Hi and welcome to Healthcare Magic. Thanks for your question... Depressive disorders are caused due to certain neuro-chemical imbalances in the brain (notably, decreased levels of the neuro-chemicals - Serotonin and Nor-epinephrine) But, there is no relation between a sinus problem and such neuro-chemical imbalances. Zoloft (Sertraline) is an anti-depressant medication and Xanax (Alprazolam) is an anti-anxiety medication. Anxiety symptoms often co-exist with depression and share a similar neuro-chemical basis. I hope that you have been started on these medication after a detailed evaluation by a psychiatrist. Now, please remember that anti-depressant medication have to be taken REGULARLY for an adequate duration of time (usually, for at least of 4 - 6 months). They are NOT meant to be taken on a as needed basis. The reasons are: 1) anti-depressants take some time (at least 2 to 3 weeks) to reach adequate and steady levels in the body and bring about their effects, and hence a regular dosage is essential. 2) if they are not taken for an adequate duration or stopped prematurely, then there is high risk of relapse / recurrence of your depressive symptoms. (Even when you have completed an adequate duration of treatment, the dosage has to be gradually reduced and then stopped, rather than stopping it abruptly) 3) if you take medication irregularly, then your depression will not resolve fully and you may be later on required to take a different class of anti-depressant or a higher dosage or combination of medication. Therefore, PLEASE DO TAKE YOUR MEDICATION REGULARLY and have regular reviews with your doctor to discuss your progress / improvement. And do not stop medication abruptly or alter doages on your own. All the best. - Dr. Jonas Sundarakumar Consultant Psychiatrist