Tina's cousin should have some proper diagnostic testing before any diagnosis is made. Behavior problems and difficulty concentrating can be caused by many different factors such as parenting issues, sleeping problems, dietary concerns, learning disabilities or developmental issues. I would start with age appropriate normative based scientific testing. I would use testing that covers all areas of development including cognition, communication, social skills, sensory abilities and adaptive skills. To get a good idea of what is really going on, the test results need to be compared to a sampling of other test scores of children of the same sex and age. Based on this students apparent symptoms that are seen in the classroom, I think it is possible that Tina's cousin may be diagnosed with ADD. ADHD, or possibly an autism spectrum disorder.
