Diagnose ADHD, predominantly inattentive presentation, based on the elevated teacher Vanderbilt scores confirming cross-setting impairment.

ADHD requires impairment across two or more settings. An elevated teacher rating with normal parent ratings does not meet DSM-5 criteria without further clarification.

Investigate the informant discordance by screening for learning disabilities, anxiety, sensory deficits, and environmental factors that may explain school-specific inattention.

Informant discordance is a clinical finding that requires interpretation. Possibilities include: a learning disability causing school-specific inattention, anxiety that manifests in the classroom but not at home, vision or hearing problems, a classroom environment mismatch, or the parent underreporting symptoms. ADHD requires symptoms in two or more settings — a single elevated teacher rating without cross-setting impairment does not meet criteria. The PMHNP should gather additional data — classroom observation reports, academic testing, sensory screening, and direct clinical assessment — before diagnosing.

Diagnose anxiety disorder, as informant discordance suggests the child is internalizing symptoms and masking difficulties at home.

Jumping to an anxiety diagnosis based on informant discordance alone is premature. The discordance itself is the clinical data that requires exploration.

Average the parent and teacher Vanderbilt scores to produce a composite result and use the combined score to determine diagnosis.

Averaging discordant ratings eliminates the clinically meaningful information contained in the discordance itself. The discrepancy is the finding to investigate.