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Relevant question
- Are you a hypochondriac? Or do you need to lose an eye before you'll go to the hospital ER??
- Secondhand smoke and exaggeration by health fascists?
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Answer`s (6):
1.
sadie_oyes
Understanding ADHD:
ADHD is a real disorder, despite seemingly widespread beliefs to the contrary. I have met more than one person who snorts with disgust when ADHD is mentioned, saying something like, "In my day, if a kid had too much energy, you told him to run around on the playground for a while. Now they give him drugs!" Other doubters suggest that there are probably more kids with attention problems these days, but it’s because this generation is easily bored due to excess television viewing and permissive parents who buy them too many toys. To make matters worse, ADHD’s high incidence now (compared to its apparent absence a generation ago) gives the diagnosis a faddish feeling.
But all of these impressions are based on inaccuracies. ADHD is not new—it has been identified since the early 20th century. Until 1980, ADHD went by other names such as "restlessness syndrome" or "hyperkinetic impulse disorder." Sophisticated studies tell us that it is not caused by bad parenting, too much television, or playing video games. A large number of studies have examined the relationship of these sorts of social practices and found that they do not cause ADHD (e.g. Anderson, 1996). And further, there does not appear to be anything about American culture in particular that breeds the disorder; research demonstrates that ADHD exists in about the same percentage of children in other cultures (Szatmari, 1992).
ADHD is a medical disorder for which there is very strong scientific evidence. It has three recognized subtypes, predominantly Hyperactive, predominantly Inattentive, and Combined, each of which looks a little different. Kids whose ADHD is predominantly Hyperactive-Impulsive,2 show mostly hyperactive and impulsive symptoms, i.e., they seem to fidget nonstop, they have a hard time playing quietly, and they don’t seem to think before they act. Those with predominantly Inattentive ADHD show more inattentive symptoms, i.e., they don’t seem to listen, they often seem to be daydreaming, and they have trouble organizing tasks. The third group, with Combined ADHD, shows both types of symptoms.
Interestingly, children with ADHD (regardless of subtype) can sustain attention when they find something in the environment of interest, for example a video game or movie, or a building project. The problem comes in controlling their attention; that is, directing and maintaining it when the object itself does not have properties that maintain the child’s interest.
Researchers have a fair idea about at least some of what goes wrong in the brain of a child suffering from ADHD. A brain circuit is affected that involves structures near the center of the brain called the basal ganglia, and part of the prefrontal cortex—the front part of the outer covering of the brain. Brain imaging studies show that these structures are smaller and less active in ADHD sufferers than in non-ADHD control participants (i.e., Giedd et al., 1996; Zametkin et al., 1990). We also know that there are particular problems in the way these brain structures use dopamine, one of the chemicals that nerve cells in the brain use to communicate with one another and that play a crucial role in the basal ganglia and prefrontal cortex.
That’s the biology behind ADHD. But what causes these biological differences? Geneticists have shown that ADHD is one of the most heritable psychiatric diseases known. Heritabilty refers to the extent to which one’s genetic inheritance influences an outcome (i.e., the likelihood of developing ADHD). Some important studies of heritability have examined twins. Of course, twins can be identical (and so share 100 percent of their genes) or fraternal (and so share 50 percent of their genes). Studies show that if one twin has ADHD, then the other is much more likely to have it if the twins are identical than if they are fraternal. Note that the home lives of either identical or fraternal twins are likely to be quite similar (Levy et al., 1997). Thus it is the greater shared genetic component that drives the effect. Further, geneticists have identified several candidate genes that may be the culprit, most of which are implicated in the regulation of dopamine (e.g., Faraone et al., 1997).
How large is the genetic contribution? One way to think about it is to compare the effect of genetics on height and on ADHD: The heritability of ADHD is about 80 percent; the heritability of adult height is about 90 percent. In short, whether or not a child develops ADHD depends largely on his or her genetic inheritance, not the amount of television watched or a particular parenting style.4
This description of the brain basis of ADHD makes it sound as though kids won't just "grow out of it," and indeed, they don't. Kids with ADHD for the most part, but not uniformly, grow up to be adults with ADHD. And as they grow, these kids, if untreated, are at significantly increased risk for a host of problems. They are much more likely than other kids to drop out of school and to have few or no friends. They are also at increased risk for teen pregnancy, drug abuse, clinical depression, and personality disorders.
Diagnosis:
It is not currently possible to diagnose ADHD via genetic testing (as we can, for example, for Huntington’s disease) or by an analysis of the brain’s chemicals. Rather, it is diagnosed via a careful analysis of behavior. A child must show six of nine symptoms in one of the two lists shown below to be diagnosed as either predominantly Inattentive or predominantly Hyperactive-Impulsive. If the child has six or more characteristics from both lists, he or she is diagnosed as Combined. These characteristics are evaluated relative to the child’s peer group. Further, the symptoms must be present for at least a year, they must occur in at least two different settings, they must appear before age 7 (a rule that acknowledges ADHD’s biological basis in the brain, which means the disorder would likely appear by age 7), and they must be severe enough that the child is impaired in major life activities, such as school work or getting along with friends (i.e., the symptoms actually cause problems). Together, these constraints work to protect against unmerited diagnoses. In addition, other possible causes of the symptoms must also be ruled out, e.g., other neurological or psychiatric disorders, a reaction to a stressor such as a chaotic home life, and so on. It may seem suspicious to you that there is not a 100 percent accurate marker for the disorder. But other diseases—for example, Alzheimer’s disease—are likewise diagnosed via a set of symptoms coupled with exclusion criteria.
ADHD is a real disorder, despite seemingly widespread beliefs to the contrary. I have met more than one person who snorts with disgust when ADHD is mentioned, saying something like, "In my day, if a kid had too much energy, you told him to run around on the playground for a while. Now they give him drugs!" Other doubters suggest that there are probably more kids with attention problems these days, but it’s because this generation is easily bored due to excess television viewing and permissive parents who buy them too many toys. To make matters worse, ADHD’s high incidence now (compared to its apparent absence a generation ago) gives the diagnosis a faddish feeling.
But all of these impressions are based on inaccuracies. ADHD is not new—it has been identified since the early 20th century. Until 1980, ADHD went by other names such as "restlessness syndrome" or "hyperkinetic impulse disorder." Sophisticated studies tell us that it is not caused by bad parenting, too much television, or playing video games. A large number of studies have examined the relationship of these sorts of social practices and found that they do not cause ADHD (e.g. Anderson, 1996). And further, there does not appear to be anything about American culture in particular that breeds the disorder; research demonstrates that ADHD exists in about the same percentage of children in other cultures (Szatmari, 1992).
ADHD is a medical disorder for which there is very strong scientific evidence. It has three recognized subtypes, predominantly Hyperactive, predominantly Inattentive, and Combined, each of which looks a little different. Kids whose ADHD is predominantly Hyperactive-Impulsive,2 show mostly hyperactive and impulsive symptoms, i.e., they seem to fidget nonstop, they have a hard time playing quietly, and they don’t seem to think before they act. Those with predominantly Inattentive ADHD show more inattentive symptoms, i.e., they don’t seem to listen, they often seem to be daydreaming, and they have trouble organizing tasks. The third group, with Combined ADHD, shows both types of symptoms.
Interestingly, children with ADHD (regardless of subtype) can sustain attention when they find something in the environment of interest, for example a video game or movie, or a building project. The problem comes in controlling their attention; that is, directing and maintaining it when the object itself does not have properties that maintain the child’s interest.
Researchers have a fair idea about at least some of what goes wrong in the brain of a child suffering from ADHD. A brain circuit is affected that involves structures near the center of the brain called the basal ganglia, and part of the prefrontal cortex—the front part of the outer covering of the brain. Brain imaging studies show that these structures are smaller and less active in ADHD sufferers than in non-ADHD control participants (i.e., Giedd et al., 1996; Zametkin et al., 1990). We also know that there are particular problems in the way these brain structures use dopamine, one of the chemicals that nerve cells in the brain use to communicate with one another and that play a crucial role in the basal ganglia and prefrontal cortex.
That’s the biology behind ADHD. But what causes these biological differences? Geneticists have shown that ADHD is one of the most heritable psychiatric diseases known. Heritabilty refers to the extent to which one’s genetic inheritance influences an outcome (i.e., the likelihood of developing ADHD). Some important studies of heritability have examined twins. Of course, twins can be identical (and so share 100 percent of their genes) or fraternal (and so share 50 percent of their genes). Studies show that if one twin has ADHD, then the other is much more likely to have it if the twins are identical than if they are fraternal. Note that the home lives of either identical or fraternal twins are likely to be quite similar (Levy et al., 1997). Thus it is the greater shared genetic component that drives the effect. Further, geneticists have identified several candidate genes that may be the culprit, most of which are implicated in the regulation of dopamine (e.g., Faraone et al., 1997).
How large is the genetic contribution? One way to think about it is to compare the effect of genetics on height and on ADHD: The heritability of ADHD is about 80 percent; the heritability of adult height is about 90 percent. In short, whether or not a child develops ADHD depends largely on his or her genetic inheritance, not the amount of television watched or a particular parenting style.4
This description of the brain basis of ADHD makes it sound as though kids won't just "grow out of it," and indeed, they don't. Kids with ADHD for the most part, but not uniformly, grow up to be adults with ADHD. And as they grow, these kids, if untreated, are at significantly increased risk for a host of problems. They are much more likely than other kids to drop out of school and to have few or no friends. They are also at increased risk for teen pregnancy, drug abuse, clinical depression, and personality disorders.
Diagnosis:
It is not currently possible to diagnose ADHD via genetic testing (as we can, for example, for Huntington’s disease) or by an analysis of the brain’s chemicals. Rather, it is diagnosed via a careful analysis of behavior. A child must show six of nine symptoms in one of the two lists shown below to be diagnosed as either predominantly Inattentive or predominantly Hyperactive-Impulsive. If the child has six or more characteristics from both lists, he or she is diagnosed as Combined. These characteristics are evaluated relative to the child’s peer group. Further, the symptoms must be present for at least a year, they must occur in at least two different settings, they must appear before age 7 (a rule that acknowledges ADHD’s biological basis in the brain, which means the disorder would likely appear by age 7), and they must be severe enough that the child is impaired in major life activities, such as school work or getting along with friends (i.e., the symptoms actually cause problems). Together, these constraints work to protect against unmerited diagnoses. In addition, other possible causes of the symptoms must also be ruled out, e.g., other neurological or psychiatric disorders, a reaction to a stressor such as a chaotic home life, and so on. It may seem suspicious to you that there is not a 100 percent accurate marker for the disorder. But other diseases—for example, Alzheimer’s disease—are likewise diagnosed via a set of symptoms coupled with exclusion criteria.
2.
Socrates1961
Limited Medical Resources.
3.
J
Surgical Technologists
4.
Richmond C
How about the structure of the finger. It is the coolest system of tendons and ligamints in the body. Check it out.
5.
mushrooman2000
how about the affects of performance enhancing steroids on a persons body. there is plenty of info out there
6.
Jimmy the Cricket
How to make babies safely!!!
