Dr Phil Kieran: Is my teen's growth spurt to blame for his marathon sleeping? 

Oversleeping regularly can contribute to changes in mood and concentration

Dr Phil Kieran: "On average, a 15-year-old needs about nine hours of sleep per 24-hour period."

My teenage son is an Olympic sleeper. He thinks nothing of staying in bed for 14 hours during the holidays. 

I do my best to get him up and out, but he says he’s exhausted. He has no signs of illness and when he’s awake he’s in good form, but not particularly energetic.