Is OCD a mental illness that can be medically treated, or a demonic possession that can be treated with the Quran? And is treatment with the Quran an innovation (bid‘ah)?

Obsessive-compulsive disorder (OCD) is treated with the Quran and Ruqyah Shariah (Islamic exorcism/healing), in addition to medical and psychological treatment. Treatment with the Quran is not an innovation; it is affirmed by the Sunnah. The Prophet, peace and blessings be upon him, guided Aisha, may Allah be pleased with her, to treat with the Book of Allah, and encouraged the recitation of the Quran and asking Allah through it. Ruqyah Shariah is also affirmed with Al-Mu'awwidhatayn (the last two chapters of the Quran) and Al-Fatihah, as some Companions performed Ruqyah on someone who was stung using Al-Fatihah. The Prophet, peace and blessings be upon him, used to seek refuge for Al-Hasan and Al-Husayn, and recite Al-Mu'awwidhatayn upon himself when he complained of an ailment.