The most recent Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) describes ADHD as a childhood disorder causing developmentally inappropriate levels of inattention and/or hyperactive-impulsive behavior that appear before the age of seven and continue for more than six months. According to the DSM-IV-TR, to meet the criteria for diagnosis, there must be clear evidence of clinically significant impairment in social, academic, or occupational functioning in more than two distinct settings (e.g, at school, at work, or in social settings).
Generally, the symptoms of ADHD affect people most strongly in school where the environments are restrictive and children are asked to sit still and maintain focus for long periods of time. Because teachers observe children on a daily basis in relation to their peers, teachers are often the first people to recognize symptoms of ADHD, such as hyperactivity or inattentiveness.
As mentioned above, the DSM-IV-TR classifies ADHD into three types: 1. Predominantly Inattentive; (sometimes referred to as ADD) 2. Predominantly Hyperactive-Impulsive; and, 3. Combined
Each type of Attention-Deficit/Hyperactivity Disorder has a distinct set of behavioral symptoms. However, these symptoms are expressed differently in various developmental stages, so we will describe a list of associated behaviors for each age range.
Symptoms of Inattention during infancy can include:
- Difficult to soothe
- Less babbling speech the first year
- Poor sucking or crying during feeding
- Smiles less often. May not enjoy soft touch
Symptoms of Inattention during the preschool years can include:
- Strong will; unresponsive to discipline
- Some language difficulties
- Difficulties with structured play
- Toilet training problems
Symptoms of Inattention during the elementary school years can include:
- Failing to pay close attention to details or making careless mistakes when doing schoolwork or other activities
- Trouble keeping attention focused during play or tasks
- Appearing not to listen when spoken to
- Failing to follow instructions or finish tasks
- Avoiding tasks that require a high amount of mental effort and organization, such as school projects
- Frequently losing items required to facilitate tasks or activities, such as school supplies
- Excessive distractibility
- Procrastination, inability to begin an activity
- Associated problems such as low self-esteem, depression, or anxiety
Symptoms of Inattention during adolescence can include:
- Frequently shifting from one uncompleted task to another
- Difficulty organizing activities
- Serious academic inconsistencies
- Ongoing underachievement
- Difficulties with household activities (cleaning, paying bills, etc.)
- Often viewed as lazy or disinterested
- Associated mood or behavior problems become more pronounced
Inattention is often associated with poor school and work performance, because the individual has a hard time concentrating and absorbing the information as well as paying attention long enough to complete a task without being distracted. Those with the Inattentive, or Combined, type have a hard time focusing on any one task, or remembering things, and may avoid projects that require a lot of mental effort. They are easily bored, but can engage in intense concentration, or hyperfocus, on activities that interest them. Completing homework is quite difficult for inattentive children and may well lead to frustration for students as well as their parents. A lack of organizational skills and the ability to consciously develop them often creates additional problems for individuals with ADHD.
Symptoms of Hyperactivity during infancy can include:
- An aversion to being cuddled or held
- Strained/negative mother/child relationship
- More frequent crying
Symptoms of Hyperactivity during the preschool years can include:
- Higher activity levels than peers
- Problems noticeable in structured play
- Aggressive behavior
- Difficulty going to sleep
- Motor restlessness during sleep
- Strong will, "difficult to manage"
- Family disorganization and parents feeling overwhelmed
Symptoms of Hyperactivity during the elementary school years can include:
- Diminished need for sleep
- Fidgeting with hands or feet, or squirming in seat
- Leaving seat often, even when inappropriate
- Running or climbing at inappropriate times
- Difficulty with quiet play
- Frequent feelings of restlessness
- Excessive speech
Symptoms of Hyperactivity during adolescence can include:
- Decreased hyperactivity
- Pronounced feelings of restlessness
- Low self-esteem
- Intense need to stay busy and/or to do several things at once.
- Discipline problems
- High-risk behavior
Hyperactivity and impulsivity are generally associated with higher accident rates, greater problems with social interaction, and regular displays of angry outbursts. People with the Hyperactive or Combined types of ADHD always seem to be going somewhere or doing something. Children with hyperactivity appear to be constantly in motion and may often appear fidgety. They are noticeably more active than their peers, particularly during unstructured physical activities. They frequently become so engaged in unstructured activities that they do not recognize their own bodily signals regarding thirst, hunger or fatigue. Hyperactive children tend to dash around, touch whatever they come across, interrupt others, and talk constantly. They are often humming, singing, talking, or making other types of noises, and they are often quite loud. They tend to feel restless if they sit too long and have great difficulty slowing down enough to fall asleep. Once they fall asleep, they may sleep quite heavily, but also move actively throughout the night.
Symptoms of Impulsivity during infancy can include:
- Frequent crying and colic (painful bowel problems)
- Frequent infections, more allergies, etc
Symptoms of Impulsivity during the preschool years can include:
- Extreme excitability
- Gross/fine motor difficulties (awkward, clumsy)
- Fearlessness, may endanger self or others
- Low frustration tolerance
- Peer problems begin
Symptoms of Impulsivity during the elementary school years can include:
- Social immaturity
- Frequent arguments with parents and peers
- Disregards socially-accepted behavioral expectations
- Requires more supervision than average
- Inconsistent with responsibilities and chores
- Continually striving to be the center of attention
- Answering a question before the speaker has finished
- Failing to await one's turn
- Interrupting the activities of others at inappropriate times
- Poor peer relationships
Symptoms of Impulsivity during adolescence can include:
- Continued poor peer relationships
- Low self-esteem
- Discipline problems
- Continued frequent arguments
- Drug and alcohol abuse
- Risk-taking behavior
- Impulsive spending, leading to financial difficulties
Many experts consider the inability to think before acting and to tolerate delay to be the most significant problems for adolescents and adults with ADHD. Impulsivity can interfere greatly with social relationships, because individuals tend to display their emotions without thinking, blurt out inappropriate comments, and engage in behaviors that can be dangerous or hurtful without considering the consequences beforehand. Children who are very impulsive may take away another child's toy or hit when they get upset. Their impulsivity may make it hard for them to wait for things they want or to take their turn in games. Individuals with ADHD may choose to do things that are immediately rewarding in a small way, rather than waiting for a much larger long-term benefit in the future. For instance, an adolescent may engage in risk-taking or immediately self-gratifying behaviors without thinking of the consequences.
If present, the symptoms of hyperactivity and impulsivity generally appear before the symptoms of inattention. This is partly due to the fact that it is difficult to gauge attention levels in very young children. In addition, not being able to pay attention for long periods of time is developmentally appropriate for this age group. Therefore, minute differences in attentiveness cannot be observed as readily in the very young as can hyperactive and impulsive behavior, which are often hard to miss.
Symptoms are present by age 2 in 60% to 70% of children later diagnosed with ADHD, even if parents or caretakers do not clearly label the symptoms as such initially. Very young children are expected to be active and impulsive, so parents may not view such behaviors as excessive. As the child continues to age, the more readily visible hyperactive and impulsive behaviors may overshadow the symptoms of inattention. Hyperactivity and impulsivity may be more prominent at home, because paying attention is predominately an internal process rather than an external behavior. Thus, inattention symptoms are harder to identify and are often first noticed in the classroom where they can have a strong impact on school performance.
There is also an Attention-Deficit/Hyperactivity Disorder Not Otherwise Specified (NOS) diagnosis that is used when someone has symptoms that don't fit the exact diagnostic criteria for the other DSM types. For example, a person might be inattentive and impulsive, but not hyperactive; and therefore would not fit into any of the main 3 categories. This individual would best be diagnosed with ADHD Not Otherwise Specified.
Adults with ADHD are diagnosed using the same criteria, but with the stipulation that their symptoms must have been present prior to the age of seven. Evidence of this is often based on school records and historical information provided by the individual. Adult ADHD will be discussed in more detail later in this article.
Diagnostic Criteria Outside of the U.S.
The international community has reached an official agreement about the nature of ADHD. In 2001, over eighty experts specializing in this disorder signed and published the International Consensus Statement on ADHD. The purpose of this document was to challenge widely-held public skepticism that ADHD was not a true mental disorder requiring medication. Later, in 2005, an additional 100 experts from around Europe signed their names to the document, further strengthening and validating the statement that ADHD is indeed a valid mental disorder.
Internationally, the name and description of the disorder varies from the DSM terminology adopted within the United States. The 10th Edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) describes ADHD as a Hyperkinetic (i.e., excessive movement or dynamic energy) Disorder. More specifically, ADHD symptoms are classified as a Disturbance of Activity and Attention or a Hyperkinetic Disorder Unspecified (like the ADHD NOS category described above). In other words, problems maintaining attention are considered a separate disorder from the hyperactive component of a Hyperkinetic Disorder. In addition, if Conduct Disorder (blatant disregard for rules or the rights of others and an angry, defiant approach to authority) occurs alongside ADHD, the diagnosis becomes Hyperkinetic Conduct Disorder. ADHD has also been referred to in some references outside of the U.S. as Minimal Cerebral Dysfunction (MCD).