Answered by Sayyidi Habib Umar bin Hafiz (may Allah protect him and benefit us by him)
What should someone who is in a state of depression do?
They should place their hope in Allah and remember Him abundantly.
They should recite the following in abundance:
لا إِلَهَ إِلَّا أَنْتَ سُبْحَانَكَ إِنِّي كُنْتُ مِنْ الْظَّالِمِين
La ilaha illa anta subhanaka inni kuntu min az-zalimin
‘There is no deity save You, transcendent are You, truly I am amongst the wrongdoers’
They should recite Ayat al-Kursi, Surat al- Inshirah, Surat al-Ikhlas, Surat al-Falaq and Surat al-Nas after every prayer. They should also bestow abundant prayers upon the Prophet ﷺ.