My understanding is as follows: if hand tremors are a side effect of an antipsychotic (yes, EPS), then Cogentin can help alleviate or remove them. If it is a side effect of another type of drug, then only going off that drug (or dosage removal) can help. I had severe hand tremor on Depakote (worse than what my grandmother had after a stroke in old age) and I had to go off of it (Depakote also produced severe weight gain and blood clotting problems, so there were several reasons why I went off of it).