Structural imaging was performed at the McLean Hospital Brain Imaging Center on a 1.5 Tesla Scanner (Signa; GE Medical Systems, Milwaukee, WI).

Measures of current psychopathology were obtained using the Mania Rating Scale (MRS) (Young et al. 1978) and Global Assessment of Functioning scale (GAF

MeasureID: MRS
MeasureDescription: Mania Rating Scale (MRS)
MeasureDomain: current psychopathology
MeasureReference: Young et al. 1978

MeasureID: GAF
MeasureDescription: Global Assessment of Functioning scale (GAF)
MeasureDomain: current psychopathology
MeasureReference: American Psychiatric Association 1994)

McLean Hospital Brain Imaging Center on a 1.5 Tesla General Electric Signa Scanner

AcquisitionType: MRI
Location: McLean Hospital Brain Imaging Center
MRField: 1.5 Tesla
Manufacturer: General Electric 
Model: Signa

structural acquisitions included a conventional T1-weighted sagittal scout series, a proton density/T2-weighted interleaved double-echo axial series, and a three-dimensional inversion recovery-prepped spoiled grass coronal series.

Socioeconomic status was assessed using the Hollingshead Scale. Onset of the disorder, number of episodes, and duration of illness were also obtained. Measures of psychopathology were obtained using the Mania Rating Scale (MRS),37,38 including the psychosis items, and the Global Assessment of Functioning (GAF).

All children, including the HCs, underwent diagnostic semistructured (Kiddie Schedule for Affective Disorders and Schizophrenia: Epidemiologic Version—KSADS-E)34 and clinical interviews by board-certified child psychiatrists. Each child received a physical and neurological examination (including Tanner Staging: a I–V scale of pubertal development).35,36 Additionally, parents were administered an indirect KSADS-E regarding their children (see Frazier et al12 for more detail).