Is enough to take zoloft (sertraline) 50mg a day for depression and general anxiety disorders?

Sometimes: For depression 50mg is enough, for anxiety usually you need over 125mg (in adult size patients who have normal drug metabolism.).

SURE: Certainly. Start with 50mg and let it take effect over a month or so, then in follow-up with your prescribing dr. If you do not feel it is working well, the two of you can make a decision to increase the medication to the next higher dose and titrate up to the desired effect. Best wishes.