Is the picking and eating of wallpaper, stickers, etc. common in children who have CdLS?
This behavior is known as pica. I would recommend testing the child's lead level in addition to anything else, since picking and eating wallpaper, etc. can be a sign of lead toxicity.
I agree that lead testing, if it hasn't been done, is important. Pica is common in children who have a lower IQ (especially moderate-severe MR), and in a select group of other children (children who eat dirt and have low iron, etc.). It is quite treatable through behavioral protocols directed by an expert in behavior therapy. Medication does not appear to make much difference, (possibly except in individual cases where pica is mixed with anxiety, hyperactivity or mood symptoms).
Legal Disclaimer: Please take note that the CdLS Foundation's Ask the Expert service is comprised of volunteer professionals in various areas of focus. Response times may vary and a response is not guaranteed. Answers are not considered a medical, behavioral, or educational consultation. Ask the Expert is not a substitute for the care and attention your child's personal physician, psychologist, educational consultant, or social worker can deliver.