PHQ-9 modified for adolescents (PHQ-9A/PHQ-A), which uses developmentally appropriate language to capture depression presenting as irritability, boredom, and withdrawal.

The PHQ-A/PHQ-9A is recommended for depression screening in adolescents ages 12-17. This child's presentation — boredom, withdrawal, hypersomnia, weight gain, declining grades — is a classic adolescent depression pattern where sadness may not be the chief complaint. In this age group, depression often presents as irritability, boredom, and withdrawal rather than overt sadness. Additionally, the PMHNP should screen for bullying, academic stressors, social media-related distress, and substance use. Assess sleep quality — hypersomnia in an adolescent can reflect depression, but also insufficient sleep from late-night screen use with compensatory oversleeping.

PHQ-9, as it is the standard depression screener validated across populations and would capture the core depressive symptoms described in this presentation.

The PHQ-9 is used in adolescents in some settings, but an adolescent-adapted version (PHQ-A/PHQ-9A) is preferred as it includes developmentally appropriate language and context.

CDI-2 (Children's Depression Inventory), which is considered the gold standard for childhood depression and covers the full 7-17 age range with validated norms.

The CDI-2 is validated for ages 7-17 and is a reasonable tool, but the PHQ-A is more widely used in clinical practice and aligns with adult PHQ-9 scoring that the patient will encounter in future care.

Beck Depression Inventory, a well-validated and widely researched instrument that provides reliable severity scoring to guide treatment decision-making.

The BDI was developed for adults and is not the optimal tool for a 12-year-old. Adolescent-specific tools use developmentally appropriate language.