The BBC reports: Babies who cry excessively and have problems feeding and sleeping have a greater risk of serious behavioural problems later in life, say scientists.
One in five babies has symptoms that could lead to conditions such as ADHD, according to research published in Archives of Disease in Childhood.
The review of previous studies looked at nearly 17,000 children.
A child-health expert said it would be wrong for parents to be "overly alarmed" by the results.
Crying in babies is normal, but some cry "excessively" after the age of three months for reasons other than colic.