Wender Utah Rating Scale – 25 item version (WURS-25)

The WURS-25 can be used with adults (ages 18+) seeking evaluation for ADHD, where establishing a pattern of childhood symptomatology is essential for diagnostic accuracy. Developed within a comprehensive framework that recognises the multifaceted nature of childhood ADHD presentations, the WURS-25 evaluates three distinct but interrelated dimensions of childhood difficulties:

1. Disruptive Mood/Behaviour (11 items) – assesses childhood patterns of temper dysregulation, mood instability, oppositional behaviour, and conduct difficulties, including items addressing irritability, angry outbursts, defiance, and trouble with authorities.
2. Inattentive/Hyperactive (9 items) – measures core ADHD symptoms during childhood, including concentration difficulties, distractibility, fidgetiness, impulsivity, academic underachievement, and problems with task completion and follow-through.
3. Depression/Anxiety (4 items) – evaluates childhood emotional difficulties including worry, sadness, negative self-perception, and feelings of guilt or regret that may co-occur with or complicate ADHD presentations.

For clinicians working with adults suspected of having ADHD, the WURS-25 offers several distinct advantages, particularly in addressing the diagnostic requirement for childhood onset of symptoms. Research demonstrates that retrospective assessment of childhood ADHD symptoms is crucial for accurate adult diagnosis, as many adults seeking evaluation may have limited access to childhood records or reliable informant reports. The WURS-25 provides a standardised, psychometrically sound approach to gathering this essential historical information and works well with the Adult ADHD Self-Report Scale (ASRS) which measures current symptomatology .

The WURS-25 aids significantly in assessment, differential diagnosis, and case conceptualisation. As an assessment tool, it helps identify specific patterns of childhood difficulties that may inform current presentations, facilitating a more comprehensive understanding of the client’s developmental trajectory. The enhanced scoring methodology, utilising logistic regression fitted values, enables clinicians to differentiate between ADHD and other conditions, particularly mood and anxiety disorders that may present with similar symptom profiles. The differential diagnosis capabilities calculate probabilities for ADHD versus non-clinical populations and ADHD versus depression/anxiety presentations. This statistical approach moves beyond simple cut-off scores to provide nuanced clinical information about the likelihood of childhood ADHD.

The scale’s retrospective nature requires consideration of memory limitations and potential reporting biases, but extensive validation research supports the clinical utility of the WURS-25 as a reliable and valid instrument for retrospective assessment of childhood ADHD symptoms in adult populations (Reimherr et al., 2022).

The Wender Utah Rating Scale – 25 item version (WURS-25) provides a total score and subscale scores where a higher score indicates higher reported childhood symptom severity. The normative percentile and clinical percentile are based upon the total raw score and average score (for subscales) and derived from a comprehensive study involving 485 participants (137 adults with ADHD, 228 with depression/anxiety disorders, and 120 non-clinical controls) (Reimherr et al., 2021). 

Cutoff Scores. There are two established total score cutoffs: (i) a score of 30 that best differentiates between ADHD and non-clinical controls, and (ii) a score of 46 that best differentiates between ADHD and depression/anxiety groups (Reimherr et al., 2022). Both cutoff scores are useful as clients with a valid ADHD diagnosis and primarily childhood inattentive ADHD symptoms are those most likely to be misclassified with scores below 46 (Reimherr et al., 2022), and so these cutoff scores should be used in conjunction with other information available (see the sophisticated logistic regression scoring approach outlined below).

Childhood Symptom Severity. These two cutoff scores correspond to the 94th and 99.9th normative percentiles respectively, providing an anchor for consistent percentile-based interpretation for childhood symptom severity across WURS-25 subscales:

• ≥99.9th percentile: Very High childhood symptom severity
• ≥94th percentile: High childhood symptom severity
• <94th percentile: Normal Range relative to population expectations

Subscales. The WURS-25 comprises three factors that reflect distinct but interrelated dimensions of childhood symptomatology:

1. Disruptive Mood/Behaviour (items 5, 6, 8, 10, 12, 13, 14, 18, 19, 21, 22): This subscale assesses childhood patterns of emotional dysregulation, oppositional behaviour, and conduct difficulties. This factor captures the emotional and behavioural dysregulation that often characterises childhood ADHD presentations, including difficulties with anger management, defiant behaviour, and problems with authority figures.
2. Inattentive/Hyperactive (items 1, 3, 4, 7, 15, 16, 23, 24, 25): This subscale measures core ADHD symptoms during childhood, focusing on attention difficulties, hyperactivity, and academic underachievement. This factor represents the classic ADHD symptom domains of inattention, hyperactivity, and academic difficulties that are central to diagnostic criteria.
3. Depression/Anxiety (items 2, 9, 11, 17): This subscale evaluates childhood emotional difficulties including worry, sadness, and negative self-perception that may co-occur with ADHD. This factor captures the internalising symptoms that frequently accompany childhood ADHD and are crucial for differential diagnosis.

Differential Diagnosis. The WURS-25 employs a sophisticated logistic regression scoring approach that extends beyond traditional total score interpretation to provide nuanced diagnostic information and aid in differential diagnosis. This approach generates fitted values that calculate the probability of ADHD membership relative to comparison groups. These are then converted to probabilities for presentation (although the raw fitted values are presented in a table at the end of the report for reference). This transformation yields percentage probabilities indicating the likelihood of ADHD group membership relative to the comparison population. Two distinct equations have been validated through extensive research: 

1. ADHD vs Non-Clinical Comparison. This equation differentiates individuals with ADHD from non-clinical populations. A high probability indicates a higher likelihood that the client belongs to the ADHD group as opposed to the non-clinical group.
2. ADHD vs Depression/Anxiety Comparison. This equation differentiates ADHD from mood and anxiety disorders. A high probability indicates a higher likelihood that the client belongs to the ADHD group as opposed to the depression / anxiety group. 

Overall Descriptor. The WURS-25 generates an Overall Descriptor through a sophisticated decision matrix (see Table 3 in Technical Paper) that integrates total scores and probability estimates. This system moves beyond simple cutoff scores to provide clinically meaningful descriptors:

• Very Likely ADHD: High total scores (≥46) combined with high probabilities (≥80%) for both comparisons indicate very strong evidence of childhood ADHD with clear differentiation from both non-clinical individuals and mood/anxiety disorders.
• Likely ADHD: Various combinations of elevated scores and probabilities suggesting good evidence of childhood ADHD, including high total scores with moderate clinical probabilities or moderate total scores with high probabilities across comparisons.
• Clinically Undifferentiated from Mood/Anxiety Disorders: This descriptor indicates that whilst childhood symptoms differ significantly from non-clinical individuals, they cannot be reliably distinguished from individuals with depression or anxiety disorders. This pattern suggests elevated childhood symptomatology that requires additional clinical information for differential diagnosis.
• Unlikely ADHD: Patterns suggesting limited evidence for childhood ADHD, typically involving moderate total scores with low clinical probabilities or other combinations indicating minimal ADHD likelihood.
• Very Unlikely ADHD: Low total scores combined with weak probabilities across comparisons, indicating minimal evidence of childhood ADHD symptomatology.
• Inconsistent Results: Contradictory or unusual patterns that do not fit typical profiles, such as low total scores with high clinical probabilities, requiring careful clinical interpretation and possible reassessment.

Plots. Several visualisations display the client’s scores relative to normative expectations. The Stacked Bar Chart presents the proportional contribution of each factor to the total percentile score, enabling identification of which symptom domains primarily drive elevated scores, using colour coding with elevated ranges in orange (High) and very elevated ranges in red (Very High). The Horizontal Distribution Chart overlays the client’s total score on bell curve distributions representing different populations: non-clinical (blue curves) and ADHD (red curves). The separation between distributions illustrates the degree of differentiation possible, whilst the client’s position relative to each curve provides intuitive understanding of their symptom pattern. Percentile markers (25th, 75th) and mean lines help contextualise the client’s position within each distribution. Individual horizontal charts for each subscale follow the same format, enabling detailed analysis of specific symptom domains and helping identify whether elevations are broad-based or concentrated in particular areas. When multiple administrations are available, the WURS-25 generates a line graph displaying total scores across assessment points, enabling tracking of symptom reporting consistency over time.

The WURS-25 was developed through systematic item reduction from the original 61-item Wender Utah Rating Scale, selecting items that demonstrated the greatest discriminative power between adults with ADHD and control groups whilst maintaining clinical utility (Ward et al., 1993).

Confirmatory factor analysis has consistently supported a three-factor structure across multiple populations and cultural contexts. Brevik et al. (2020) confirmed the dimensional validity established by Caci et al. (2010), McCann et al. (2000), and Stanton and Watson (2016). The three factors represent: (1) Disruptive Mood/Behaviour, assessing childhood patterns of temper dysregulation and oppositional behaviour; (2) Inattentive/Hyperactive, measuring core ADHD symptoms including concentration difficulties and academic underachievement; and (3) Depression/Anxiety, evaluating childhood emotional difficulties including worry and negative self-perception. Recent factor analytic work by Reimherr et al. (2021) using both the WURS-25 and full WURS confirmed this structure with substantial variance explained by the three factors.

The internal consistency of the WURS-25 has been demonstrated to be excellent across multiple studies. Kouros, et al. (2018) reported Cronbach’s alpha coefficients of 0.94 for the total scale in their Swedish validation study, with individual factor reliabilities ranging from 0.81 to 0.94. Similarly, Brevik et al. (2020) found excellent internal consistency with Cronbach’s alpha of 0.952 for the full WURS and adequate to good reliabilities for individual factors.

Construct validity is supported by theoretically consistent relationships with objective measures of attention and cognitive performance. Mackin and Horner (2005) demonstrated that higher WURS-25 scores were significantly associated with poorer performance on the WAIS-R Digit Symbol subtest (r = -0.691, p < 0.05), with digit symbol performance accounting for 59% of the variance in WURS scores. This relationship between retrospective symptom reports and objective performance measures strengthens confidence in the scale’s validity for identifying individuals with genuine childhood ADHD histories.

The discriminant validity of the WURS-25 has been extensively examined through its ability to differentiate between diagnostic groups. Reimherr et al. (2021) demonstrated clear separation between ADHD samples (M = 51.47, SD = 15.7), non-clinical controls (M = 14.51, SD = 9.99), and clinical controls with depression/anxiety (M = 29.2, SD = 18.0). The WURS-25 can provide diagnostic sophistication from its use of logistic regression analysis to generate fitted values that calculate the probability of ADHD membership relative to comparison groups. Two distinct equations have been validated: 

1. ADHD vs Non-Clinical Comparison: Fitted Value (Non-Clinical) = -5.84 + (Disruptive Mood/Behaviour × 1.83) + (Inattentive/Hyperactive × 2.44) + (Depression/Anxiety × 0.16), where the large coefficient for the Inattentive/Hyperactive factor (2.44) indicates its primary importance in distinguishing ADHD from typical development; and 
2. ADHD vs Depression/Anxiety Comparison: Fitted Value (Clinical) = -3.90 + (Disruptive Mood/Behaviour × 0.73) + (Inattentive/Hyperactive × 2.51) – (Depression/Anxiety × 1.24), where the Depression/Anxiety factor is subtracted, reflecting that high scores on this dimension reduce the probability of ADHD when differentiating from mood/anxiety disorders. 

The fitted values represent log odds and are converted to probabilities using the logistic function, yielding percentage probabilities indicating the likelihood of ADHD group membership. This methodology achieved area under the curve (AUC) values of 0.924 for ADHD versus depression/anxiety and 0.982 for ADHD versus non-clinical controls, with sensitivity improved by 10% compared to using total scores alone.

Cross-cultural validation studies have supported the generalisability of the WURS-25’s psychometric properties across diverse populations. The scale has been translated into multiple languages and validated in Swedish (Kouros et al., 2018), French (Caci et al., 2010), Italian (Fossati et al., 2001), Spanish (Rodríguez-Jiménez et al., 2001), German (Retz-Junginger et al., 2003), Finnish (Kivisaari et al., 2012), and Turkish (Oncü & Sentürk, 2005) populations, consistently demonstrating robust construct validity across cultural boundaries.

Normative data for percentile conversion have been established from the Reimherr et al. (2021) study involving 485 participants, including 137 adults with ADHD, 228 with depression/anxiety disorders, and 120 non-clinical controls. The established total score cut-offs of 30 and 46 correspond to the 94th and 99.9th normative percentiles respectively, providing the foundation for consistent percentile-based interpretation. Using the means and standard deviations outlined in Table 1 of the manual (Reimherr et al., 2022), raw scores are converted to z-scores and percentiles using normative tables outlined below, enabling standardised classification of childhood symptom severity across both normative and clinical populations.

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