Table 2. Main Results Mapped to the 5-Question Framework^a.

Type of evidence (No. of studies)	Theme (No. of studies)	Subtheme (No. of studies)	Main outcomes (No. of studies)
Question 1. Is there potential for increased diagnosis (n = 104 studies)
Prevalence variations (68)	By subpopulation (48)	Sex (25)	Lower diagnosis in girls than boys (23)5,6,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53 Symptomatic girls less likely to be diagnosed (2)54,55
		SES or insurance status (21)	Higher diagnosis in lower SES (13)5,6,35,36,39,43,45,46,49,53,56,57,58 Higher diagnosis in higher SES (2)59,60 Higher diagnosis in public vs private health insurance (5)5,41,53,58,61 Lower diagnosis in no vs any health insurance (7)5,53,54,58,62,63,64 No association of insurance status with diagnosis in hypothetical scenario (1)55
		Race/ethnicity (21)	Lower diagnosis in Black and Hispanic vs White youths (14)6,35,36,37,41,42,48,49,53,56,62,63,65,66 Lower diagnosis in White vs Black youths (4)39,51,52,67 Lower diagnosis in non-English-speaking and migrant youths (3)35,36,45 No association of race/ethnicity with diagnosis in hypothetical scenario (1)55
		Relative age (12)	Youngest children in class more likely to be diagnosed (11)22,68,69,70,71,72,73,74,75,76,77 No difference in diagnosis probability by relative age (1)78
		Location/region (8)	Large variations in diagnosis by region (8)6,33,35,36,39,46,56,59
		Other (1)	Higher diagnosis and reported symptoms in larger classes (1)42
	By diagnosis (20)	Diagnostic criteria (20)	Broadening of criteria associated with increases in potential cases in comparisons between any DSM version and/or ICD-10 (18)10,20,52,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93 Broadening of age of onset associated with minimal increases in potential cases (2)94,95
Reservoir (44) attributed to	Medicalization (3)	Behavioral problems (3)	Society’s decreasing tolerance for different behavior associated with increased range of behavior diagnosed as abnormal (2)57,96 Mental health professionals from China and Indonesia rating same attention difficulties higher than mental health professionals from US and Japan (1)97
	Phenotype changes (5)	Trends over time (5)	No increase in clinically significant symptoms (4)1,21,98,99 Increase in youths with clinically significant symptoms (1)100 Increase in subthreshold symptoms (1)1
	Diagnostic inaccuracy (16) associated with	Over- and underdiagnosis (16)	Potential over- and underdiagnosis occurring (6)11,64,65,101,102,103 Potential underdiagnosis attributed to false-negatives (5)1,21,38,104,105 Potential overdiagnosis attributed to false-positives (5)54,93,100,106,107
	Spectrum of disorder (22) indicated by subtheme	Implications of extent of symptoms over time (13)	Continuous association between increasing symptoms and increased risk of various later adverse outcomes (13)108,109,110,111,112,113,114,115,116,117,118,119,120
		Subthreshold prevalence (8)	Many youths with subthreshold symptoms (6)108,109,110,114,115,121 Percentage of youths with symptoms decreases with age (2)122,123
		Verification of dimensional structure (7)	Inattention, hyperactivity, and impulsivity problems exist on a spectrum with ADHD at the end (7)119,124,125,126,127,128,129
Question 2. Has diagnosis actually increased? (n = 45 studies)
Diagnosis (45)	Trend over time (45) indicated by subtheme	Change in prevalence (30)	Increasing trend (27)3,5,21,34,39,41,44,47,50,61,66,74,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144 until early 2000s (3)33,60,145
		Change in incidence (12)	Increasing trend (11)2,3,40,43,44,140,142,146,147,148,149 until 2007 (1)60
		Change in lifetime prevalence (12)	Increasing trend (11)1,2,5,6,21,36,37,40,53,56,150 Stagnant in adolescents and increasing in children (1)58
Question 3. Are additional cases subclinical or low risk? (n = 25 studies)
Severity of disorder (17) indicated by theme	Impairment levels (11) indicated by subtheme	Change in adverse outcomes over time (2)	Decreasing problems with increasing ADHD group (1)100 Reduction in hospital visits in medicated children decreasing with increasing group of youths with ADHD (1)150,b
		Difference in adverse outcomes by diagnostic criteria (9)	Broadening of diagnostic criteria and increasing of ADHD group associated with less impairment (5)79,85,86,88,93 Reduction in symptoms and impairments in medicated children decreasing with broadening of ADHD criteria (1)151,b Sample size too small to detect differences (4)84,87,94
	Symptom severity (6) indicated by subtheme	Trend over time (3)	Severity proportions stable (1)132 Larger increase in moderate/severe cases (2)5,138
		Severity proportions (2)	Proportion of youths with severe ADHD being low (2)36,152
		Diagnostic criteria (1)	No difference in severity between late and early-onset cases (1)92
Level of symptoms (8)	Clinically significant symptom prevalence (8) by	Change over time (8)	Prevalence estimates of symptomatic ADHD remaining steady or slightly decreasing (6)1,21,90,91,98,99 Relative age effect increasing in later birth cohorts (2)70,75
Question 4. Have some additional cases been treated? (n = 83 studies)
Medication (83)	Trend over time (83) indicated by subtheme	Prevalent treatment rate (58)	Increasing trend (55)2,5,34,39,40,50,58,74,133,136,141,142,143,150,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191,192,193 Decreases in those younger than 6 years and increases in those older than 6 years (2)194,195 Mostly decreasing trend (2)134,163
		Incident treatment rate (9)	Increasing trend (5)142,166,175,196,197 Stable or variable rate (4)172,198,199,200
		Medication use (11)	Increasing trend (10)50,201,202,203,204,205,206,207,208,209 until 2010 (1)210
		Consultations in which ADHD medication is prescribed (10)	Increasing trend (9)41,47,132,135,139,144,145,211,212 Increasing trend until 2004 in those younger than 6 years (1)213
Question 5a. Might harms outweigh benefits of diagnosis? (n = 31 studies)
Potential benefits of diagnosis (15)	Empowered (14) through	Explanation for problems (11)	Increased legitimacy and validation (5)57,214,215,216,217 Increased understanding, sympathy, and reassurance (8)215,216,217,218,219,220,221,222 Decreased guilt, blame, failure, and anger (6)57,214,215,219,222,223
		Increased control (6)	Decreased uncertainty; feeling of identity and belonging (3)215,218,223 Increased self-esteem and confidence (3)215,218,220 Expectation of solution (4)214,215,218,222
	Enabled (10) to	Support (10)	Increased ability to seek, receive, and accept support (10)57,96,214,215,216,217,219,220,222,223
Potential harms of diagnosis (29)	Disempowered (22) through	Excuse for problems (15)	Decreased responsibility for behaviors and problems (6)96,214,216,220,224,225 Increased deflection from underlying problems (3)57,214,215 No meaningful benefit from diagnosis or no change (10)96,103,216,218,220,222,226,227,228,229
		Loss of control (15)	Associated with control and manipulation by others (4)96,214,220,223 Increased passiveness and hopelessness (3)215,216,222 Self-fulfilling prophecy: perceived inability to change or achieve (by self or others) associated with exclusion and fewer opportunities (9)64,215,217,230,231,232,233,234,235,b
	Stigmatization (14) through	Permanent label and identity (14)	Enhanced prejudice, stereotypes, and judgment (14)215,216,217,218,220,222,225,230,232,236,237,238,239,240 Increased feelings of isolation, exclusion, and shame (3)216,220,225
Question 5b. Might harms outweigh benefits of treatment (n = 120 studies)
Outcomes of pharmacological treatment (120)	Academic (19)	Cognitive and motor functioning (4)	Improvements in commission errors only; all others unchanged (1)241 Favorable outcomes in several aspects of cognition (1)242 and motor skills (1)243 No change after washout period (1)228
		Academic performance (15)	Worse educational outcomes in treated vs rest of the population (1)244 No treatment effect (3)245,246,247 Some small favorable outcomes in treated vs untreated youths (6)248,249,250,251,252,253 Substantial improvement in treated vs untreated or less treated youths (2)254,255 Decrease in academic outcomes after increased medication treatment (1)256 Potential harmful outcome, especially in youths with less severe symptoms (1)64,b Medication treatment only beneficial for youths with more severe symptoms (1)233,b
	Accidents (12)	ED use and hospital admissions (5)	Fewer hospital contacts in treated vs untreated youths, but outcomes smaller in later, larger diagnosed and treated cohorts (1)150,b No change in hospital contacts in treated vs untreated periods and youths (2)257,258 Fewer hospital contacts during treated vs untreated periods (2)257,259 Worse health outcomes in treated vs rest of the population (1)244
		Injuries and poisoning (8)	Lower risk of injuries in treated vs untreated periods (3)259,260,261 and youths (2)262,263 No change in injuries (1)264 or MVAs (1)265 during treated vs untreated periods Increase in unintentional poisonings with ADHD medication (1)266
	Cardiovascular (8)	Blood pressure and heart rate (2)	No association of treatment with blood pressure (2)267,268 but with heart rate (1)268
		Safety (6)	No association of treatment with severe cardiovascular events (3)269,270,271 Increased risk of arrhythmia (1)272 or any serious cardiac event (1)273 Not enough statistical power to detect small differences (3)269,270,274
	Efficacy (30)	Symptom reduction (30)	Substantial short-term symptom reduction for many (24)196,241,247,275,276,277,278,279,280,281,282,283,284,285,286,287,288,289,290,291,292,293,294,295 No symptom improvement after 48-hour washout period (1)296 No long-term difference in treated vs untreated youths (3)245,297,298 Individuals with more severe symptoms at baseline showed greatest treatment response in the long term (5 years) (1)299,b
	Physical (14)	Activity (2)	Lower levels of physical activity in treated vs untreated periods (1)300 and youths (1)301
		Height (12) and weight (5)	Growth delay (2)302,303 and decreased growth (6)297,304,305,306,307,308 or weight (3)304,305,308 No change observed and substantial heterogeneity (5)267,301,303,309,310
	Psychological (20)	Other (2)	Increased risk of psychosis (1)311 and tics (1)312
		Substance abuse (12)	No association of treatment with later substance abuse (4),313,314,315,316 reduced risk (5),317,318,319,320,321 and increased risk of stimulant abuse (1)322 Prescription stimulant misuse or diversion in youths with or without ADHD (2)323,324
		Suicidal behavior (6)	No association of treatment with risk of suicidal behavior (2),325,326 reduced risk (3),327,328,329 and increased risk (1)330
	Social and emotional (11)	Emotional (3)	Increased risk of irritability with amphetamine treatment (1)331 Mixed outcomes for various emotional behaviors with stimulant treatment (1)332 Decrease in happiness after increased medication treatment (1)256
		Criminal behavior (3)	Reduced risk of conviction and incarceration in treated vs untreated periods (1)333 No change in risk of receiving driving citation for treated vs untreated periods (1)265 Reduced risk of being charged with a crime in treated vs untreated youths, but effects were smaller in later, larger diagnosed and treated cohorts (1)150,b
		Social impairment (2)	Little change in social impairment in treated vs untreated period (1)246 Potentially relevant improvements in some domains in treatment vs placebo group (1)334
		Quality of life (4)	Small short-term improvements in quality of life (3)334,335,336; no impact (1)337
	Tolerability (29)	Adverse events (25)	Low occurrence of mild AEs (2)196,277 Relatively common mild or moderate AEs (16)276,278,280,281,286,289,291,292,294,295,299,338,339,340,341,342 Young children more vulnerable to AEs (2)295,343 Reporting of AEs unsatisfactory (6)282,291,294,344,345,346 Serious AEs rare but difficult to determine from reported data (5)287,338,340,345,346
		Discontinuation (6)	Moderate to high discontinuation rates (20%-44%) (4)290,341,347,348 Discontinuation similar to placebo group or low-quality evidence (2)275,285
	Various (8)	Mixed (8)	50% of various outcomes reported some benefits of treatment (1)349 Reduced risk of various outcomes (2)350,351 Lack of methodologically sound research on which to base decisions (1)352 Longer treatment duration indicated better outcomes for various domains (1)353 No long-term treatment effect for various functioning outcomes (3)354,355,356

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; AE, adverse event; DSM, Diagnostic and Statistical Manual of Mental Disorders; ED, emergency department; ICD-10, International Statistical Classification of Diseases and Related Health Problems, Tenth Revision; MVA, motor vehicle accident; SES, socioeconomic status.

^aFull main results are presented in eAppendix 6 in Supplement 1.

^bItems refer specifically to the benefits and harms for young people with less severe ADHD behaviors.