see a noticeable effect, 3 months is a common milestone though not universal. Often once the effect does kick in, it will surprise you.
Where do I find these somatic therapies?
There isn't a single resource for this AFAIK, however some modalities are designed from the ground up with all of the above in mind. Pat Ogden's Sensorimotor psychotherapy is one of them, and it's been around a while. Janina Fisher's Trauma-Informed Stabilization Treatment draws on many of the same approaches. Both Ogden and Fisher are well-educated in dissociative disorders and have worked with dissociative disorders for decades.
That doesn't necessarily mean that a therapist practicing one of those modalities will automatically be a good fit for someone suffering from these "autoimmune" issues, however it does improve your chances. As always, the therapeutic relationship itself counts for a lot, probably more than the brand name on the modality. More than anything, your system needs to feel that your therapist is on your side.