Hello Dr Ancill, First and foremost I would like to thank you for putting time and effort in answering this and other questions! I have a question about bio markers and anti depressants. I have had depressions all my life ever since childhood. Developing louder and different tinnitus than the one i had for a few years triggered another dark episode in my life. I was presribed lexapro by a psychiatrist but I hasitate to take it due to the fact that it may cause even louder tinnitus although I know the chances are small. After a few weeks I had a follow up appoinment and we talken about the medicins i have taken in the past. Since I had not taken lexapro he suggested I take the medicin I have taken in the past: citalopram. He said that if I did not develop tinnitus in the past with citalopram it will be likely that I will react in the same way now (ten years later). He said I can be quite sure it is safe since scientist can 'predict' the way you respond to medication due to bio-markers. I also asked the farmacie if I can rely on the fact that I will react the same way to citalopram now as I did ten years ago. They said I could not and that even after a few months of withdrawel one can act differenly on the same medication. What is your opinion on this matter? Thanks in advance!