Causes of ADHD
ADHD is a neurodevelopmental disorder with multiple contributing factors. It is highly heritable and involves brain differences.
Biological Causes
Genetics (Primary Factor):
- Highly heritable: 70-80% heritability
- Runs strongly in families
- If one parent has ADHD: 40-57% chance for child
- Twin studies show high concordance
- Multiple genes involved (polygenic)
- Genes affect:
- Dopamine regulation (DRD4, DRD5, DAT1 genes)
- Norepinephrine systems
- Brain development
Brain Differences:
Structural:
- Smaller overall brain volume (3-5% smaller)
- Reduced size in specific regions:
- Prefrontal cortex (executive functions)
- Basal ganglia (movement, attention)
- Cerebellum (coordination, cognitive control)
- Corpus callosum (connecting hemispheres)
- Differences often decrease with age (brain development delayed)
Functional:
- Underactivity in prefrontal cortex
- Different activation patterns during attention tasks
- Less efficient neural networks
- Default mode network doesn’t deactivate properly
Neurotransmitter Differences:
- Dopamine dysregulation: Primary neurotransmitter involved
- Reduced dopamine activity in reward and attention circuits
- Affects motivation and attention
- Norepinephrine: Also involved in attention and alertness
- Medications target these systems
Prenatal/Perinatal Risk Factors
Maternal Factors During Pregnancy:
- Smoking
- Alcohol use
- Drug use (especially cocaine)
- Severe stress
- Nutritional deficiencies
Birth Complications:
- Prematurity (especially very premature)
- Very low birth weight
- Birth complications/trauma
- Oxygen deprivation
Environmental Toxins:
- Lead exposure (even low levels)
- Pesticides
- PCBs (polychlorinated biphenyls)
Note: These are risk factors, not direct causes; interact with genetic vulnerability
Psychosocial Factors
Not Causes But May Worsen:
- Family stress and dysfunction
- Chaotic home environment
- Inconsistent parenting
- Early institutional care/neglect
- Low socioeconomic status
Important: Poor parenting does NOT cause ADHD, but environment affects symptom expression and outcomes
Debunked Myths (NOT Causes)
- Sugar: No evidence sugar causes ADHD
- Food additives: Minimal effect in small subset
- Too much TV/video games: May worsen attention but don’t cause ADHD
- Poor parenting: Not a cause (though affects outcomes)
- Vaccines: No link whatsoever
Treatment of ADHD
Multimodal Treatment Approach
Most Effective: Combination of medication + behavioral interventions + school supports
Pharmacological Treatment
Medications Are First-Line Treatment (especially for moderate-severe ADHD)
Stimulant Medications (Most Effective):
Methylphenidate-Based:
- Ritalin (immediate release, 3-4 hours)
- Concerta (extended release, 12 hours)
- Focalin
- Daytrana (patch)
Amphetamine-Based:
- Adderall (mixed amphetamine salts)
- Vyvanse (lisdexamfetamine, longest acting)
- Dexedrine
How They Work:
- Increase dopamine and norepinephrine in brain
- Improve attention, reduce impulsivity and hyperactivity
- Effects within 30-60 minutes
- Effective in 70-80% of individuals
Benefits:
- Improved attention and focus
- Reduced impulsivity
- Decreased hyperactivity
- Better academic/work performance
- Improved social interactions
- Enhanced executive functioning
Side Effects (Usually Mild):
- Decreased appetite
- Sleep problems (insomnia)
- Headaches
- Stomachaches
- Irritability (“rebound” when wears off)
- Temporary growth slowdown (minimal, catches up)
- Increased heart rate/blood pressure (monitor)
Misconceptions:
- NOT addictive when used as prescribed
- Don’t lead to substance abuse (actually reduce risk)
- Don’t change personality
- Effects don’t diminish over time
Non-Stimulant Medications (Second-Line):
Atomoxetine (Strattera):
- Norepinephrine reuptake inhibitor
- Takes 4-6 weeks for full effect
- 24-hour coverage
- Good if stimulants not tolerated or substance abuse concern
- Less effective than stimulants but still helpful
Guanfacine (Intuniv) and Clonidine (Kapvay):
- Alpha-2 agonists
- Help with hyperactivity and impulsivity
- Also help with sleep
- Can be added to stimulants
Antidepressants (Rarely Used):
- Bupropion (Wellbutrin)
- Tricyclics (rarely, due to side effects)
- Only if other medications fail
Medication Management:
- Start low, increase gradually
- Monitor effectiveness and side effects
- Regular follow-ups
- May need adjustments
- “Drug holidays” (breaks) controversial; not usually recommended
Behavioral Interventions
Behavioral Parent Training (Evidence-Based):
Techniques:
- Positive reinforcement for desired behaviors
- Clear, consistent rules and consequences
- Token economy systems (earning rewards)
- Time-out for misbehavior
- Daily report cards
- Structured routines
- Immediate consequences (ADHD = “now” disorder)
Programs:
- Parent-Child Interaction Therapy (PCIT)
- Triple P (Positive Parenting Program)
- Incredible Years
Behavioral Classroom Interventions:
Teacher Strategies:
- Preferential seating (front, away from distractions)
- Frequent breaks
- Breaking tasks into smaller steps
- Immediate feedback
- Daily report card communication with parents
- Behavior charts with rewards
- Extra time for tests
- Reduced homework load
Behavioral Therapy for Adolescents/Adults:
- Skills training (organization, time management)
- Problem-solving strategies
- Self-monitoring techniques
- Cognitive-behavioral therapy
Psychoeducation
For Individual:
- Understanding ADHD
- How it affects them specifically
- Medication education
- Self-advocacy skills
For Family:
- ADHD education
- Realistic expectations
- Strengths-based approach
- Reducing blame and frustration
For Teachers:
- ADHD characteristics
- Effective classroom strategies
- Collaboration with parents
Educational Interventions
Special Education Services (if significant impact):
- IEP (Individualized Education Plan): If meets criteria for special education
- 504 Plan: Accommodations without special education
Common Accommodations:
- Extended time on tests
- Reduced distractions (quiet room)
- Frequent breaks
- Note-taking assistance
- Preferential seating
- Breaking assignments into parts
- Extra set of books at home
- Organizational aids (checklist, planner)
Organizational Support:
- Planners and checklists
- Color-coding systems
- Folders for each subject
- Routine and structure
- Homework tracking systems
Cognitive Training
Working Memory Training:
- Computer-based programs (Cogmed)
- Mixed evidence on effectiveness
- May help working memory but doesn’t generalize to ADHD symptoms
Neurofeedback:
- Training brain waves
- Controversial; limited evidence
- Time-consuming and expensive
Executive Function Training:
- Teaching planning, organization, time management
- More promising than working memory training
Lifestyle Interventions
Exercise:
- Regular physical activity helps symptoms
- Especially aerobic exercise
- Helps with attention, mood, sleep
- Should be part of treatment plan
Sleep:
- Consistent sleep schedule
- Adequate sleep crucial
- Sleep problems common; address them
- Screen time limits before bed
Diet:
- Balanced, nutritious diet
- Regular meals (important with medication)
- Omega-3 supplements (modest benefit)
- Limit caffeine
- Note: Elimination diets (removing foods) have minimal benefit for most
Structure and Routine:
- Predictable daily schedule
- Visual schedules
- Consistent rules and expectations
- Organized environment
Technology and Apps
Helpful Tools:
- Reminder apps
- Task management apps (Todoist)
- Time timers
- Focus apps (block distractions)
- Organizational apps
Coaching and Support
ADHD Coaching (especially for adults):
- Goal-setting
- Accountability
- Strategy development
- Problem-solving
Support Groups:
- CHADD (Children and Adults with ADHD)
- Parent support groups
- Adult ADHD groups
- Connection and shared strategies
Treatment for Different Ages
Preschool (ages 4-5):
- Behavioral parent training first-line
- Medication if severe and behavioral interventions insufficient
- Structure and routine at home
School-Age:
- Medication + behavioral interventions most effective
- School accommodations
- Parent training
- Social skills training if needed
Adolescents:
- Continue medication if helpful
- Organizational skills training
- Driving safety considerations
- Transition planning
- Address self-esteem issues
Adults:
- Medication often helpful
- CBT for coping strategies
- Organizational coaching
- Career counseling
- Relationship therapy if needed
Treatment Effectiveness
MTA Study (Multimodal Treatment of ADHD - landmark study):
- Medication alone: Very effective
- Medication + behavioral therapy: Best outcomes
- Behavioral therapy alone: Less effective than medication but still helpful
- Community care: Least effective
Conclusion: Medication is most effective for core symptoms; combined treatment best for overall functioning
Long-Term Management
ADHD is Chronic:
- Requires ongoing treatment
- Symptoms may change over time
- Hyperactivity often decreases with age
- Inattention and executive function problems persist
- Treatment needs change across lifespan
Prognosis:
- With treatment: Can succeed academically, occupationally, socially
- Without treatment: Higher risk of academic failure, job problems, accidents, substance abuse
- Early intervention improves outcomes
- Many adults manage successfully with appropriate support
What Doesn’t Work
Insufficient Evidence or Ineffective:
- Sugar elimination (myth)
- Megavitamins
- Chiropractic adjustment
- Vision therapy
- Auditory training
- Herbal supplements (most)
- Punishment alone (worsens behavior)
Key Points for Exams
Causes:
- Highly genetic (70-80% heritability)
- Brain differences (prefrontal cortex, basal ganglia)
- Dopamine and norepinephrine dysregulation
- Prenatal factors are risks, not direct causes
- NOT caused by parenting, sugar, or screens
Treatment:
- Medication (stimulants) most effective for core symptoms
- Behavioral parent training evidence-based
- Multimodal treatment (medication + behavioral + school support) best
- School accommodations important (IEP or 504)
- Psychoeducation for all involved
- Exercise, sleep, structure beneficial
- Coaching and organizational strategies helpful
- Treatment needed long-term
- Prognosis good with appropriate treatment