1. The decision on the choice of pharmacotherapy should be made individually for a specific patient, because the same drugs may not work in the same way on different patients. Treatment of anxiety disorders should be based on the use of psychotherapy or psychotherapy combined with pharmacotherapy.

In the case of using antidepressants, their effects may be visible only after a few weeks of use. At the beginning of therapy, side effects are often observed, which usually disappear during treatment.

However, it is impossible for me to clearly indicate which of the drugs will work for you in the most desirable way. Any side effects occurring while taking this type of medication should be reported to the doctor, who on this basis, after consulting the patient, will make decisions about further therapy.

You can read more about anti-anxiety medications here:
https://www.gdziepolek.pl/kategorie/zaburzenia-lekowe-nerwica

2. If your sertraline preparations and mianserin or mirtazapine are prescribed by the same doctor, you should follow the instructions for taking them. These medicines can be used together if there is a clear indication to do so. However, when used together, the effects of mianserin (or mirtazapine) may be increased and associated side effects may occur (e.g. excessive sleepiness and fatigue, headache and dizziness, nausea, diarrhoea, dry mouth, vomiting, muscle and joint pain, confusion). There is also a risk of a rare but serious disorder such as serotonergic syndrome.

If the medications were prescribed by different specialists who did not know about the other medications you use, it may be necessary to consult them in order to correct their dosage.