Attention-based classification pattern, a research domain criteria framework, in youths with bipolar disorder and attention-deficit/hyperactivity disorder.
OBJECTIVE
The National Institute of Mental Health has initiated the Research Domain Criteria (RDoC) project. Instead of using disorder categories as the basis for grouping individuals, the RDoC suggests finding relevant dimensions that can cut across traditional disorders. Our aim was to use the RDoC's framework to study patterns of attention deficit based on results of Conners' Continuous Performance Test (CPT II) in youths diagnosed with bipolar disorder (BD), attention-deficit/hyperactivity disorder (ADHD), BD+ADHD and controls.


METHODS
Eighteen healthy controls, 23 patients with ADHD, 10 with BD and 33 BD+ADHD aged 12-17 years old were assessed. Pattern recognition was used to partition subjects into clusters based simultaneously on their performance in all CPT II variables. A Fisher's linear discriminant analysis was used to build a classiﬁer.


RESULTS
Using cluster analysis, the entire sample set was best clustered into two new groups, A and B, independently of the original diagnoses. ADHD and BD+ADHD were divided almost 50% in each subgroup, and there was an agglomeration of controls and BD in group B. Group A presented a greater impairment with higher means in all CPT II variables and lower Children's Global Assessment Scale. We found a high cross-validated classiﬁcation accuracy for groups A and B: 95.2%. Variability of response time was the strongest CPT II measure in the discriminative pattern between groups A and B.


CONCLUSIONS
Our classificatory exercise supports the concept behind new approaches, such as the RDoC framework, for child and adolescent psychiatry. Our approach was able to define clinical subgroups that could be used in future pathophysiological and treatment studies.
Institute of Psychiatry, São Paulo, Brazil anakleinman@terra.com.br.
Ana
A
Kleinman
Institute of Psychiatry, São Paulo, Brazil.
Sheila Cavalcante
SC
Caetano
Institute of Psychiatry, São Paulo, Brazil.
Helena
H
Brentani
Institute of Psychiatry, São Paulo, Brazil.
Cristiana Castanho de Almeida
CC
Rocca
Institute of Mathematics and Statistics, São Paulo, Brazil.
Bernardo
B
dos Santos
Institute of Psychiatry, São Paulo, Brazil.
Enio Roberto
ER
Andrade
Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Cristian Patrick
CP
Zeni
Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Silzá
S
Tramontina
Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
Luis Augusto Paim
LA
Rohde
Institute of Psychiatry, São Paulo, Brazil University of São Paulo, São Paulo, Brazil.
Beny
B
Lafer
D000293:Adolescent; D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000175:diagnosis* / Q000523:psychology*; D001714:Bipolar Disorder / Q000150:complications / Q000175:diagnosis* / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales
Research Domain Criteria (RDoC); attention; attention-deficit/hyperactivity disorder; bipolar disorder; continuous performance test; youth