Using Various Research Methods to Study a Behavior Problem Like ADHD



Attention Deficit/Hyperactivity Disorder (ADHD)

      Diagnosed when a child shows

  6 or more symptoms of inattention

  6 or more symptoms of hyperactivity and/or impulsivity

  These symptoms must have been present at an early age, persist for at least 6 months & must be associated with significant impairment in social, academic or occupational functioning.

This may seem like a strange way of defining or describing a disorder, but it is based on a diagnostic guide used by psychologists and psychiatrists and related professionals: the Diagnostic and Statistical Manual of Mental Disorders IV (or DSM IV for short) which lays out the accepted criteria for diagnosing a particular disorder.  For a little more detail on the criteria for ADHD you can look at this link:

Attention-Deficit/Hyperactivity Disorder Criteria  see syllabus for more ADHD links


  Do you know someone with ADHD? If so, you have some experience with an individual “case” on whom one might do an intensive study or “case study”. Our text also discusses Dusty, another case of ADHD. Of course anything observed in a single case may not necessarily be typical of all individuals with ADHD; we must collect data on a larger number of individuals.


Naturalistic Observations in the Classroom

      Using this method researchers have noted that, compared to the average kid, those with ADHD have trouble:

  staying in their seats or sitting still,

  paying attention, following instructions

  completing work, staying on task

  controlling impulses, controlling temper

       This method makes use of real-life situations, but it is important to use well-trained, unbiased observers.


Survey MethodResults Reveal:

      5x more males than females

      3-5% of USA school kids are taking medication for ADHD

      50-60% show defiant behavior & higher risk of conduct problems as teens

      30-60% still have symptoms as adults

      40% have a parent with symptoms

Such statistics are only meaningful if the researchers used a carefully prepared survey instrument (questionnaire or interview) and received responses from an adequate number of respondees, such that the final sample was representative of all those with ADHD.



Correlational Research: Twin Studies Look at Correlations

Is Hyperactivity Correlated in Twins?

      Male fraternal twins (not genetically identical) show almost no correlation (+.05) in their level of activity

      But male identical twins (genetically identical) show a strong positive correlation (+.71) in their level of activity (you can do a pretty good job of predicting the activity of one twin from knowing the activity of the other)

      Supports the hypothesis that genetics play a role in ADHD but does not prove a cause-effect relationship. (correlations do not prove causation)




The experimental method must be used to test the hypothesis that a particular drug treatment or behavioral treatment effectively decreases particular ADHD symptoms, or for testing the hypothesis that some factor worsens ADHD symptoms.


For example:


Hypothesis: The artificial sweetner aspartame causes increased activity, irritability, and inattention in kids with ADHD


Kids with ADHD randomly assigned to 2 groups

Manipulation of the Independent Variable:

Under double blind conditions, children in one group (the” experimental group”) received a capsule containing a high dose of aspartame, while the children in the second group (the “control group”) received identical looking capsules containing a placebo (a substance with no effects).


Measurement of the Dependent Variables:

Levels of activity, irritability and inattention of the kids were monitored and rated by parents and teachers


Results: The kids receiving aspartame were NOT more active, irritable or inattentive than the kids receiving placebo. The hypothesis was NOT supported.