I've been on zoloft (sertraline) for 6 months and lamotrigine for 2 - i am constantly fatigued - is this a normal side effect? can i expect this to pass?

No: Even though this is not a normal side effect, i am worried about you and wonder first about your health. Have you had a physical recently? Do you exercise and eat healthy food? Have you thought about meditation as it can greatly relax you. Let me know how you are doing best wishes.

Probably, depends...: Fatigue could be a symptom of many medical conditions including mood disorder for which i suppose the medications were prescribed. If the fatigue started as a side effect of the medications, changing the dosing time may help assuming there are no other medical issues like anemia et.C going on. A simple blood test may help in the latter case. Good luck.