International Meeting for Autism Research: ADHD Subtypes In a Large ASD Mexican Clinical Sample

ADHD Subtypes In a Large ASD Mexican Clinical Sample

Thursday, May 12, 2011
Elizabeth Ballroom E-F and Lirenta Foyer Level 2 (Manchester Grand Hyatt)
11:00 AM
H. Padilla-Amezcua1, O. Roldan-Ceballos2, O. Nafate-Lopez3, W. O. Lopez Martinez3, P. Zavaleta-Ramírez4, D. C. Melchor Contreras3, G. Villarreal-Valdes5 and L. Albores-Gallo5, (1)Research Division, Hospital Psiquiatrico Infantil Dr. Juan N. Navarro, Tlalpan, Mexico, (2)Research Division, Asociacion Mexicana de Ninos con TDA y trastornos asociados A.C., Mexico D.F., Mexico, (3)Research Division, Hospital Psiquiatrico Infantil, Mexico D.F., Mexico, (4)Adolescent Clinic, Instituto Nacional de Psiquiatria Ramon de la Fuente, Mexico D.F., Mexico, (5)Research Division, Hospital Psiquiatrico Infantil , Mexico D.F., Mexico

In the last decade several authors have investigated the co- morbidity of ADHD in ASD population. Concurrent diagnosis of ADHD and PDD is not allowed in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).  Although differences in ADHD subtypes among PDD and non PDD samples have been investigated previously, fewer studies have done comparisons with ADHD population.

Objectives:  To investigate ADHD subtypes in a large ASD and ADHD clinical population.

Methods:  Children admitted to the outpatient developmental behavioral Clinic of Psychiatric Hospital Dr. Juan N. Navarro were recruited for this study. Measures: ADI-R routinely performed to this population was use as gold standard diagnosis. A semi structured interview was conducted to assign subtypes for ASD (Autism, Asperger and PDDNOS) and ADHD DSM-IV diagnosis (Inattentive, Combined and Hyperactive-Impulsive). These interviews were done by senior board certified child psychiatrist LAG.


The study sample consisted of 218 children aged 2-17 years old (M 7.68, SD 3.29), 82.6% were masculine. Within this sample 50.5% of the children (n=110) were diagnosed with Autism, (15.1%) were Asperger (n=33) and 6% had PDDNOS (n=13). The Non ASD sample 28.4% (n=62) was identified as ADHD. The ADHD prevalence in the ASD sample was 80.01% which was higher for Autism 81.8% and Asperger 78.8% compared to PDDNOS 69.2% but differences were non- significant (p=.54).  In the ADHD sample, 31children (50.0%) had the inattentive type, 27 (43.5%) had the combined type and 4 (6.5%) had the hyperactive-impulsive type of ADHD. Subtypes prevalence between ASD and ADHD sample was very similar. Through multinomial logistic regression the risk for ADHD was higher for autism OR 2.0 (CI 95% 0.56-7.00).14 and for Asperger OR 1.61 (CI 95% 0.39-6.99) although non-significant.


These results show that ADHD prevalence is higher in ASD samples. The subtype pattern of prevalence in ASD is similar to ADHD clinical samples.

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