A mother who comes, with only a stick, to the rescue of her child being attacked by a mountain-lion may be willing to believe she’ll drive the animal away even if objectively the odds are not in her favor. She draws her strength from her biased belief. So, depending on circumstances and what is at stakes, biased beliefs can play a positive role.
People with OCD who believe they can save a relative by performing a ritual or reach indubitable certainty through endless questioning also harbor biased beliefs, but this is different. The mother rightly believes her only hope to save her child is to drive the mountain-lion away with whatever available weapon and the strength of her determination, whereas people with OCD wrongly believe at times that there is no other hope to regain peace of mind, except by giving in to compulsions. That belief is not substantiated because 75% of people with OCD are significantly helped by Cognitive Behavioural Therapy, for instance, according to OCD-UK. Stepping back and looking at all our options in a given situation helps us determine when and when not to let biased beliefs take over our judgment.
Fear of Repressed Memories
OCD is ruining my life 
Was it touched? How can I get past it?
Does OCD tell you you have to do certain things?
