Does ashwagandha work for panic attacks? used daily? can it be used while taking sertraline, or during weening off sert ?

No: Ashwagandha is a common herb in ayurvedic medicine. It has a variety of uses -- much to do with adapting to stress. Some use it for anti-anxiety properties, but it does not have research supporting any prevention of panic attacks. There are no conflicts between it and sertraline -- but there could be with benzos. Talk w/your doc. http://www.ncbi.nlm.nih.gov/pubmed/10956379?dopt=abstract.