There are several medications that can verifiably cause fear and panic. One good example here are antidepressants. But also the so-called neuroleptic drugs that are given to treat schizophrenia are now counted among the potential triggers of anxiety disorders. As indeed is the prohormone thyroxine, which is administered for an under-active thyroid gland. Most of the panic attacks, however, are triggered off much by recreational drugs like THC or ecstasy.