There are a number of assessment scales used to diagnose ADHD and measure the effectiveness of ADHD therapies. Some of the more popular assessment tools include the Diagnostic and Statistical Manual of Mental Disorders, 4^th Edition (DSM-IV) ADHD criteria, the Conner's/CADS Scale, the SKAMP, and CGI-I scales.

The American Academy of Pediatrics guidelines for diagnosing ADHD include:¹

	Evaluate any child 6 to 12 years of age who shows signs of school difficulties, academic underachievement, troublesome relationships with teachers, family members, peers, and other behavioral problems.
	Use DSM-IV criteria; these require that ADHD symptoms be present in 2 or more of a child's settings, and that the symptoms adversely affect the child's academic or social functioning for at least 6 months.
	Requires information from parents or caregivers and a teacher or other school professional regarding core symptoms of ADHD in various settings, age of onset, duration of symptoms, and degree of impairment.
	Assessment for co-existing conditions: learning and language problems, aggression, disruptive behavior, depression or anxiety.

Primary symptoms of ADHD include hyperactivity, inattention, and impulsivity. Children with ADHD may demonstrate 1, 2, or all 3 of these core symptoms, as outlined in the DSM-IV. Behavioral examples of these core symptoms include²:

1.	Hyperactivity
	Roaming around a room Talking incessantly Inability to sit through a lesson
2.	Inattention
	Difficulty in filtering out unnecessary distractions Being distracted or sidetracked by the movement of people or of objects
3.	Impulsivity
	Acting before thinking Demonstrating a very short temper Behavior that includes yelling or hitting

While children without ADHD may also occasionally demonstrate some of these symptoms, those with ADHD exhibit them across multiple settings, thus impairing the child's ability to function academically or socially on a daily basis.

ADHD contains subtypes with predominant traits. Therefore, a child without hyperactivity can still be affected by the disorder. The subtypes include:

	An inattentive subtype
	A hyperactive-impulsive subtype
	A combined subtype

Although boys are about 2 to 4 times as likely as girls to have ADHD,^3,4 girls are frequently diagnosed with the predominantly inattentive subtype⁵.

Children with ADHD often suffer from co-existing conditions, such as:

	Conduct disorders, described by the DSM-IV as "repetitive and persistent pattern(s) of behavior in which the basic rights of others or major age-appropriate societal norms or rules are violated (30%-50%)6
	Oppositional defiant disorder, defined by the DSM-IV as "a recurrent of negativistic, defiant, disobedient, and hostile behavior toward authority figures that persists for at least 6 months" (up to 40%)7
	Mood disorders (15%-20%)8
	Anxiety disorders (20%-25%)9

References

1. American Academy of Pediatrics. Diagnosis and evaluation of the child with attention-deficit/hyperactivity disorder. Pediatrics. 2000;105:1158-1170.
2. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. DSM-IV-TR. In: Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence: Diagnostic Criteria for Attention-Deficit/Hyperactivity Disorder. Washington, DC: American Psychiatric Association; 1994:92-93.
3. National Institute of Mental Health. National Institutes of Health. Attention deficit hyperactivity disorder. Available at: http://www.nimh.nih.gov/publicat/helpchild.cfm. Accessed April 19, 2002.
4. U.S. Department of Health and Human Services. Mental Health: A Report of the Surgeon General. Available at: http://www.surgeongeneral.gov/library/mentalhealth/chapter3/sec4.html. Accessed April 19, 2002.
5. Dulcan M. Practice parameters for the assessment and treatment of children, adolescents, and adults with attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry. 1997;369(suppl):855-1215.
6. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. DSM-IV-TR. In: Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence: Diagnostic Criteria for Attention-Deficit/Hyperactivity Disorder. Washington, DC: American Psychiatric Association; 1994:92-93.
7. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. DSM-IV-TR. In: Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence: Diagnostic Criteria for Attention-Deficit/Hyperactivity Disorder. Washington, DC: American Psychiatric Association; 1994:92-93.
8. National Institute of Mental Health. National Institutes of Health. Attention deficit hyperactivity disorder—questions and answers. Available at: http://www.nimh.nih.gov/publicat/adhdqa.cfm. Accessed April 19, 2002.
9. National Institute of Mental Health. National Institutes of Health. Attention deficit hyperactivity disorder—questions and answers. Available at: http://www.nimh.nih.gov/publicat/adhdqa.cfm. Accessed April 19, 2002.