Oppositional Defiant Disorder (ODD) is not a pervasive developmental disorder. The most common manual used as a “standard” for definitions of mental disorders (developmental or otherwise) is the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, American Psychiatric Association (1994) (often referred to as the “DSM – Four”). Under a section titled: Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence there is a subsection called Pervasive Developmental Disorders. The five pervasive developmental disorders are: Autistic Disorder, Rett’s Disorder, Childhood Disintegrative Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder Not Otherwise Specified (Including Atypical Autism). ODD is in the same major section, but in the subsection titled: Attention-Deficit and Disruptive Behavior Disorders.