Answer:
(If you want, you can paraphrase this.)
Being mentally healthy is extremely important to an individual and others around them. Firstly, mental health also affects other areas of health. Say if a person had depression, they may want to stop eating, affecting their physical health. Or, if a person stopped putting effort into schoolwork due to poor mental health, that would also affect their intellectual health. It can also affect those around the individual. If a teenager started to withdrawal from their parents due to poor mental health, it may worry the parents and affect their mental health as well. In conclusion, being mentally healthy is exceedingly important to oneself.