From the Holy Quran:

Mental ill health or physical ill health can affect people for many reasons not all of them can be scientifically and logically explained. 

The Holy Quran, is a book of guidance, filled with mercy and healing for all woes and ills faced by mankind:
"And We send down from the Quran that which is a healing and a mercy to those who believe..." (Quran 17:82)

Prophet Mohammad (Peace Be Upon Him) said:

"There is no disease that God Almighty has created, except that He also has created its treatment."

Therefore it is important to seek a cure only in the manner prescribed by Prophet Muhammad (Peace Be Upon Him). At the same time it is important to understand that it is permissible and at times obligatory, to seek help from medical practitioners.

In accordance with the holistic approach Islam takes to health, there is no disagreement in seeking a cure from both medical science and permissible spiritual means. It is of utmost importance to ensure that all spiritual help should be taken only from Genuine Spiritual Healers and an effort must be made to stay away from the temptation of listening to or taking advice from soothsayers.