American Psychiatric Association's Diagnostic and Statistics Manual (DSM-IV) criteria for Attention Deficit (ADHD)

A.  Either (1) or (2):
    (1) Inattention: at least *6* of the following symptoms of
        inattention have persisted for at least 6 months to a
        degree that is maladaptive and inconsistent with
        developmental level:
        (a) often fails to give close attention to details or
            makes careless mistakes in schoolwork, work, or other
            activities;
        (b) often has difficulty sustaining attention in tasks or
            play activities;
        (c) often does not seem to listen to what is being said to
            him/her;
        (d) often does not follow thru on instructions and fails
            to finish schoolwork, chores, or duties in the
            workplace (not due to oppositional behavior or failure
            to understand instructions);
        (e) often has difficulties organizing tasks and activities;
        (f) often avoids or strongly dislikes tasks (such as
            schoolwork or homework) that require sustained mental
            effort;
        (g) often loses things necessary for tasks or activities
            (e.g., school assignments, pencils, books, tools, or
            toys);
        (h) is often easily distracted by extraneous stimuli;
        (i) often forgetful in daily activities.
    (2) Hyperactivity-Impulsivity: at least *4* of the following
        symptoms of hyperactivity-impulsivity have  persisted for
        at least 6 months to a degree that is maladaptive and
        inconsistent with developmental level:
        Hyperactivity:
        (a) often fidgets with hands or feet or squirms in seat;
        (b) leaves seat in classroom or in other situations in
            which remaining seated is expected;
        (c) often runs about or climbs excessively in situations
            where it is inappropriate (in adolescents or adults,
            may be limited to subjective feelings of
            restlessness);
        (d) often has difficulty playing or engaging in leisure
            activities quietly.
       Impulsivity:
       (e) often blurts out answers to questions before the
           questions have been completed;
       (f) often has difficulty waiting in lines or awaiting turn
           in games or group situations.
B. Onset no later than age 7.
C. Symptoms must be present in 2 or more situations (e.g., at
   school, work, and at home).
D. The disturbance causes clinicaly significant distress or
   impairment in social, academic, or occupational functioning.
E. Does not occur exclusively during the course of PDD,
   Schizophrenia or other Psychotic Disorder, and is not better
   accounted for by Mood, Anxiety, Dissociative, or Personality
   Disorder.
Code based on type:
314.00 ADHD, Predominantly Inattentive Type if criterion A(1) is
met but not criterion A(2) for the past 6 months.
314.01 ADHD, Predominantly Hyperactive-Impulsive Type: if
criterion A(2) is met but not criterion A(1) for the past 6
months.
314.01 ADHD, Combined Type: if both criteria A(1) and (2) are met
for past 6 months [note: should this be 314.02?  It's not clear -
RDF]
314.9 is ADHD NOS, for other disorders with prominent symptoms of
attention-deficit or hyperactivity-impulsivity that do not meet
criteria above.