Longitudinal Assessment of Manic Symptoms (LAMS) Study: Background, Design, and Initial Screening Results

Objective: To describe the design of a longitudinal study of youth with elevated symptoms of mania (ESM), as well as the prevalence and correlates of manic symptoms. Bipolar disorder in youth is serious and is surrounded by controversy about its phenomenology, course, and treatment. Yet, there are no longitudinal studies of youth selected only for ESM, the phenomenological hallmark. The study’s objective is to document the rate and sociodemographic correlates of ESM in children attending outpatient psychiatric clinics.

Method: Parents of 3,329 children aged 6-12 years visiting 10 outpatient clinics were asked to complete the Parent General Behavior Inventory 10-Item Mania Scale (PGBI-10M). Children with PGBI-10M scores ≥ 12 (ESM positive-screen [ESM+]) and a matched sample of ESM screen-negative (ESM−) children were invited to enroll in the longitudinal study. The sample was accrued from November 14, 2005, to November 28, 2008.

Results: Most of the children whose parents filled out the PGBI-10M (N = 2,622, 78.8%) participated in the study. Nonparticipants were slightly younger (mean age = 9.1 years [SD = 2.0 years] versus 9.4 years [SD = 2.0 years] for participants; t3327 = 4.42, P < .001). Nearly half of the participants (43%) were ESM+; these were more likely to be Latino (4.2% versus 2.5% for ESM−; χ21 = 5.45, P = .02), younger (mean age = 9.3 years [SD = 2.0 years] versus 9.6 years [SD = 1.9 years] for ESM−; t2620 = 3.8, P < .001), and insured by Medicaid (48.4% versus 35.4% for ESM−; χ21 = 45.00, P < .001). There were no sociodemographic differences between those who did versus did not agree to enroll in the longitudinal portion (yes to enrollment: n = 621, 55.2%; no to enrollment: n = 503, 44.8%). Four items best discriminated ESM+ children from ESM− children. Three of the 4 items were not the most commonly endorsed items, but all were indicative of behavioral extremes.

Conclusions: Data suggest that ESM+ is not rare in 6- to 12-year-olds. Children who are ESM+ show behavioral extremes, including rapid mood shifts, compared to ESM− children.

J Clin Psychiatry

Submitted: November 16, 2009; accepted March 2, 2010.

Online ahead of print: October 5, 2010 (doi:10.4088/JCP.09m05835yel).

Corresponding author: Sarah McCue Horwitz, PhD, Department of Pediatrics and Stanford Health Policy, Stanford University School of Medicine, 117 Encina Commons, Stanford, CA 94305-6019 ([email protected]).