1. Scale Introduction

The SNAP-IV Rating Scale (Swanson, Nolan, and Pelham Rating Scale-IV) is a standardized tool widely used internationally for the screening, auxiliary diagnosis, and treatment efficacy evaluation of Attention Deficit Hyperactivity Disorder (ADHD) in children. Its development and revision have always been centered around authoritative diagnostic criteria, combining scientific rigor, practicality, and specificity, and it is extensively adopted by major hospitals and research institutions.

The scale originated from the early SNAP scale. The most commonly used version currently is the SNAP-IV version, compiled based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). It mainly comes in two versions: an 18-item and a 26-item version, where the 26-item version includes items related to Oppositional Defiant Disorder. It has subsequently been gradually aligned with the DSM-5 diagnostic criteria, further enhancing its clinical adaptability.

It supports parent ratings (home behavior), teacher ratings (school behavior), and self-reports for older children (12 years and older), covering the child's main activity scenarios and reducing the limitations of a single observer.

The core feature of the SNAP-IV scale is its high degree of alignment with ADHD diagnostic criteria. Items are designed strictly according to the 18 core symptoms of ADHD in DSM-IV (9 items for inattention, 9 items for hyperactivity/impulsivity), while also covering items related to Oppositional Defiant Disorder and conduct issues. Each symptom item is rated based on frequency of occurrence. The scoring is simple, clear, and concise, facilitating rapid screening and assessment of symptom severity.

Test Dimensions:

• Inattention: 9 items assessing whether the child is easily distracted, misplaces things, or has difficulty sustaining attention, etc.
• Hyperactivity/Impulsivity: 9 items assessing whether the child fidgets, runs excessively, has difficulty playing quietly, or interrupts impulsively, etc.
• Oppositional Defiance: 8 items assessing whether the child exhibits behaviors such as defying authority, being easily angered, or deliberately annoying others, etc.

Applicable Age Range

• Core applicable range: Children and adolescents aged 4 to 18 years.
• Preschool children: Completed by parents or kindergarten teachers, focusing on observing behavior during play and daily activities.
• Adolescents: Self-report scales can be combined to improve assessment accuracy.

Administration Recommendations

• Dual-source assessment: It is recommended to collect ratings from both parents and teachers simultaneously. Children face different demands at home and school, and their behavior may show significant differences (e.g., some children may not show obvious symptoms at school due to structured management but are prominent at home, or vice versa).
• Comprehensive judgment: If there is a significant discrepancy between parent and teacher ratings, clinicians need to conduct further interviews to understand specific contextual factors and avoid misjudgment.

2. Scores and Ratings

Reference source: Introduction to the Chinese version of this scale and test link address https://toolonline.net/SNAP-IV