ADHD Symptoms and Prevalence (DSM-5)

ADHD (DSM-5) Symptoms and Prevalence

• ADHD is a persistent pattern of inattention and/or hyperactivity-impulsivity, significantly higher than expected for a child's developmental stage.
• Behaviors can include lack of attention in various settings (academic, occupational, social), making careless mistakes, difficulty maintaining focus, not listening, disorganization, and difficulty completing tasks requiring sustained effort.
• Hyperactivity can manifest as excessive fidgeting, leaving seats inappropriately, excessive running/climbing, excessive talking, and always being "on the go".
• Impulsivity includes interrupting, impatience, and a desire for immediate gratification.
• Symptoms must be present before age 12, present in at least two settings, and impact educational, social, or occupational functioning.
• ADHD is diagnosed in approximately 5% of school-aged and preschool children and 2.5% of adults globally. Boys are more often diagnosed than girls, thought this may be due to greater referral rates and girls exhibiting less disruptive behaviors. However, sex differences in presentation may not be seen in adulthood.

ADHD Diagnosis

• Diagnosis requires an ongoing pattern of inattention and/or hyperactivity-impulsivity.
• Inattention criteria: at least six symptoms are required for at least 6 months. Includes difficulty paying attention to details, difficulty sustaining attention in activities, difficulty listening, following instructions, disorganization, avoiding tasks requiring sustained mental effort, losing things, distractibility, and forgetfulness.
• Hyperactivity/Impulsivity: 6 or more symptoms are required for at least 6 months. Includes excessive fidgeting, inability to sit still, excessive running/climbing, difficulty engaging in quiet activities, excessive talking, blurting out answers, interrupting, and difficulty waiting their turn.
• Symptoms must be present in at least two settings (e.g., home and school)
• Symptoms must interfere with normal functioning or development.

ADHD Subtypes

• Predominantly inattentive presentation: meeting only the inattention criteria in the past 6 months.
• Predominantly hyperactive/impulsive presentation: meeting only the hyperactivity/impulsivity criteria in the past 6 months.
• Combined presentation: meeting both inattention and hyperactivity/impulsivity criteria.

Comorbidities

• Oppositional defiant disorder (ODD) is found in 50% of individuals diagnosed with combined presentation.
• Conduct disorder (CD) may be a comorbidity, and occurs in 45-60% of ADHD children.
• Anxiety and depression are comorbid in a minority of children with ADHD.
• Adults with ADHD are at increased risk for antisocial personality disorder, substance abuse, mood disorders, anxiety disorders, marital problems, traffic accidents, and frequent job changes.

Causes of ADHD

• Strong genetic component, with a heritability of 76%. This affects dopamine, norepinephrine, and serotonin systems.
• Specific genes (dopamine transporter gene, dopamine D4 and D5 receptors, SNAP-25) are implicated and have small individual effects.
• Environmental interactions are significant. Prenatal exposure to nicotine, pre- or perinatal complications, maternal drinking during pregnancy, low birth weight, lead exposure, and exposure to chronic nicotine are examples of environmental factors influencing ADHD.

Treatments of ADHD

• Stimulant medications (methylphenidate, amphetamines) are highly effective, reducing demanding, disruptive, and non-compliant behaviors in over 70% of ADHD children.
• Non-stimulant medications (atomoxetine, clonidine, guanfacine) impact norepinephrine levels and are sometimes used as second-line treatments.
• Behavioral therapies are also effective in reducing symptoms, reinforcing positive behaviors and extinguishing negative ones. These interventions often involve parents and teachers.
• Combined medication and behavioral therapies typically yield the best outcomes.

Cognitive, Psychological and other Factors

• Children with ADHD show impaired executive function, particularly with planning and inhibition.
• Psychological factors include parenting styles, especially authoritarian methods.
• ADHD children may find it difficult to make friends or integrate into social groups.
• Symptoms often decrease during adolescence, but about half of adults will still show symptoms.
• Adults often face issues in maintaining steady employment, relationships, social life and safety.

Cognitive Tests of ADHD and Treatments

• Continuous Performance Test (CPT): measures sustained attention and response inhibition, common in ADHD.
• Stroop Task: measures the ability to inhibit responses and color naming, common in ADHD.
• Trail Making Test: measures cognitive flexibility and attention, common in ADHD
• Controlled Word Association Test (COWAT): measures verbal fluency and category fluency.
• Conners' Parent Rating Scale (CPRS): an 80-item scale completed by the child's parent used to assess ADHD symptoms.

Non-Pharmacological Treatments

• Behavioral therapies help change behaviors and thought patterns, which are vital components of treatment to be sustainable
• Cognitive training to improve attention, and executive functions.
• Neurofeedback, a form of biofeedback, may help improve self-control over brain activity patterns.
• Dietary modifications, like removing artificial food colors and other dietary interventions, have some impact at changing ADHD symptoms, though not huge.

Other important points

• Symptoms reduce over time in children with ADHD
• There is often overlap of ADHD symptoms and other conditions. ADHD is a major condition impacting overall well-being, so timely and appropriate interventions are recommended.
• Computerized training of working memory is a potentially effective intervention to treat ADHD symptoms.
• The relationship between ADHD and motivational factors and delay aversion has also been explored. There may be pathways for ADHD as a motivational style, differing from the pathway of regulation of thought and action.