Anti-depressants can throw a bipolar person into an episode and often do not help much with the depression. I was on anti-depressants for a long time because I was diagnosed with depression long before I was diagnosed bipolar and they really only made a small dent in the depression. Now that your son is diagnosed he can work towards finding the right drug to help him stabilize his moods. This can be a long and arduous journey. Best of luck.