ADD Research
Table of Contents
Early age of psychostimulant treatment and depression
Omega fatty acid supplements showed no benefit for treatment of ADHD
A clue to how stimulants work
Stimulant use by students with ADHD improved their reading and math scores
The effects of medication treatment of ADHD on tics
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Effect of psychostimulant treatment at an early age and depression
Researchers looked at the histories of 75 children with ADHD. About half of them developed depression as the grew older and the other half didn’t. The children whose ADHD was treated with stimulant medication were found to be less likely to develop depression later in life. The research does not give clear answers about the relationship between ADHD treatment in adulthood and depression in adults.
Omega Fatty Acid Supplements Showed No Benefit for Treatment of ADHD
There have been many dietary restrictions and supplements recommended for treatment of ADHD. Currently, omega fatty acids (such as those found in fish oil and flaxseed oil) are being recommended by some for treatment of many psychiatric disorders, ADHD among them. One study compared the addition of two omega fatty acids, linoleic acid and a-linolenic acid, to a placebo (vitamin C.) After seven weeks of daily supplementation the group receiving the omega supplements were compared to the group receiving vitamin C. The researchers found no difference in the two groups’ symptom improvement, implying that these omega supplements are not a beneficial treatment for ADHD. Despite the attractiveness of the omegas (widely available, inexpensive, few to no side-effects), there is as of yet little evidence to recommend their use in ADHD.
A clue to how stimulants work
It is important to know which parts of the brain change when stimulant medication improves a person’s ADD symptoms, as this information may help scientists develop more effective treatments. Brain scans were done on 16 youths with ADD and on 20 youth without ADD. While doing tasks that required self control, brain waves of ADD subjects had a greater amount of unnecessary electrical activity (static) in a part of the brain called the cingulate than did those without ADD Stimulant medication was found to reduce this activity. When it did, the subjects’ minds wandered less.
Stimulant Use by Students with ADHD Improved Their Reading and Math Scores
The reading and math skills of over 8,000 school age children were followed between kindergarten and 6th grade. About 600 of them were found to have ADHD. Those with ADHD who were treated with stimulant medication scored more than 5 points higher on reading tests than the ADHD children who did not get stimulant treatment. Their math scores were also significantly higher, though slightly less so. The longer the treatment lasted, the greater were the effects of the medications were. However, treatment did not close the gap between treated children with ADD and children who did not have ADD. Individualized educational programs also seemed to help those with ADD.
The results of this study must be viewed with caution as data about the diagnosis and treatment were based on parents’ reports, which might not always have been accurate. This ongoing study is being funded by the National Institutes of Health.
Medication Treatment of ADHD and Tics
A review was carried out of nine studies involving 477 children under 18 years of age who had both ADHD and tics to determine whether stimulants make tic symptoms worse and to compare the effectiveness of various medications on ADHD. Most subjects were boys.
The studies examined two stimulants (dextroamphetamine and methylphenidate), two alpha agonists (clonidine and guanfacine), a tricyclic (desipramine), and atomoxetine (Strattera).
The only medication studied that appeared to increase the frequency of tics was dextroamphetamine, with increasing severity accompanying higher doses. Methylphenidate did not appear to have any consistent effect on tics.
The alpha-2 agonists both significantly reduced tic severity but caused some sedation, which diminished over time. (Patients taking these medications should be observed carefully when they stop them as rebound increase in blood pressure is common.)
Desipramine and atomoxetine were less effective at reducing tics and caused more side effects. Despramine in one study led to a significant increase in diastolic blood pressure and pulse while atomoxetine was found to be more likely to cause nausea and decreased appetite.
The effect sizes of the various medication on ADHD varied as follows: (“Effect size” is a measure of how strong an action a medication has on a group of subjects. An effect size of 0 means there is no effect while one of 1.0 means there is a very strong effect.)
0 = no effect, 1.00 = maximal effect:
dextroamphetamine: effect not studied
desipramine: 0.80
methylphenidate: 0.73
alpha-2 agonists: 0.61
atomoxetine 0.51
Surprisingly, the effect of desipramine on ADHD in these studies was reported as being greater than that of methylphendiate, which is one of the most highly regarded medication used to treat the disorder. Differences in rating scales, trial design, and in the number and type of subjects used in different studies included in this review may account for this and perhaps other findings of the study. It would be much more reassuring if science could give us more reliable and consistent results, but we have do make do with the studies that have been done rather than the ones we wish were done.
In young people with ADHD, tics usually begin 2 to 3 years after the onset of the ADD. Whether they are more frequent among those taking ADHD medications than among those not taking them is not known. Michael Block at the Yale Child Study Center has said “Most (clinicians) who are treating kids with Tourette’s syndrome and AHDH would say that stimulants are a worthwhile intervention for kids, especially if other treatments (for the tics) don’t work.”
