Factor and latent class analysis of DSM-IV ADHD symptoms in a school sample of Brazilian adolescents

Objective: To evaluate the validity of the multidimensional construct propo sed by DSM-IV for the diagnosis of attention-deficit/hyperactivity disorder (ADHD) in a school sample of young Brazilian adolescents. Method: An instr ument including all 18 DSM-IVADHD symptoms was administered to 1,013 studen ts aged 12 to 14 years at 64 state schools by trained research assistants. Each symptom was rated on a Likert scale with five levels of severity (neve r, almost never, sometimes, frequently, and always). Results: Using an expl oratory factor analytic approach (principal components analysis), two facto rs were extracted. Factor I (hyperactivity-impulsivity) comprised eight DSM -IV hyperactive-impulsive symptoms with loadings greater than or equal to0. 40. Factor ii (inattention) included also eight DSM-IV symptoms of inattent ion. The two factors explained 34% of the total variance and had an interfa ctor correlation of 0.45. Latent class analysis demonstrated similar classe s in males and females, but class structures were markedly different from p revious analyses of parent report data. Conclusion: The findings support th e appropriateness of the multidimensional construct introduced by DSM-IV in the diagnosis of ADHD in a different culture but emphasize the possible im pact of different reporters on the results of structural model-testing.