SUDS scale: subjective units of distress, explained

SUDS stands for Subjective Units of Distress (or Disturbance): a simple self-rating scale, usually 0 to 10, for how intense your distress feels right now. Zero means completely calm; the top means the worst distress you can imagine. Psychologist Joseph Wolpe introduced it in 1969; EMDR therapists use it to track a memory’s emotional charge.

Where does the SUDS scale come from?

Behavioral psychologist Joseph Wolpe introduced the scale in his 1969 book The Practice of Behavior Therapy (Pergamon Press), originally running 0 to 100. His instructions were direct: picture the calmest you could feel and call it zero. Picture the worst anxiety you could imagine and call it 100, then rate where you are right now. Wolpe designed it for exposure-based behavior therapy. A shorter 0-to-10 version, easier to use mid-session, is what most clinicians use today.

How does EMDR use the SUDS scale?

Per EMDRIA’s walkthrough of the eight phases of EMDR therapy, a SUDS rating does two jobs. In the assessment phase, you rate your distress about a target memory before any processing starts, which sets a baseline. In the desensitization phase, your therapist checks your SUDS after each set of bilateral stimulation: the eye movements, tones, or taps at the center of EMDR. They continue until it drops to 0 or 1.

A 2008 study in the Journal of EMDR Practice and Research found that clients’ starting SUDS score correlated with their pretreatment anxiety and distress. Their ending SUDS score also tracked with independently rated improvement — evidence the number reflects something real, at least across a group.

How do you use it on your own?

You don’t need a therapist to use the scale. Before trying a calming technique, pause and ask: on a 0-to-10 scale, how distressed do I feel right now? Try the technique, whether that’s grounding, slow breathing, or a round of self-guided bilateral stimulation, then rate again. The gap between your two numbers is a rough, honest gauge of whether it helped.

The same habit works if you’re practicing bilateral stimulation on your own time with EmEase, a self-guided EMDR app, at app.emease.com. Rate before, rate after, and let the number guide you rather than a guess.

Is the SUDS scale scientifically reliable?

Worth knowing, in the spirit of honesty over hype: a 2025 peer-reviewed review in Clinics and Practice found real weaknesses in the SUDS. It flagged vague instructions and inconsistent use across studies, and cautioned against treating any single score as a precise measurement. Used as a rough personal check-in, it still earns its keep. Read it as a trend over time, not as one exact number. If your number regularly sits high and won’t come down on its own, that pattern is worth bringing to a professional. See is self-guided EMDR safe for where that line sits.