Ritalin use is almost twice as high among children whose parents divorce compared with those who continue to live with two biological parents, a Canadian study suggests. ...This is a classic example of the vicious (or virtuous) cycle of the mutual reinforcement of nature and nurture. Successful, socially functionable parents are the most likely to provide their children a traditional home environment (living together, home in the evenings, involved in their children's lives, etc). Children who are diagnosed with ADHD tend to be have lower IQs than the population at large. And among adults, divorce rates and intelligence trend inversely.
Previous studies suggest children who live with a single parent or a parent and step-parent were more likely to be prescribed Ritalin. ...
In two-parent families, 3.3 per cent of children were prescribed the drug, which rose to 6.1 per cent among the children whose parents had divorced.
So being raised in a strong family attenuates an endowed child's sense of anxiety about what's going on at home (a potentially major point of distraction while at school), while chaotic households accentuate the anxieties of children already at increased risk of the disorder.