Download An Economic and Policy Analysis of the Market for Methylphenidate

ADHD & Stimulants
1
Background & Significance
So what? What is the significance of ADHD and psychostimulants?
– ADHD is the most commonly diagnosed behavioral disorder in
children, making up more than 50% of all child psychiatric diagnoses
– 75-85% of children diagnosed with ADHD are prescribed
psychostimulant drugs (e.g., Ritalin, Adderall, Dexedrine, Concerta)
– the U.S. population consumes 90% of the world’s production of
psychostimulants
– school-age children in the U.S. consume 4 times more psychiatric
medication than children in the rest of the world combined
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Background & Significance
So what? What is the significance of ADHD and psychostimulants? cont’d . . .
– an estimated 3-5% of school-age children have the disorder (NIH
Consensus Statement, 1998); other estimates 4-12% (Vanderbilt, MUSC);
(1.5-to-6 million kids, 1-to-3 students in every classroom in the U.S.)
– ADHD prevalence estimates from actual community studies range from as
low as 1.7% (Calif. Bay Area) to as high as 20% (military bases near Virginia Beach)
– rates of psychostimulant use vary as much as 3-fold between states and
10-fold within them (Rappley et al., 1995; Wennberg & Wennberg, 2000; Zito et al., 1997)
– At the peak age for psychostimulant use, 11, almost 1 in every 10 boys in
the U.S. uses these drugs (Cox et al., Journal of Pediatrics, February 2003).
– big $$: approximately $1.2 billion spent in 2001 on ADHD related drugs
(new potential growth markets: pre-schoolers and adults)
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History of ADHD & Stimulants: “Moral Deficiency”
"Passionate, deviant, spiteful, and lacking inhibitory volition."
• That's how one pediatrician, GEORGE FREDERICK STILL,
described children with symptoms of attention deficit
hyperactivity disorder (ADHD). The year was 1902, and Still
puzzled over his young patients in The Lancet.
• What was their disorder, exactly--and what caused it?
• Alfred Tredgold: 1922 and “mental defectives”
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History of ADHD & Stimulants: Tredgold (1922)
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History: Influenza 1918 & Bradley Home 1930’s
• “encephalitis lethargica”
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History: Rise of Special Education & NIMH 1950s-1970s
• NIMH begins pediatric psychopharmacology research in 1958
• Ritalin first approved for use in 1961
• Conners & Eisenberg, 1963, 1st article advocating Ritalin
different era for child research
• “MBD” minimal brain dysfunction in DSM-II (1968)
• 1970: Washington Post: “Omaha Pupils Given ‘Behavior Drugs’”
• 1975: Schrag & Divoky’s The Myth of the Hyperactive Child and Other
Means of Child Control
• 1980: DSM-III “Attention Deficit Disorder” ADD
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DSM-IV Diagnostic Criteria for ADHD
Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association)
Either (1) or (2)
(1). 6 (or more) of the following 9 symptoms of inattention have persisted for at least 6 months to a degree that
is maladaptive and inconsistent with developmental level:
Inattention
(a) often fails to give close attention to details or makes careless mistakes in schoolwork,
work, or other activities
(b) often has difficulty sustaining attention in tasks or play activities
(c) often does not seem to listen when spoken to directly
(d) often does not follow through on instructions and fails to finish schoolwork, chores, or
duties in the workplace (not due to oppositional behavior or failure to understand instructions)
(e) often has difficulty organizing tasks and activities
(f) often avoids, dislikes, or is reluctant to engage in tasks that require sustained mental effort
(such as schoolwork or homework).
(g) often loses things necessary for tasks or activities (e.g. toys, school assignments, pencils,
books, or tools)
(h) is often easily distracted by extraneous stimuli
(i) is often forgetful in daily activities
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DSM-IV Diagnostic Criteria for ADHD
Diagnostic and Statistical Manual of Mental Disorders, 4th edition (American Psychiatric Association)
(2). 6 (or more) of the following 9 symptoms of hyperactivity-impulsivity have persisted for at least 6 months to
a degree that is maladaptive and inconsistent with developmental level:
Hyperactivity
(a) often fidgets with hands or feet or squirms in seat
(b) often leaves seat in classroom or in other situations in which remaining seated is expected
(c) often runs about or climbs excessively in situations in which it is inappropriate (in adolescents or
adults, may be limited to subjective feelings of restlessness)
(d) often has difficulty playing or engaging in leisure activities quietly
(e) is often "on the go" or often acts as if "driven by a motor"
(f) often talks excessively
Impulsivity
(g) often blurts out answers before questions have been completed
(h) often has difficulty awaiting turn
(i) often interrupts or intrudes on others (e.g. butts into conversations or games)
ADHD’s inherent subjectivity lends itself to criticisms of being a convenient social construct (for
“medicalizing” and medicating annoying behavior) and fuels the controversy over the disorder…
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The Diagnostic Triangle with the Child/Adolescent in the Middle
Teachers
- usually 1st to identify ADHD, along with other school personnel
- increasingly faced with external performance pressures (e.g., achievement/outcome-based tests)
- often spend the most time with children in a structured environment
Clinicians
Parents
- no indep. medical test
- ultimate decision-makers
- etiology unknown
- time constraints
- concern about side-effects/stigma
- most concerned about the child
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The Diagnostic Triangle with the Child/Adolescent in the Middle
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Four Aspects to the Controversy Over ADHD/Ritalin
1.
Allegation: ADHD is not a real disorder and could be part of a larger
feminist conspiracy to make little boys more like little girls.
etiology is unknown and no independent medical test for diagnosing ADHD;
biology vs. environment debate
2.
Allegation: ADHD is a conspiracy on the part of public schools to
warehouse kids instead of effectively teaching and disciplining them.
initial identification of ADHD is often by teachers or other school personnel in academic settings
3.
Allegation: Ritalin is really “kiddie cocaine” and parents who give their
kids these kinds of drugs are simply doping up their problem children.
psychostimulants are powerful, potentially addictive drugs susceptible to personal abuse and illegal diversion
(classified as Schedule II drugs by the DEA, along with Oxycontin and morphine)
4.
Allegation: ADHD is over-diagnosed and psychostimulants are overprescribed across the country.
number of ADHD diagnoses and psychostimulants Rx’s increased dramatically in the 1990s
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Diagnostic and Prescribing Trends
• 400-500% increase in ADHD diagnoses since 1991
– 1991: 800,000 to 950,000 children diagnosed with ADHD
– 2001: 4 to 4.25 million children diagnosed with ADHD
• 800-900% increase in psychostimulant use since 1991
– 1991: 2 million psychostimulant prescriptions
– 2001: 21 million psychostimulant prescriptions
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Diagnostic and Prescribing Trends: American Exceptionalism
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Increased Public Awareness During Clinton Years
“As many of you know, the Journal of the American Medical Association recently
reported that the number of preschoolers, ages 2-4 who are taking psychotropic drugs
increased dramatically from 1991 to 1995 [200,000-300,000 or 1.5% of the total]. We
know that the increase for Ritalin alone was 150 percent, and the use of anti-depressants
increased over 200 percent. Now I am no doctor, as is obvious, but I am a parent and I
have been a longtime children’s advocate. And these findings concern me. I know they
concern Dr. Hyman [Director, NIMH], Secretary [Donna] Shalala and countless other
experts.”
The White House -- March 20, 2000
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New State Policies Regarding Psychostimulants & School Staff
Connecticut, Minnesota, Wisconsin, New York, New Jersey, Utah, Arizona, Virginia
VIRGINIA CHAPTER 314
An Act to amend the Code of Virginia by adding a section numbered 22.1-274.3,
relating to certain medication recommendations by school personnel.
[H 90]
•
•
•
•
•
[Approved April 1, 2002 ]
Be it enacted by the General Assembly of Virginia:
1. That the Code of Virginia is amended by adding a section numbered 22.1-274.3 as follows:
§ 22.1-274.3. Policies regarding medication recommendations by school personnel.
The Board of Education shall develop and implement policies prohibiting school personnel from recommending the use of
psychotropic medications for any student. Such policies shall not prohibit school health staff, classroom teachers or other
school professionals from recommending that a student be evaluated by an appropriate medical practitioner, or prohibit school
personnel from consulting with such practitioner, with the written consent of the student's parent.
For the purposes of this section, "psychotropic medications" means those medications the prescribed intention of which is to
alter mental activity or state, including, but not limited to, antipsychotic, antidepressant, and anxiolytic medication and
behavior-altering medication.
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Current Controversies I
Wall Street Journal (November 8, 2004)
“Pressed to Do Well On Admissions Tests, Students Take Drugs”
Stimulants Prescribed for Attention Disorders Find New Unapproved Use
By NICHOLAS ZAMISKA, Staff Reporter
BETHESDA, Md. -- On the morning he was to take the SAT last March, a 17-year-old
senior at Bethesda-Chevy Chase High School in suburban Washington went looking for a
bottle of pills. His score on practice tests had been too low and, with his sights set on an Ivy
League college, he needed a miracle. Or, friends suggested, Adderall.
He grabbed a tiny blue pill from his little brother's prescription stash and swallowed it two
hours before the test. Despite some jitters when he took the test that he attributes to the
drug -- a stimulant prescribed for attention deficit hyperactivity disorder, or ADHD -- he
scored 200 points better than he had on a previous test. In an interview recently, he
credited the drug with keeping him alert and confident: "It just felt like I was on top of my
game. I knew I was going to get the questions right.“
UofR sample: 15-35% use stimulants illicitly; Bates College: 35%
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Current Controversies II
American College of Neuropsychopharmacology’s Annual Meeting (2004)
McLean Hospital and Harvard Medical School researchers
William Carlezon and Nancy Anderson
Finding: “Long-term use of Ritalin and similar drugs can permanently alter a
developing child’s brain and may lead to increased likelihood of depression in
children who do not have ADHD.”
Dr. Carlezon and Dr. Andersen exposed normal rats to twice-daily doses of Ritalin
during a period that is equivalent to approximately 4-12 years of age in humans.
Drs. Carlezon and Andersen found that the animals had a reduced ability to experience
pleasure and reward. In addition, they found that the animals exposed to Ritalin
during pre-adolescence were more prone to express despair-like behaviors in
stressful situations (such as swim tests) as adults.
* Overall, the animals showed more evidence of dysfunctional brain reward
systems and depressive-like behaviors in adulthood.
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Public Policy Implications & Questions
• Over-diagnosis of ADHD (Are we “pathologizing” childhood?)
Does the U.S. have a monopoly of wisdom on diagnosing and treating ADHD?
• Over-use of psychostimulants (public health issue)
waste of limited resources; Society for Neuroscience findings, 2001
-------------------------------------------------------------------• Under-diagnosis of ADHD (public health/education issues)
Children with unmet mental health needs are more likely to suffer academically and developmentally.
• Under-use of psychostimulants (public health/education issues)
Studies show that untreated ADHD can lead to increased self-medication and drug addiction.
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Main Limitation of Existing Studies: Generalizability
Most of what we know about ADHD/psychostimulants is based
on local community studies of children with ADHD and
psychostimulant use.
Thus, to date we have relied primarily on massive meta-analyses
and the NIH funded Multimodal Treatment Study of ADHD
(MTA) to cobble together a national profile of both ADHD and
psychostimulant use.
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On the Road to Model Building . . .
1st place to start: constructing a national profile of the ADHD
population and determine if there are any independent sociodemographic predictors of the disorder.
A national profile is our first “value added” contribution to the
knowledge base of ADHD and psychostimulants.
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A National Profile of Children With ADHD
Data Set: National Health Interview Survey (NHIS), 1999
-
nationally representative, cross-sectional health survey conducted
jointly by the National Center for Health Statistics (NCHS) and the
Centers for Disease Control & Prevention (CDC)
-
sample size: 37,573 households; 97,059 persons in 38,171 families
-
child component: 12,910 children less than 18 years old;
response rate, 90.8%
-
survey question: “Has a doctor or a health professional ever told you that
[child’s name] has ADHD?”
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Characteristics of Children With ADHD
Adjusted Odds Ratios for Prevalence Estimates of ADHD from the NHIS
# Odds ratios adjust for all other predictor variables in the table
Variable
Demographic
Male
Female
Age (mean)
Birth Weight (mean in ounces)
White
Black
Asians
Geographic Region
Northeast
Midwest
South
West
Estimated
Number
of Cases
Odds Ratio
for
Prevalence#
Odds
Ratio
S.E.
P
value
2,065,833
659,266
n.a
n.a.
2,323,208
302,828
99,063
1.000
0.315
1.139
0.993
1.000
0.588
0.506
-0.042
0.013
0.003
-0.105
0.144
-> 0.000
> 0.000
0.010
-0.003
0.018
377,392
767,461
1,168,070
412,176
0.845
1.288
1.629
1.000
0.188
0.218
0.270
--
0.449
0.137
0.004
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Characteristics of Children With ADHD
# Odds ratios adjust for all other predictor variables in the table
Variable
Family
# of persons in the family (mean)
Relationship with Parents
Mother: biological
Mother: step, adoptive, foster, none
Parents Present
Mother and Father
Mother, no Father
Parents’ Marital Status
Married
Divorced/Separated/Never
Married/Widowed
Mother’s Highest Level of Educ.
Less Than College
College Degree or More
Family’s Out-of-Pocket Medical Costs
Zero
$1-$2,999
$3,000+
Estimated
Number
of Cases
Odds Ratio
for
Prevalence#
Odds
Ratio
S.E.
P
value
n.a.
0.754
0.044
> 0.000
2,544,518
180,581
0.415
1.000
0.089
--
> 0.000
--
1,844,563
880,536
1.606
1.000
0.887
--
0.391
--
1,856,302
868,797
0.487
1.000
0.270
--
0.187
--
2,250,396
474,703
1.000
0.759
-0.119
-0.080
187,056
2,336,726
201,317
1.000
1.420
1.602
-0.328
0.515
-0.131
0.143
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NHIS Dataset
Conditional Probability of a Child Being Diagnosed with ADHD
0.2000
White Male Child
Male Child w/o Bio Mom
Male Child w/o Dad in House
White Male Child w/o Bio Mom
White Male Child w/o Bio Mom & w/o Dad In House
0.1500
0.1000
0.0500
0.0000
2
3
4
5
6
7
8
Family Size
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Methylphenidate and Amphetamine
Distribution, 2000 (DEA data)
(average = 4,150 grams/100,000 individuals)
grams/per 100,000 Individuals
0 to 1,600
Low
1,600 to 3,150 Below Average
3,150 to 5,150 Average
5,150 to 6,750 Above Average
6,750 to 8,350 High
8,350 to 11,000 Extremely High
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(4.6%)
(25.5%)
(43.5%)
(19.6%)
(4.9%)
(1.8%)
Childhood
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