Having faith and complete trust in Allah
We must have faith and complete trust in Allah and Allah's plan. Whenever we face a calamity, disaster, a stress ful event, an adversity or a tricky or difficult situation and conditions we should keep faith in Allah that he will cure us and bring us out of these tough situations. When the Holy Prophet Muhammad was depressed that no Quranic revelation was revealed to him for a long time and even the traitors or munafiqin started taunting him that no Quranic revelation has come for a long time from Allah then the surah's Ad duha and Surah Alam Nashrah was revealed to our Holy Prophet Muhammad (Peace Be Upon Him). In Surah Alam Nashrah or Surah Inshirah it is revealed that after every hardship comes ease. Similarly Surah Ad Duha has similar content in it as Surah Alam Nashrah or Surah Inshirah. Therefore the cure for depression or any mental problem is to recite Surah Ad Duha and Surah Alam Nashrah regularly. In the end what I would like to say is that there is cure and solution...