Can a problem with your thyroid cause confusion to the point of someone seeming to be going crazy?

Rarely: Very rarely severe hyper- or hypo-thyrodism can cause confusion, but it should be easy for your doctor to diagnose or rule out with a simple history, physical and lab tests.

Testing of thyroid function is part of the evaluation of dementia, and hypothyroidism may be a reversible cause of cognitive loss. Typically hyperthyroidism seems not to compromise memory, but may present with emotional changes. "Going crazy" would be very rare as severe thyroid issues should be readily diagnosed by most physicians, prior to a catastrophic outcome.