Hi there ~
I understand your concerns. The very fact that you have a history of seizures would make your usage of marijuana even more concerning. Marijuana will show up on urine and serum tox screen for about a month to 4 months since having last used the drug. On the contrary, the fact the you were using marijuana would make you more likely to have elevated risk for seizures and I strongly advise you to quit smoking
marijuana. I also advise you to be frank and upfront about your usage and let the psychiatrist
know in detail about your drug usage so as to get the appropriate treatment.
I hope this helps. Take care and have a lovely day!