SUDS Scale - Subjective Units of Distress Rating Tool

The Research Behind SUDS

SUDS is a clinical scaling technique, not a copyrighted questionnaire. It has been used in therapy since the 1960s and remains one of the most common ways clinicians and clients track distress.

From the Research

"Think of the worst anxiety you have ever experienced or could imagine experiencing, and assign to this the number 100. Now think of the state of being absolutely calm and call this zero."
— Mattera & Zaboski (2025), Rethinking the Subjective Units of Distress Scale, Clinical Practice 15(7), 123 — quoting Wolpe & Lazarus (1966).

Joseph Wolpe introduced SUDS in the 1960s as part of systematic desensitization, a treatment for phobias and anxiety. The idea was simple: give your distress a number from 0 to 100, then use that number to guide treatment.

Since then, SUDS has been adopted across Cognitive Behavioural Therapy (CBT), Prolonged Exposure (PE), and EMDR. It appears in clinical protocols worldwide and is listed as a self-report element in the NIMH Research Domain Criteria (RDoC).

The technique works because it is fast, requires no special equipment, and gives both therapist and client a shared language for "how bad is it right now?"

Two Common Versions

	CBT / Exposure Therapy	EMDR
Full name	Subjective Units of Distress	Subjective Units of Disturbance
Scale	0–100	0–10
Measures	Distress intensity	Memory disturbance
Common use	Hierarchy building, in-session tracking	Rating how disturbing a memory feels
Typical anchors	0 / 25 / 50 / 75 / 100	0 / 3 / 5 / 7 / 10

Some people searching for "SUDS scale" may mean the EMDR version (0–10). This tool supports both scales. Choose whichever matches your worksheet or therapist's instructions.

Validity Evidence

"Patients' reports of distress... might serve as approximate measures of actual physiological arousal."
— Marx et al. (2012), Concordance between physiological arousal and subjective distress among Vietnam combat veterans, Journal of Traumatic Stress, 25(4), 416–425.

Because SUDS is a single-item rating, standard psychometric measures like Cronbach's alpha do not apply. Instead, validation focuses on whether SUDS ratings correspond to other indicators of distress.

Physiological correspondence: In a study of Vietnam combat veterans, subjective distress ratings showed positive associations with heart rate and skin conductance during challenge tasks. This suggests SUDS can roughly reflect actual arousal, though the correspondence is approximate.
Sensitivity to change: SUDS is widely used in exposure-based CBT as an in-session rating and is sensitive to changes across exposure exercises. Many studies record SUDS at beginning, peak, and end of each session.
Clinical utility: Tanner (2012) found that global emotional SUDS ratings relate to clinician-rated functioning, though the overall validation literature remains limited.

A 2025 review argues SUDS has "significant psychometric weaknesses" and can be misinterpreted when users rate different emotions or time windows without clear prompting. This tool addresses that by asking you to specify exactly what and when you are rating.

Mattera & Zaboski (2025), Rethinking the Subjective Units of Distress Scale.

How We Built This Tool

SUDS is a clinical technique, not a fixed questionnaire with locked items. We built this tool to be method-faithful: it follows the same approach therapists use, with original wording and clear prompts.

What we kept from the original method

The 0–100 rating scale (with optional 0–10 for EMDR contexts)
Personal anchor-setting before rating, as recommended in clinical protocols
The hierarchy/fear-ladder structure used in exposure therapy planning
Beginning/peak/final tracking used in exposure homework forms

What we added

Clear measurement occasions: The tool asks you to specify whether you are rating current distress, expected distress, or memory disturbance. Research shows mixing these undermines the rating's usefulness.
Personal anchors: You define what 0, 50, and 100 mean to you. Studies recommend stable anchors for more consistent ratings.

What we do not claim

This tool does not diagnose any condition
SUDS scores do not have universal clinical cutoffs
The hierarchy is a planning artifact, not a treatment plan
We are not affiliated with Joseph Wolpe's estate or any therapy manual publisher

Sources informing this tool include Wolpe & Lazarus (1966), Bluett et al. (2013), Smits et al. (2013), Benjamin et al. (2010), Marx et al. (2012), Tanner (2012), Kiyimba & O'Reilly (2020), Kim et al. (2008), and Mattera & Zaboski (2025).

The Fear Thermometer

Standard anchor descriptions used in clinical practice to help you rate more consistently. These are examples, not diagnostic thresholds.

100 Extreme Worst distress imaginable. Feels unbearable, completely overwhelmed.

75 High Very uncomfortable. Hard to focus on anything else. Strong urge to avoid.

50 Moderate Noticeably uncomfortable. Takes effort to manage but you can still function.

25 Mild Slightly uneasy. You notice it but it passes without much effort.

0 None Completely calm and relaxed. No distress at all.

Anchor descriptions based on functional levels described in Smits et al. (2013) and common clinical handouts. These are teaching aids to help calibrate your ratings, not standardised severity bands.

SUDS vs Other Stress Measures

SUDS measures how distressed you feel right now (or how distressed you expect to feel in a given situation). It is a state measure, not a trait measure. This makes it different from questionnaires that assess stress or resilience over weeks or months.

	SUDS Scale	Perceived Stress Scale
Measures	Momentary distress level	Perceived stress over the past month
Type	State rating (right now)	Trait measure (past 30 days)
Format	Single number, rated repeatedly	10-item questionnaire
Best for	Tracking distress during exercises	Assessing overall stress levels

Interested in measuring your general stress levels? Try the Perceived Stress Test. Looking to understand how well you handle setbacks? The Bounce-Back Resilience Test measures that.

Common Questions

Use whichever scale your therapist or worksheet uses. The 0–100 scale is more common in CBT and exposure therapy research. The 0–10 scale is more common in EMDR and in some clinical settings that prefer simpler numbers. Both measure the same thing. If you have no preference, 0–100 gives you more room to make fine distinctions.

There are no universal norms for SUDS. A rating of 60 for one person is not the same as 60 for another. SUDS is designed for tracking your own distress over time or across situations, not for comparing yourself to others. Focus on your own comparisons: which situations are harder or easier for you, and how your distress shifts with practice.

In clinical psychology, SUDS stands for "Subjective Units of Distress Scale" (used in CBT and exposure therapy) while SUD in EMDR stands for "Subjective Units of Disturbance." Both use a numeric self-rating of distress or disturbance. This is different from "SUD" meaning Substance Use Disorder, which is an unrelated clinical term.

About This SUDS Tool

This tool applies the SUDS method (a single-number distress rating) with clear prompts and optional anchors. It is not a standardised diagnostic test. SUDS was developed by Joseph Wolpe in the 1960s as part of behaviour therapy.

This tool is method-faithful but uses original wording. It follows the SUDS scaling technique described in Wolpe & Lazarus (1966) and refined in subsequent clinical protocols. Our design was informed by Mattera & Zaboski's 2025 validity review, Bluett et al.'s 2013 study on distress change in prolonged exposure, Smits et al.'s 2013 anchor scheme, and Marx et al.'s 2012 work on physiological concordance. We are not affiliated with any of these authors or their institutions.

This is a self-reflection and planning tool. It helps you rate distress, build a fear hierarchy, and track changes during exercises. It does not diagnose anxiety disorders, PTSD, OCD, or any other condition. It does not measure overall symptom severity, functional impairment, or clinical risk. SUDS ratings are subjective and do not have validated diagnostic cutoffs.

If your distress is persistent, getting worse, or interfering with daily life, please speak with a mental health professional. SUDS was designed as a measurement tool used within therapy, not as a replacement for it. If you are in crisis, contact emergency services or call/text 988 (US Suicide and Crisis Lifeline).