I've heard that playing music at night for babies and toddlers (i.e. children under 2 years old) can cause or contribute to Attention Deficit Disorder (ADD/ADHD) when they get older.
Is there any truth to, or basis for, this claim?
When I was a child (and now with my newborn son) my family has always had the habit of playing music or having some type of background noise going during sleep time. This could be anything from the aforementioned music, to a TV on low volume in another room (but still audible from the crib), to the window air conditioner in the summer.
The reason behind this is that if the child grows accustomed to any type of background noise while sleeping, it will actually end up leading to longer and deeper sleep because the child will no longer be disturbed by the slightest creak in the floorboards. Maybe me and my son are just naturally good sleepers, but my son (who is now almost 10 months) has been sleeping for 8-10 hours every night without waking for 6 months now.
As far as the claim to this potentially leading to ADD/ADHD I find that rather hard to believe and can't find any legitimate studies to back this claim up. ADD/ADHD in itself is way too overdiagnosed as it is, and even with legitimate cases of the disorder I would imagine that there are plenty of things that are occurring (or not occurring) during the child's waking time that would have a greater impact on brain development and risk for the disorder.