The Official DSM IV-TR Differential Diagnosis of ADHD:

<font color="green">Attention Deficit/Hyperactivity Disorder
Text taken directly from the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM IV-TR)

Differential Diagnosis

In early childhood, it may be difficult to distinguish symptoms of Attention-Deficit/ Hyperactivity Disorder from age-appropriate behaviors in active children (e.g., running around or being noisy).

Symptoms of inattention are common among children with low IQ who are placed in academic settings that are inappropriate to their intellectual ability. These behaviors must be distinguished from similar signs in children with Attention-Deficit/Hyperactivity Disorder.

In children with Mental Retardation, an additional diagnosis of Attention-Deficit/Hyperactivity Disorder should be made only if the symptoms of inattention or hyperactivity are excessive for the child's mental age. Inattention in the classroom may also occur when children with high intelligence are placed in academically understimulating environments. Attention-Deficit/Hyperactivity Disorder must also be distinguished from difficulty in goal-directed behavior in children from inadequate, disorganized, or chaotic environments. Thorough histories of symptom pattern obtained from multiple informants (e.g., baby-sitters, grandparents, or parents of playmates) are helpful in providing a confluence of observations concerning the child's inattention, hyperactivity, and capacity for developmentally appropriate self-regulation in various settings.

Individuals with oppositional behavior may resist work or school tasks that require self-application because of an unwillingness to conform to others' demands. These symptoms must be differentiated from the avoidance of school tasks seen in individuals with Attention-Deficit/Hyperactivity Disorder. Complicating the differential diagnosis is the fact that some individuals with Attention-Deficit/Hyperactivity Disorder develop secondary oppositional attitudes toward such tasks and devalue their importance, often as a rationalization for their failure.

The increased motor activity that may occur in Attention-Deficit/Hyperactivity Disorder must be distinguished from the repetitive motor behavior that characterizes Stereotypic Movement Disorder. In Stereotypic Movement Disorder, the motor behavior is generally focused and fixed (e.g., body rocking, self-biting), whereas the fidgetiness and restlessness in Attention-Deficit/Hyperactivity Disorder are more typically generalized. Furthermore, individuals with Stereotypic Movement Disorder are not generally overactive; aside from the stereotypy, they may be underactive.

Attention-Deficit/Hyperactivity Disorder is not diagnosed if the symptoms are better accounted for by another mental disorder (e.g., Mood Disorder [especially Bipolar Disorder], Anxiety Disorder, Dissociative Disorder, Personality Disorder, Personality Change Due to a General Medical Condition, or a Substance-Related Disorder). In all these disorders, the symptoms of inattention typically have an onset after age 7 years, and the childhood history of school adjustment generally is not characterized by disruptive behavior or teacher complaints concerning inattentive, hyperactive, or impulsive behavior.

When a Mood Disorder or Anxiety Disorder co-occurs with Attention-Deficit/Hyperactivity Disorder, each should be diagnosed. Attention-Deficit/Hyperactivity Disorder is not diagnosed if the symptoms of inattention and hyperactivity occur exclusively during the course of a Pervasive Developmental Disorder or a Psychotic Disorder. Symptoms of inattention, hyperactivity, or impulsivity related to the use of medication (e.g., bronchodilators, isoniazid, akathisia from neuroleptics) in children before age 7 years are not diagnosed as Attention-Deficit/Hyperactivity Disorder but instead are diagnosed as Other Substance-Related Disorder Not Otherwise Specified. </font>