Dear Mr. Berko: Our 13-year-old son, on the advice of our family physician, uses marijuana, and it’s been a godsend. I seldom speculate but had an $11,600 short-term gain on three marijuana stocks our broker bought and sold for us last year. Our accountant told me that I can deduct the $3,630 we spend on medical marijuana, but our neighbor, who is a CPA for one of those monster firms, tells me we can’t.