CBCL pediatric bipolar disorder profile and ADHD: comorbidity and quantitative trait loci analysis.
OBJECTIVE
The pediatric bipolar disorder profile of the Child Behavior Checklist (CBCL-PBD), a parent-completed measure that avoids clinician ideological bias, has proven useful in differentiating patients with attention-deficit/hyperactivity disorder (ADHD). We used CBCL-PBD profiles to distinguish patterns of comorbidity and to search for quantitative trait loci in a genomewide scan in a sample of multiple affected ADHD sibling pairs.


METHODS
A total of 540 ADHD subjects ages 5 to 18 years were assessed with the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version and CBCL. Parents were assessed with the Schedule for Affective Disorders and Schizophrenia-Lifetime version supplemented by the Schedule for Affective Disorders and Schizophrenia for School-Age Children for disruptive behavioral disorders. Patterns of psychiatric comorbidity were contrasted based on the CBCL-PBD profile. A quantitative trait loci variance component analysis was used to identify potential genomic regions that may harbor susceptibility genes for the CBCL-PBD quantitative phenotype.


RESULTS
Bipolar spectrum disorders represented less than 2% of the overall sample. The CBCL-PBD classification was associated with increased generalized anxiety disorder (p =.001), oppositional defiant disorder (p =.008), conduct disorder (p =.003), and parental substance abuse (p =.005). A moderately significant linkage signal (multipoint maximum lod score = 2.5) was found on chromosome 2q.


CONCLUSIONS
The CBCL-PBD profile distinguishes a subset of ADHD patients with significant comorbidity. Linkage analysis of the CBCL-PBD phenotype suggests certain genomic regions that merit further investigation for genes predisposing to severe psychopathology.
McGough
James J
JJ
Division of Child and Adolescent Psychiatry, UCLA Semel Institute for Neuroscience and Human Behavior and David Geffen School of Medicine, USA.jmcgough@mednet.ucla.edu
Loo
Sandra K
SK
McCracken
James T
JT
Dang
Jeffrey
J
Clark
Shaunna
S
Nelson
Stanley F
SF
Smalley
Susan L
SL
D000293:Adolescent; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D057189:Checklist; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D015897:Comorbidity; D019955:Conduct Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D010552:Personality Assessment / Q000706:statistics & numerical data*; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics*