Lastly,my last reason is stress, stress can come from a lot of things like work,school,friends,parents,children as you see stress comes from a lot and school stress is a big oe because we all know sometimes our grades go down and when we try to bring them up it gets really stressful and espcially if your pricipal is making you do a other activity that'll make even more stress and multiple studies have shown that a lot of the stress that kids get is from school and other activies.