Children with anxiety or depression were recruited from the Child and Adolescent Anxiety and Depression Program of the Western Psychiatric Institute and Clinic, University of Pittsburgh, Pittsburgh, Pa. Children were evaluated by trained research physicians blind to the subject's clinical status and with the supervision of child psychiatrists using a modified version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children–Present and Lifetime Version (K-SADS-PL)35 with the participation of both the child and parent(s). A psychiatrist then heard the case to confirm the presence of a psychiatric disorder. Healthy control children were required to have a low familial risk for depression as defined by the absence of any current or past psychiatric disorders, no first-degree relatives with mood or psychotic disorders, no second-degree relatives with childhood-onset recurrent psychotic or bipolar depression, schizoaffective disorder, or schizophrenic disorder, and no more than 20% of second-degree relatives with a single episode of major depression. All children were screened using the vocabulary, digit span, block design, and object assembly subtests of the Wechsler Intelligence Scale for Children–Third Edition (WISC-III),36 the 12 handedness items from the Revised Physical and Neurological Examination for Soft Signs (PANESS) Inventory,37 the Tanner Scales of Pubertal Development,38 and the Screen for Child Anxiety Related Emotional Disorders (SCARED).39,40 The SCARED is a 41-item parent report and child self-report instrument. It consists of 5 factors that parallel the DSM-IV classification of anxiety disorders: somatic/panic, generalized anxiety, separation anxiety, social phobia, and school phobia. This measure was used to assess the severity of the anxiety symptoms. Exclusionary criteria for all participants included (1) a positive urine screen for cigarette, alcohol, or illicit drug use; (2) the use or presence of medication with central nervous system effects within the prior 2 weeks; (3) the presence of a significant medical or neurological illness; (4) extreme obesity (weight > 150% of the subject's ideal body weight) or growth failure (height or weight < the third percentile for the child's age); (5) an IQ lower than 80; (6) anorexia nervosa, autism, or schizophrenia by DSM-IV criteria; (7) GAD chronologically secondary to conduct disorder; (8) specific learning disabilities; (9) a current diagnosis of PTSD; or (10) any contraindication for an MRI.