Which quranic verses are preferred for treating mental illnesses and how many times they have to be recited?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Ruqyah is a vast topic. When the Ruqyah is performed using verses from the Book of Allah (the Quran), the Sunnah of the Prophet or words the meaning of which is understood, then it is good and its use is permissible.

The Prophet said: “Ruqyah is permissible as long as it does not involve any Shirk.” [Muslim]

Al-Faatihah (Chapter 1 of the Quran) is the best for Ruqyah from all kinds of diseases, whether it is mental diseases or something else. Also Chapters 112 and 113, as they are the best to seek refuge in Allah with, as authentically confirmed from the Prophet .

There is also a great benefit when using the confirmed supplications that were said the Prophet . For example, the patient can put his hand on the place of ailment from his body and say: Bismi Allah (in the Name of Allah) three times, and then say: a’oothu bi’izzatillaahi wa qudratihi min sharri ma ajidu wa uhaathir (I seek refuge in the Might and Power of Allah from the evil of what I feel and what I fear), seven times.

Also, the person who visits the sick should say (to him): “I ask Allah, the Great, the Lord of the mighty Throne, to cure you”, seven times, and so forth.

The entire Quran is a cure. Allah Says (what means): {And We send down of the Qur'an that which is healing and mercy for the believers.} [Quran 17:82]

If anyone recites the Quran with the intention of becoming cured by its virtue, in any manner and repeating any number of times, then it is hoped that its purpose will be fulfilled (i.e., one will be cured).

For more benefit, please refer to Fataawa 13188, 13249, 349963, 13449, 22920, 93483, and 15445.

Allah knows best.