ADHD: History, Characteristics, and Diagnosis

1. 8 Attention-Deficit/HyperactivityDisorder (ADHD)

2. Description • Attention-deficit/hyperactivity disorder (ADHD) is exhibited as persistent age-inappropriate symptoms of inattention, hyperactivity, and impulsivity that are sufficient to cause impairment in major life activities • Characteristic behaviors vary considerably from child to child • Different behavior patterns may have different causes

3. History • Early 1900s • Children who lacked self-control and showed symptoms of overactivity/inattention in school were said to have poor “inhibitory volition” and “defective moral control” • Following the worldwide influenza epidemic from 1917-1926 • “Brain-injured child syndrome” • 1940s-1950s: “minimal brain damage” and “minimal brain dysfunction”

4. Historical Example

5. History (cont’d.) • Late 1950s • ADHD was called hyperkinesis • Led to definition of hyperactive child syndrome, in • By the 1970s • Deficits in attention and impulse control, in addition to hyperactivity, were seen as the primary symptoms • 1980s saw increased interest in ADHD • Rise in stimulant use generated controversy

6. Core Characteristics • Key symptoms fall under two well-documented categories • Inattention • Hyperactivity-impulsivity • Using these dimensions to define ADHD oversimplifies the disorder • Attention and impulse control are closely connected developmentally

7. DSM-V Diagnostic Criteria for ADHD

8. DSM-V Diagnostic Criteria for ADHD (cont’d.)

9. DSM-V Diagnostic Criteria for ADHD (cont’d.)

10. Inattention • Inability to sustain attention, particularly for repetitive, structured, and less enjoyable tasks • Deficits may be seen in one or more types of attention • Attentional capacity • Selective attention • Distractibility • Sustained attention/vigilance (a core feature)

11. Hyperactivity-Impulsivity • Inability to voluntarily inhibit dominant or ongoing behavior • Hyperactive behaviors include • Fidgeting and difficulty staying seated • Moving, running, touching everything in sight, excessive talking, and pencil tapping • Excessively energetic, intense, inappropriate, and not goal-directed

12. Hyperactivity-Impulsivity (cont’d.) • Impulsivity • Inability to control immediate reactions or to think before acting • Cognitive impulsivity includes disorganization, hurried thinking, and need for supervision • Behavioral impulsivity includes difficulty inhibiting responses when situations require it • Emotional impulsivity includes impatience, low frustration tolerance, hot temper, quickness to anger, and irritability

13. ADHD Presentation Types • Predominantly inattentive presentation (ADHD-PI) • Predominantly hyperactive–impulsive presentation (ADHD-HI) • Combined presentation (ADHD-C)

14. Predominantly Inattentive Type (ADHD-PI) • Inattentive, drowsy, daydreamy, spacey, in a fog, and easily confused • May have learning disability, process information slowly, have trouble remembering things, and display low academic achievement • Often anxious, apprehensive, socially withdrawn, and may display mood disorders

15. Predominantly Hyperactive-Impulsive Type (ADHD-HI) • Primarily symptoms of hyperactivity-impulsivity (rarest group) • Primarily includes preschoolers and may have limited validity for older children • May be a distinct subtype of ADHD-C

16. Combined Type (ADHD-C) • Children who have symptoms of both inattention and hyperactivity-impulsivity • Most often referred for treatment

17. Additional DSM Criteria • Appears prior to age 12 • Persists more than 6 months • Occurs more often and with greater severity than in: • Other children of the same age and sex • Occur across two or more settings • Interferes with social or academic performance • Not explained by another disorder

18. What DSM Criteria Don’t Tell Us • Limitations of DSM criteria for ADHD • Developmentally insensitive • Categorical view of ADHD • DSM criteria shape our understanding of ADHD • DSM criteria are also shaped by, and in some instances lag behind, new research findings

19. Associated Characteristics • Children with ADHD often display other problems in addition to their primary difficulties • Cognitive deficits • Speech and language impairments • Developmental coordination and tic disorders • Medical and physical concerns • Social problems

20. Cognitive Deficits: Executive Functions • Cognitive processes • Language processes • Motor processes • Emotional processes

21. Examples of Impaired Executive Functions

22. Cognitive Deficits: Intellectual and Academic • Intellectual deficits • Most children with ADHD have at least normal intelligence - the difficulty lies in applying intelligence to everyday life situations • Impaired academic functioning • Children with ADHD frequently have lower productivity, grades, and scores on achievement tests

23. Cognitive Deficits: Learning Disorders and Self-Perceptions • Learning disorders are common for children with ADHD • Problem areas: reading, spelling, and math • Distorted self-perceptions • Positive bias: exaggeration of one’s competence • Self-esteem in children with ADHD may vary with the subtype of ADHD • Distortions in perceptions of quality of life

24. Speech and Language Impairments • Formal speech and language disorders • Difficulty understanding others’ speech • Excessive and loud talking • Frequent shifts and interruptions in conversation • Inability to listen • Inappropriate conversations • Speech production errors

25. Developmental Coordination and Tic Disorders • As many as 30-50% of children with ADHD display motor coordination difficulties • Clumsiness, poor performance in sports, or poor handwriting • Overlap exists between ADHD and developmental coordination disorder (DCD) • Marked motor incoordination and delays in achieving motor milestones

26. Developmental Coordination and Tic Disorders (cont’d.) • Tic disorders occur in 20% of children with ADHD • Sudden, repetitive, nonrhythmic motor movements or sounds such as eye blinking, facial grimacing, throat clearing, and grunting

27. Medical and Physical Concerns • Health-related problems • Higher rates of asthma and bedwetting • Studies’ findings are inconsistent • Sleep disturbances may be related to use of stimulant medications and/or co-occurring conduct or anxiety disorders

28. Medical and Physical Concerns (cont’d.) • Accident-proneness and risk taking • Over 50% are described as being accident-prone • At higher risk for traffic accidents • At risk for early initiation of cigarette smoking, substance use disorders, and risky sexual behaviors • Reduced life expectancy • Higher medical costs

29. Social Problems • Family problems include: • Negativity, child noncompliance, excessive parental control, sibling conflict, maternal depression, paternal antisocial behavior, and marital conflict • Family difficulties may be due to co-occurring conduct problems

30. Social Problems (cont’d.) • Peer problems • ADHD children can be bothersome, stubborn, socially awkward, and socially insensitive • They are often disliked and uniformly rejected by peers, have few friends • They are unable to apply their social understanding in social situations • Positive friendships may buffer negative outcomes

31. Accompanying Psychological Disorders and Symptoms • Up to 80% of children with ADHD have a co-occurring psychological disorder • Oppositional Defiant Disorder (ODD) and Conduct Disorder (CD) • Role of COMT gene • A common genetic contribution for ADHD, ODD, and CD • Family connections – there is evidence for a contribution from a shared environment

32. Accompanying Psychological Disorders and Symptoms Anxiety Disorders • Anxiety disorders • About 25% of children with ADHD experience excessive anxiety • Co-occurring anxiety worsens symptoms or severity of ADHD • Findings are inconsistent • Children with co-occurring ADHD and anxiety: • Display social and academic difficulties • Experience greater long-term impairment and mental health problems

33. Accompanying Psychological Disorders and Symptoms Mood Disorders • Mood disorders • ADHD at 4-6 years is a risk factor for future depression and suicidal behavior • 20-30% of children with ADHD experience depression • Family risk for one disorder may increase the risk for the other • Controversy regarding relationship between ADHD and pediatric bipolar disorder (BP)

34. Prevalence and Course • Prevalence rates vary widely with sampling methods • Estimates: 6-7% of school-age children and adolescents in North America and 5% worldwide have ADHD • ADHD is one of the most common referral problems seen at clinics

35. Gender • ADHD occurs more frequently in boys • Overall rates decrease in adolescence for both sexes - ratio remains the same • Ratio in clinical samples is 6:1 with boys being referred more often than girls • ADHD in girls may go unrecognized and unreported • DSM criteria (cutoffs and symptoms) may be more appropriate to boys than girls

36. Gender (cont’d.) • Girls with ADHD may be more likely to display inattentive/disorganized symptoms • Clinic-referred school-age children with ADHD display similar symptoms • Girls with ADHD who display impulsive-hyperactive behaviors • More likely to develop eating disorder symptoms

37. Socioeconomic Status and Culture • ADHD affects children from all social classes • Slightly more prevalent among lower SES groups • Findings are inconsistent regarding relationships among ADHD, race, and ethnicity • ADHS is found in all countries and cultures • Rates vary

38. Socioeconomic Status and Culture (cont’d.) • Cultural differences may reflect cultural norms and tolerance for ADHD symptoms • ADHD is a universal phenomenon that is diagnosed more often in boys than girls in all cultures • Expression, associated features, impairments, and outcomes are quite similar wherever it occurs

39. Course and Outcome • Infancy • Signs of ADHD may be present at birth - no reliable or valid methods exist to identify it • Preschool • Hyperactivity-impulsivity symptoms become more visible and significant at ages 3-4 • Children with symptoms for at least 1 year are likely to continue to have difficulties later in middle childhood and adolescence

40. Course and Outcome Elementary School • Symptoms are especially evident when the child starts school • Oppositional defiant behaviors may increase or develop • By age 8-12, defiance and hostility may take the form of serious problems • Increased problems may encompass self-care, personal responsibility, chores, trustworthiness, independence, social relationships, and academic performance

41. Course and Outcome Adolescence and Adulthood • Many children with ADHD do not outgrow problems and some can get much worse • At least 50% of clinic-referred elementary school children continue to suffer from ADHD into adolescence • Adult challenges • Some individuals either outgrow or learn to cope with their disorder by adulthood • ADHD is established as an adult disorder

42. Theories and Causes • Explanations for ADHD • Trait from evolutionary past as hunters • ADHD is a myth fabricated because society needs it • Some theories • Cognitive functioning deficits • Reward/motivation deficits • Arousal level deficits • Self-regulation deficits

43. A Possible Developmental Pathway for ADHD

44. Genetic Influences • ADHD runs in families • Adoption studies • Twin studies • 75% heritability estimates for hyperactive-impulsive and inattentive behaviors • Specific gene studies • Genes may contribute to the expression of ADHD – focus on dopamine regulation

45. Pregnancy, Birth, and Early Development • Factors that compromise development of the nervous system before and after birth may be related to ADHD • Mother’s use of cigarettes, alcohol, or other drugs during pregnancy are associated with ADHD • Contributing factors, rather than a causal association • It is difficult to disentangle substance abuse influence and other environmental factors

46. Neurobiological Factors • Research shows differences on: • Psychophysiological measures • Diminished arousal or arousability • Measures of brain activity during vigilance tests • Under-responsiveness to stimuli/deficits in response inhibition • Blood flow to prefrontal regions and pathways connecting them to limbic system • Decreased blood flow to these regions

47. Brain Abnormalities • Abnormalities primarily in the frontostriatal circuitry are implicated • This region includes the prefrontal cortex and the basal ganglia • ADHD children have smaller total and right cerebral volumes (by 3-4%), smaller cerebellum, and delayed brain maturation • Specific regions of the thalamus may also be involved

48. Neurophysiological and Neurochemical Associations • No consistent differences have been found between children with and without ADHD • Some neurotransmitters may be involved • Dopamine, norepinephrine, epinephrine, and serotonin may be involved • Most evidence suggests a selective deficiency in availability of dopamine and norepinephrine • Using medication for effective treatment of ADHD symptoms does not prove that deficits are the cause of symptoms

49. Diet, Allergy, and Lead • Sugar is not the cause of hyperactivity • Allergic reactions and diet • Possible moderating role of genetic factors may explain why food additives affect the behavior of some children • Low levels of lead may be associated with ADHD symptoms • The role of diet, allergy, and lead as primary causes of ADHD is minimal to nonexistent

50. Family Influences • Importance of family influences • Family influences may lead to ADHD symptoms or to a greater severity of symptoms • Family problems may result from interacting with a child who is difficult to manage • Family conflict is likely related to the presence, persistence, or later emergence of associated oppositional and conduct disorder