Conners Rating Scale (Conners 3 Guide)

The Conners Rating Scales are the criterion standard for ADHD assessment in children and adolescents (ages 6–18). Parent, teacher, and self-report versions measure inattention, hyperactivity/impulsivity, and executive function. T-score ≥65 indicates clinical concern. Conners (2008).

Looking for the Conners CPT-3? This page covers the Conners 3 Rating Scale, a questionnaire completed by parents, teachers, and youth. The Conners CPT-3 (Continuous Performance Test) is a separate computerized attention task administered directly to the patient. Both are published by MHS.

What is the Conners Rating Scale?

The Conners Rating Scales, developed by C. Keith Conners and published by Multi-Health Systems (MHS), are the most widely used standardized rating scale system for assessing ADHD and related behavioral, emotional, and academic problems in children and adolescents. The current edition, the Conners 3rd Edition (Conners 3), published in 2008, provides updated norms and expanded coverage of executive functioning and comorbid conditions.

The Conners 3 includes three parallel forms: a Parent Report (about the child, completed by parent/guardian), a Teacher Report (completed by the classroom teacher), and a Self-Report (completed by the youth, ages 8–18). Using multiple informants across settings is a key advantage, ADHD symptoms must be present in two or more settings per DSM-5-TR criteria. The Conners 3 measures six clinical scales: Inattention, Hyperactivity/Impulsivity, Learning Problems, Executive Functioning, Aggression, and Peer/Family Relations.

Conners 3 scores are reported as T-scores normalized to gender and age. A T-score of 65 or above (93rd percentile) indicates clinically elevated concerns warranting further assessment; a T-score of 70 or above (98th percentile) indicates highly elevated concerns. The Conners 3 cannot diagnose ADHD, diagnosis requires full clinical evaluation integrating rating scale data, clinical interview, history, and impairment assessment.

Conners 3 T-Score Interpreter

Enter a Conners 3 T-score for any clinical scale to interpret its clinical significance. T-scores are normalized to age and gender.

T-scores: mean = 50, SD = 10. Normalized to age and gender. Higher scores indicate more symptoms/concerns.

Conners 3 © C. Keith Conners / Multi-Health Systems (MHS). Available from mhs.com. Requires purchase and trained administrator. T-scores are age- and gender-normed. This interpreter is for educational reference only and does not constitute a diagnostic evaluation.

Conners 3 Scales & Forms

The Conners 3 uses a multi-informant approach across parent, teacher, and self-report forms. Each form includes full-length and short versions.

T-Score Reference

Conners Editions & Related Tools

A full ADHD evaluation integrates Conners 3 ratings across parent and teacher forms with a full clinical interview, developmental history, medical evaluation, and direct observation. The Conners 3 alone cannot diagnose ADHD, DSM-5-TR requires ≥6 inattention or ≥6 hyperactivity/impulsivity symptoms across two settings with onset before age 12 and significant functional impairment. For adults (≥17), ≥5 symptoms per domain is required.

ADHD Outcome Monitoring in HiBoop

Conners 3, ASRS, Vanderbilt, and behavioral health outcomes, integrated ADHD and neurodevelopmental tracking for pediatric, school, and outpatient programs.