The Diagnostic and Statistical Manual of Mental Disorders – 4th edition (DSM-IV)1 was developed by the American Psychiatric Association and was used in the USA and the rest of the world for the formal diagnosis of attention-deficit hyperactivity disorder (ADHD) before it was replaced by the 5th edition (DSM-5TM).2 DSM-IV defined ADHD as "a persistent pattern of inattention and/or hyperactivity-impulsivity that is more frequently displayed and more severe than is typically observed in individuals at a comparable level of development". Symptoms must have been present from before age 7, although many patients are diagnosed years later.1

Overview of the DSM-IV medical classification system for ADHD1

  • Six or more symptoms of inattention and/or six or more symptoms of hyperactivity-impulsivity, present for at least six months prior to assessment
  • Hyperactive-impulsive or inattentive symptoms prior to 7 years of age
  • Impairment present in two or more settings (e.g. at home, and at school or at work)
  • Clinically significant impairment in social, academic or occupational environments
  • Symptoms do not occur exclusively in pervasive developmental disorder, schizophrenia, or other psychotic disorder, or are not better accounted for by another mental disorder

Individuals with ADHD may present with both inattention and hyperactivity/impulsivity, or one symptom pattern may predominate.1 In adults and adolescents, hyperactivity may present as feelings of restlessness and difficulty engaging in quiet, sedentary activities.1 Three subtypes of ADHD are commonly referred to: combined-type, inattentive-type and hyperactive/impulsive-type. According to the DSM-IV classification system, the appropriate subtype of ADHD should be indicated based on the predominant symptom pattern for the last six months.1

Subtypes of ADHD1

Subtype          Defining features    
Combined All three core features are present and ADHD is diagnosed when ≥6 symptoms of hyperactivity/impulsivity and inattention have been observed for ≥6 months
Inattentive Diagnosed if ≥6 symptoms of inattention (but <6 symptoms of hyperactivity/impulsivity) have persisted for ≥6 months
Hyperactive/impulsive Observed mostly in younger children and is diagnosed when ≥6 symptoms of hyperactivity/impulsivity (but <6 symptoms of inattention) have been present for ≥6 months


View references

  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC: American Psychiatric Association, 2004.
  2. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. Fifth edition. Washington, DC: American Psychiatric Association, 2013.

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