We know that opium use was rampant in British-India. We know that MGA used opium for the majority of his life. However, this reference proves that MGA’s teachers were even on opium.
“The truth is that the Promised Messiah himself did not claim that he learnt the manifest sciences from anyone. He (Mirza) used to say that his teacher was an opium addict who smoked Huqqa as well. Sometimes, on account of intoxication, he used to spill the contents of the bottles on the ground. What could one expect from such teachers?”…
(Al-Fadl, February 5, 1929; by Mirza Mahmood Ahmad Qadiani)