Sufferers have trouble concentrating on any task unless they receive constant feedback, stimulation and reward.

ECONOMIST: The genetic legacy of nomadism may be an inability to settle

But he told BBC Radio Nottingham that Sunday's stunning victory has already been forgotten and they will have no trouble concentrating on the next match.

BBC: Delaney puts Trophy on backburner

Your doctor will ask about whether you've been feeling down or blue, whether you've lost interest in things you usually enjoy, whether you feel guilty or especially down on yourself, whether your sleep and appetite are disturbed, whether you feel exhausted most of the time, whether you are having trouble concentrating and whether things have gotten bad enough that you've thought some about ending your life.

CNN: Stress has taken over: How can I turn my mind off?