Is paranoia considered as LDT?

The specific symptom or diagnosis is not what qualifies you (or doesn't qualify you) for LTD. What matters is if you are functionally disabled from working, as defined under your specific policy. In other words, if the paranoia prevents you from being able to work, in a way that satisfies the definition of "totally disabled" under your policy, then yes, you would be entitled to LTD benefits.