Sondeijker, F.E.P.L.

problem behavior cortisol anxiety study level adolescent cortisol levels sample activity association children scale measure hpa-axi child score disorder hpa-axis activity psychiatry effect gender population anxiety problems cd problems hrv lf analyses journal supine result individual future behavior problems research model depression trail factor parent internalizing problems class symptom vagal vagal activity reactivity adolescent psychiatry verhulst child behavior checklist interaction posture raine heart system conduct disorder supine posture american academy heart rate stress predictor externalizing internalizing regression analyses conduct difference adh problems american theory finding questionnaire regression table fl exibility stage psychopathology population sample chapter variable od problems group academy