In October 2013 General Conference Jefferey R. Holland talked specifically to "those who suffer from some form of mental illness or emotional disorder". His words bring light and understanding to the scary world of mental illness. Check it out.
This talk given by President Eyring in April 2012 focuses on the trials that we face in life and how trials make us strong.
"If we have faith in Jesus Christ, the hardest as well as the easiest times in life can be a blessing."
This is an awesome mormon message highlighting the idea that "He (God) expects us to pray and trust and be believing and not give up and not panic and not retreat and not jump ship when something doesn't seem to be going just right. We stay in, we keep working we keep believing, we keep trusting."