SWAN: Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale
The SWAN (Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale) is an 18-item dimensional rating scale that measures ADHD symptoms against the full range of normal behaviour, rating each DSM symptom from far below to far above average. It is used with children, adolescents and adults in parent, teacher and self-report formats.
For professional reference, research, and education only. Not for diagnosis or medical advice.
About the SWAN
The Strengths and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN) scale was developed by James Swanson and colleagues as a dimensional alternative to traditional ADHD symptom severity scales such as the SNAP-IV [1]. Unlike most ADHD measures, which ask only about symptom presence or frequency, the SWAN frames each item relative to the full range of typical behavior, capturing both strengths and weaknesses.
This approach reflects a neurodevelopmental and dimensional conceptualization of ADHD: symptoms exist on a continuum with normal behavior, and both below-average and above-average functioning on attention and activity regulation have clinical relevance.
What does the SWAN measure?
The SWAN contains 18 items corresponding to the 18 DSM diagnostic criteria for ADHD, grouped into two subscales:
Inattention subscale (9 items) Covers attention regulation, task persistence, organization, listening, and following instructions.
Hyperactivity-Impulsivity subscale (9 items) Covers activity level, ability to sit still, impulse control, waiting, and turn-taking.
How do you give the SWAN?
A parent, teacher or the person themselves rates each of the 18 items relative to the full range of typical behaviour, from far below to far above average. Brief instructions on the bipolar format are recommended, because raters are used to symptom-only scales.
Format versions
The SWAN is available in:
- Parent-report: For children and adolescents (approximately ages 5–18)
- Teacher-report: Cross-setting assessment for school-age children
- Self-report: Validated for adolescents and adults [5]
Multi-informant administration is recommended for clinical assessment of ADHD in children.
Rating format
Each item is rated on a 7-point bipolar scale:
| Score | Anchor |
|---|---|
| +3 | Far above average |
| +2 | Above average |
| +1 | Slightly above average |
| 0 | Average |
| -1 | Slightly below average |
| -2 | Below average |
| -3 | Far below average |
Lower (more negative) scores indicate greater ADHD-related impairment. Higher (positive) scores reflect strength or above-average regulation.
How do you score and interpret the SWAN?
Total score range: -54 to +54 Subscale score range: -27 to +27
A per-item mean below -1.0 is a commonly used convention for a clinically elevated score; it is not a validated cutoff, and the cited sources do not define clinical bands. A study of 650 parents found that averaged SWAN scores came closer to the underlying ADHD trait when read against sex-specific percentiles [3].
The dimensional nature of the SWAN allows for continuous score analysis rather than categorical cutoffs, which is advantageous in research contexts.
Psychometric properties
- Distribution: The SWAN was designed to correct the skewed distribution of the SNAP by rewording items and widening the rating range, reducing over-identification of extreme cases [1]. Scores in validation samples are close to normally distributed.
- Preschool, English and Spanish [2]: Parent ratings showed high internal consistency, moderate three-month test-retest reliability, and adequate convergent and discriminant validity with the Strengths and Difficulties Questionnaire.
- Germany [4]: In 343 children from the general population and 62 children with ADHD aged 8–18, the SWAN-DE showed good to excellent reliability, factorial validity and high diagnostic utility in distinguishing children with ADHD from controls.
- Mexico [3]: In 650 parents of junior high school students, a bifactor model (one general ADHD factor plus inattention and hyperactivity-impulsivity factors) fitted best and was invariant across sex and cultural background, but only the general factor was reliable enough for scoring.
- Self-report, Hungary [5]: In 664 young women (mean age 20), the self-report version showed a bifactor structure with good general-factor reliability (omega-h 0.87), normally distributed scores and a strong correlation with the SDQ Hyperactivity subscale.
Limitations
- Not a diagnosis. The SWAN quantifies ADHD-related traits; diagnosis needs a full clinical evaluation with history and multiple informants.
- No validated cutoff. It is designed for dimensional use; the per-item mean of -1.0 is a convention, and sex-specific percentiles are preferable where norms exist.
- Subscale scores. Factor analyses suggest the general (total) score is more reliable than separate inattention and hyperactivity-impulsivity scores.
- Scoring direction varies. Some versions score symptoms as positive and strengths as negative; confirm the direction before comparing scores.
- Self-report evidence is limited. The self-report validation used a non-clinical sample of young women.
How is the SWAN used in practice?
The SWAN is appropriate for:
- Diagnostic evaluation: As a complement to clinical interview and cognitive assessment for ADHD, alongside scales such as the Vanderbilt
- Treatment monitoring: Repeat ratings can track change in attention and activity regulation over time
- Research: Dimensional scoring facilitates correlation and regression analyses
- Older adolescents and adults: The self-report version has been validated in adolescents and young adults [5]
Clinical considerations
- The SWAN's bipolar format may be unfamiliar to some raters; brief instructions on the scale's meaning are recommended
- Positive scores on strength items can inform strengths-based treatment planning
- As with all ADHD measures, SWAN results should be interpreted alongside functional history and direct observation
For individuals: This page is a clinical reference, not a diagnostic tool. If you have concerns about your own symptoms, bring this information to a qualified mental health professional.
Related
Billing
In the US, the SWAN: Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale is usually billed under these CPT codes. Payer rules vary.
Assessments
- Aberrant Behavior Checklist
- ADHD Clinical Outcome Scale, Self-Report (ACOS-SR)
- ADHD Test for Adults (ASRS-v1.1)
- AQ Scoring & Cutoffs · Autism Spectrum Quotient
- Autism Spectrum Quotient, Brief (AQ-10)
- CARS-2 (Childhood Autism Rating Scale)
Dot size shows how strongly each scale's condition is linked to this one in HiBoop's co-occurrence map.
FAQ
How is the SWAN scored, and which direction indicates more ADHD symptoms?
Each of the 18 items is rated on a 7-point bipolar scale from +3 (far above average) to –3 (far below average). Scores are summed for a total range of –54 to +54 and for each subscale from –27 to +27. Lower (more negative) scores indicate greater ADHD-related difficulty, which is the opposite of most symptom rating scales. A per-item mean below –1.0 is a commonly used clinical convention for a clinically elevated score.
Is the SWAN self-report or rater-administered?
The SWAN is available in parent-report, teacher-report, and self-report formats. Parent and teacher versions are most established for children and adolescents. A self-report version has been validated for adolescents and adults, with good psychometric properties confirmed in the Vajsz et al. (2024) Hungarian sample.
Can the SWAN diagnose ADHD?
No. The SWAN is a rating scale that quantifies the severity and dimensional profile of ADHD-related symptoms; it cannot establish a diagnosis on its own. Diagnosis of ADHD requires a comprehensive clinical evaluation incorporating developmental history, direct observation, and information from multiple informants, with the SWAN used as a supporting measure.
How does the SWAN differ from the SNAP rating scale?
The SNAP (Swanson, Nolan, and Pelham) scale rates only the below-average (symptomatic) end of the behavioural continuum, producing a skewed distribution that can over-identify extreme cases. The SWAN was developed to correct this by extending the rating scale to include above-average functioning, producing a more normally distributed score distribution and capturing the full dimensional range of attention and activity regulation.
References
- 1.Swanson JM, Schuck S, Porter MM, et al. Categorical and dimensional definitions and evaluations of symptoms of ADHD: history of the SNAP and the SWAN rating scales. Int J Educ Psychol Assess. 2012;10(1):51-70.
- 2.Lakes KD, Swanson JM, Riggs M. The reliability and validity of the English and Spanish Strengths and Weaknesses of ADHD and Normal behavior rating scales in a preschool sample: continuum measures of hyperactivity and inattention. J Atten Disord. 2012;16(6):510-516.
- 3.Trejo S, Andaverde-Vega AA, Villalobos-Gallegos L, Swanson JM, Salum GA. Factor structure, measurement invariance, and scoring practices of the strengths and weaknesses of ADHD-symptoms and normal behavior. Psychol Assess. 2023;35(3):269-279.
- 4.Schulz-Zhecheva Y, Voelkle M, Beauducel A, Buch N, Fleischhaker C, Bender S, Saville CWN, Biscaldi M, Klein C. ADHD Traits in German School-Aged Children: Validation of the German Strengths and Weaknesses of ADHS Symptoms and Normal Behavior (SWAN-DE) Scale. J Atten Disord. 2019;23(6):553-562.
- 5.Vajsz K, Paulina LR, Trejo S, Andaverde-Vega AA, Swanson JM, Miklósi M. Psychometric properties of the self-report version of the Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale in a sample of Hungarian adolescents and young adults. Front Psychiatry. 2024;15:1330716.
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