I am being treated for ADHD and BiPolar disorder. My doctor advises me to take Omega 3 supplements. 

For about 15 years I have been following vegetarian diet. I found being so I found myself having higher level of mentality and guilt free. Actually, I don't consume any dairy products or fish either so I may have been a vegan.

But if I start to take these Omega 3 pills I can no longer consider myself to be a vegan, right? 

If these pills are a product of animal harm, can someone suggest to me how to get this particular nutrient while protecting my morality as a vegan?