Objective: To study the clinical characteristics of children who were diagnosed as ADHD.
Material and Method: A retrospective chart review was conducted on 202 children who came to a child mental health clinic and were diagnosed as ADHD.
Results: Most cases were in the 6-12 years age group and came from small families with 1-2 children. Males outnumbered females (M:F = 3.4:1). One-fifth of the sample received previous psychiatric evaluation from other health professionals but parents needed ?second opinion?. The most frequent chief complaints were academic/learning problems. Almost one-fourth of the samples came for problems not directly related to ADHD. In this group the most frequent complaints were aggressive and oppositional behavior. Comorbidity was found in 53.5%. More than half of the cases who took intelligence tests had an IQ below 90. Behavioral management was the only treatment modality in 38% of the sample. In 62% stimulants were instituted either at the beginning of treatment or as an ?add-on? after behavioral management proved to be insufficient. Among cases that received stimulants, 28% needed the combination of other psychotropic medications, mostly antidepressant and anxiolytic drugs.
Conclusion: A study of the clinical characteristics of ADHD in Thai children revealed male preponderance and high rates of non-ADHD presentations and comorbid conditions. Awareness of varied presentations of ADHD and proper treatment of comorbid conditions is imperative in the comprehensive care of ADHD children.

Keyword : ADHD, Hyperactive children, Inattention, Learning problems, Mental health problems