SWAN: Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale
An 18-item dimensional rating scale assessing ADHD symptoms in the context of normal behavioural variation. Rated on a bipolar scale from far below average to far above average. Appropriate for children, adolescents, and adults; available in parent, teacher, and self-report formats.
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. 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 the SWAN Measures
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.
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.
Scoring
Total score range: -54 to +54 Subscale score range: -27 to +27
Mean scores below -1.0 per item are considered clinically elevated. The dimensional nature of the SWAN allows for continuous score analysis rather than categorical cutoffs, which is advantageous in research contexts.
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 (Vajsz et al., 2024)
Multi-informant administration is recommended for clinical assessment of ADHD in children.
Psychometric Properties
- Good internal consistency for both subscales (Cronbach's α ≈ 0.88–0.96)
- Confirmatory factor analysis supports the two-factor (inattention/hyperactivity-impulsivity) structure
- Strong convergent validity with the Conners Rating Scales and ADHD Rating Scale-IV
- The dimensional structure is consistent across gender and informant (Trejo et al., 2023)
- Validated in German (Schulz-Zhecheva et al., 2017), Chinese, and Hungarian samples
Clinical Applications
The SWAN is appropriate for:
- Diagnostic evaluation: As a complement to clinical interview and cognitive assessment for ADHD
- Treatment monitoring: Sensitive to medication and behavioural intervention effects
- Research: Dimensional scoring facilitates correlation and regression analyses
- Adult ADHD: The self-report version provides developmentally appropriate assessment for adults
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
References
- Swanson JM, Schuck S, Porter MM, et al. (2012). Categorical and dimensional definitions and evaluations of symptoms of ADHD: History of the SNAP and the SWAN Rating Scales. International Journal of Educational and Psychological Assessment, 10(1), 51–70.
- Schulz-Zhecheva Y, Voelkle M, Beauducel A, et al. (2017). ADHD Traits in German School-Aged Children: Validation of the German Strengths and Weaknesses of ADHS Symptoms and Normal Behavior (SWAN-DE) Scale. Journal of Attention Disorders, 21(4), 327–339. PMID: 28043193
- Trejo S, Andaverde-Vega AA, Villalobos-Gallegos L, et al. (2023). Factor structure, measurement invariance, and scoring practices of the strengths and weaknesses of ADHD-symptoms and normal behavior. Psychological Assessment, 35(3), 286–296. PMID: 36455026
- Vajsz K, Paulina LR, Trejo S, et al. (2024). 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. Frontiers in Psychiatry, 15, 1378690. PMID: 39026526
Frequently Asked Questions
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.
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