AbstractObjectivesTo identify predictors and time trends over 10 years of psychiatric consultation or treatment in adolescents and young adults referring to Emergency Department (ED).MethodsReal‐world cohort data from 50,056 adolescents and young adults referring 105,596 times to ED between 2007 and 2016. We tested whether gender, age, triage code (red, yellow, green, white with decreasing severity), and referral modality predicted primary (psychiatric consultation) or secondary outcomes (anxiolytic treatment, sedative treatment, psychiatric admission), and whether these outcomes increased over the last 10 years.ResultsMean age was 19.57(SD = 2.52), female percentage was 48.77%. Overall, 6.93% underwent psychiatric consultation, treatment, or admission. Among 2,547 adolescents and young adults undergoing a psychiatric consultation, 58.07% had either yellow or red triage code, and 47.2% were brought by ambulance. Female gender predicted psychiatric consultation and anxiolytic treatment, male gender predicted sedative treatment, suggesting gender differences in help‐seeking behaviors. Older age predicted all outcomes. Severe triage presentation and being brought by ambulance increased the risk of primary and secondary outcomes. Psychiatric consultation (1.77% to 3.64%), anxiolytic (3.04% to 6.15%), or admission (0.40% to 0.98%) roughly doubled, and sedative (0.27% to 1.23%) treatment had a four‐fold increase from 2007 to 2016.ConclusionsAmong adolescents and young adults aged 15 to 24 years old ED appears to be necessary for young help‐seeking subjects given the severe presentations and the increasing number of adolescents referring to ED. More studies should assess whether ED might be helpful in detecting subjects with sub‐threshold or early psychiatric symptoms, or at risk for severe mental illness.