Transdiagnostic Internet-delivered REBT Intervention for Adolescents' Internalizing Problems

Inclusion Criteria: * Age between 12 and 15 years * A principal diagnosis of Social Anxiety Disorder, Generalized Anxiety Disorder, Panic Disorder, Persistent Depressive Disorder, or Major Depressive Disorder as defined by DSM-5 (APA, 2013) * Not currently following another treatment (psychotherapy, pharmacological treatment); * Internet access * Ability to read and write Romanian Exclusion Criteria: * Suicidal ideation * Severe depression * Any physical and mental health acute problem that requires hospitalization * Diagnosed with autism spectrum disorder, psychosis, bipolar disorder or mental disability