Is caregiver-adolescent disagreement due to differences in thresholds for reporting manic symptoms?

INTRODUCTION: Cross-informant disagreement is common and results in different interpretations of a youth's behavior. Theoretical explanations for discrepancies typically rely on scale level analyses. This article explores whether caregivers and adolescents differ in when they notice and report symptoms of youth mania depending on the severity of overall manic disturbance.
METHOD: Participants were 459 adolescent-caregiver pairs recruited at either a community mental health center or an academic medical center. Adolescents were most likely to have a primary diagnosis of unipolar depression (37%) or attention-deficit/hyperactivity disorder/disruptive behavior disorder (36%). Nineteen percent of adolescents received a bipolar spectrum disorder diagnosis (4% bipolar I and 15% bipolar II, cyclothymia, or bipolar not otherwise specificed). Caregivers were primarily biological mothers (74%) or grandparents (8%). Adolescents and caregivers independently completed the Mood Disorder Questionnaire (MDQ) about the adolescent.
RESULTS: Item response theory analyses of the entire sample indicated that in general, both caregivers and adolescents reserved endorsement of mania symptoms for the most severely ill half of participants. Comparisons of caregiver and adolescent report of symptoms on the MDQ indicated two significant differences. Caregivers were more likely to report irritability at significantly lower severity of mania than adolescents. Adolescents endorsed only increased energy or hyperactivity at lower severities than caregivers.
CONCLUSIONS: Adolescents and caregivers will have different concerns and might report different symptoms consistent with whom the symptom impacts first. Caregivers are more likely to report behaviors such as irritability, whereas adolescents are more likely to report subjective feelings such as feeling more energetic or more hyperactive.