Presentation on theme: "Attention-Deficit Hyperactivity Disorder By Chris Golner April 19, 1999 Biochemistry/Molecular Biology Seminar."— Presentation transcript:
Attention-Deficit Hyperactivity Disorder By Chris Golner April 19, 1999 Biochemistry/Molecular Biology Seminar
ADHD of all U.S. school-age children are estimated to have this of the entire U.S. are 3 to 6 times more likely to have ADHD than are least 50% of ADHD sufferers have another diagnosable mental disorder.
of and Diagnosis: DSM-IV Õ
History of Minimal Brain 1900s: Minimal Brain Attention-Deficit Disorder Õ With or Without Attention Deficit Hyperactivity ADHD Õ Primarily Inattentive Õ Primarily Hyperactive Õ Combined Type
Diagnosing ADHD: Inattentiveness: Has a minimum of 6 symptoms regularly for the past six months. Symptoms are present at abnormal levels for stage of development ' Lacks attention to detail; makes careless mistakes ' has difficulty sustaining attention ' doesn’t seem to listen ' fails to follow through/fails to finish projects ' has difficulty organizing tasks ' avoids tasks requiring mental effort ' often loses items necessary for completing a task ' easily distracted ' is forgetful in daily activities
Diagnosing ADHD: Impulsivity: ' Fidgets or squirms excessively ' leaves seat when inappropriate ' runs about/climbs extensively when inappropriate ' has difficulty playing quietly ' often “on the go” or “driven by a motor” ' talks excessively ' blurts out answers before question is finished ' cannot await turn ' interrupts or intrudes on others Has a minimum of 6 symptoms regularly for the past six months. Symptoms are present at abnormal levels for stage of development
Diagnosing ADHD: Criteria: ' Symptoms causing impairment present before age 7 ' Impairment from symptoms occurs in two or more settings ' Clear evidence of significant impairment (social, academic, etc.) ' Symptoms not better accounted for by another mental disorder
Problems of of evaluations--presence of symptoms usually given by teacher or by Szatmari et al (1989) showed that the number of diagnosed cases of ADHD decreased 80% when observations of parent, teacher and physician were used rather than just one in females more subtle---leads to underdiagnosis
ADHD and the arousal of the Nervous blood flow to prefrontal cortex and pathways connecting to limbic system (caudate nucleus and scan shows decreased glucose metabolism throughout brain Comparison of normal brain (left) and brain of ADHD patient.
ADHD and the Brain of ADHD symptoms to those from injuries and lesions of frontal lobe and prefrontal of ADHD patients show: ' Smaller anterior right frontal lobe ä abnormal development in the frontal and striatal regions ' Significantly smaller splenium of corpus callosum ä decreased communication and processing of information between hemispheres ' Smaller caudate nucleus
What causes cause of these differences is still unknown; there is much conflicting data between evidence of genetic theory: Catecholamine neurotransmitter dysfunction or imbalance ä decreased dopamine and/or norepinephrine uptake in brain ä theory supported by positive response to stimulant study indicates possible lack of serotonin as a factor in mice
Scientific American Http//www.sciam.com/1998/0998issue/0998barkely.html#link1 Dopamine in the Brain
Genetic Linkages to studies by Stevenson, Levy et al, and Sherman et al indicate an average heritability factor et al reported a 57% risk to offspring if one parent has genes ä DA type 2 gene ä DA transporter gene (DAT1) ä Dopamine receptor (DRD4, “repeater gene”) is over-represented in ADHD patients
is most likely affects the post-synaptic sensitivity in the prefrontal and frontal region of cortex affects executive functions and functions include working memory, internalization of speech, emotions, motivation, and learning of behavior
of individual @Clonidine
mechanism activity level of the CNS by decreasing fluctuations of activity or lowering threshold needed for in structure to NE and DA, and may mimic their least 75% have positive response with single respond well to stimulant methylphenidate, dextroamphetamine and pemoline
a piperidine derivative commonly known as Ritalin believed to act as dopamine agonist in synaptic frontal- striatal (5-20 mg) must be adjusted to each orally, 2-3 times a day as effects start within 1/2 hour to hour after ingestion, peaking at 1 and 3 comes in Sustained-Release form, whose effects last approximately twice as long.
Effects of arousal of CNS and cerebral blood social heart rate and blood little or no abuse potential
Side ' decreased appetite ' insomnia ' behavioral rebound ' head and stomach thought to cause temporary height and weight ' anxiety/ depression ' ' tics (Tourette’s Syndrome) ' overfocussing ' liver problems or rash (Pemoline only)
can persist into adulthood, but usually symptoms gradually it persists into adulthood, it usually requires ongoing treatment and will develop another disorder (especially learning disability, ODD, depression, and/or conduct treatment: ä antisocial and deviant behavior ä increased rates of divorce, moving violations, incarceration, and institutionalization
References Barkley, R. Attention-Deficit Hyperactivity Disorder, 2 nd Ed. New York: Guilford Press pp. Shaywitz, B. and Shaywitz, S. Attention Deficit Disorder Comes of Age: Toward the 21 st Century. Austin, TX: Hammill Foundation pp. Rie, H.E. and Rie, E.D., Eds. Handbook of Minimal Brain Dysfunctions: A Critical View. New York: John Wiley & Sons pp. Faigel, H. Attention Deficit Disorder: A Review. J. of Adolesc. Health, Mar 1995 Vol. 16: Cantwell, D.P. Attention Deficit Disorder: A Review of the Past Ten Years. J. of the Am. Acad. Of Child Adolesc. Psychiatry. 1996, Vol 35: Seideman, L., Biederman, J., and Faraone, S.V. A Pilot Study of Neuropsychological Function in Girls with ADHD. J. of Am. Acad. of Child Adolesc. Psychiatry, Vol. 36:
References Levy, F., Hay D.A., McStephen, M., Wood, C., and Waldman, I. Attention-Deficit Hyperactivity Disorder: A Category or Continuum? Genetic Analysis of a Large Scale Twin Study. J. of Am. Acad. Of Child Adolesc. Psychiatry, 1997, Vol 36: Sherman, D.K., Iacono, W.G., McGue, M.K. Attention-Deficit Hyperactivity Disorder Dimensions: A Twin Study of Inattention and Impulsivity-Hyperactivity. J. of Am. Acad. Of Child Adolesc. Psychiatry, 1997, Vol 36: Scientific American Online: Ritalin Action on Hyperactivity Explained By New Theory Approaching a Scientific Understanding of what Happens in the Brain in AD/HD Marx, J. How Stimulant drugs May Clam Hyperactivity. Science, 1999, Vol. 283: ULTFORMAT=&fulltext=Attention+Deficit+Disorder&searchid=QID_NOT_SET&FIRSTIN DEX=