There are only THREE causes of any disease--chemical poisons, parasites and radiation. That means that you are deficient in nutrients when they can't get to the cells OR you are not eating a good diet. Poisons screw up hormones that change mental processes. Young people these days do not usually eat a good diet. Our food is poisoned, irradiated and full of chemical poisons. Birth control pills can make you depressed. Vaccinations poison. Read labels, get your food at the farmer's market, stay away from the center aisles of the grocery store. Eat grass fed, stay away from drugs. This world is not a friendly place no matter how old you are, so be happy and know that you are an important person in the world. Find out what means the most to you and pursue it.