Is it obligatory to treat OCD with the strongest psychiatric medication due to its impact on worship and faith, or is it permissible to start by trying herbs and Quranic healing before resorting to psychiatric medications?

Treatment is recommended, not obligatory. The best cure for obsessive thoughts is self-struggle, strengthening one's will, and disregarding them. There is no impediment to combining Quranic remedies, herbs, and organic treatments, provided a trusted doctor is consulted for the organic treatments. Treatment with the Quran is good, and it contains blessings and benefits.