I am an 83-year-old male and had a mastectomy and proton radiation in the spring of 2021. Started Tamoxifen in June 2021. At first, I lost all interest in normally interesting activities. I also began having almost daily headaches that I suspected were at least partly caused by stress (e.g., would my cancer return with my CHEK2 gene haunting me). I had a major loss of libido and didn't care about much of anything. However, I was NOT depressed. No tearful episodes or sadness or any of the classical symptoms. Then, after a year, I decided to simplify my life by not having to finish every task on time or striving for immediate closure, etc. My headaches markedly decreased, and my libido returned over time. I am now once again very physically active but avoid the pressure of the demands of closure. Mylan brand tamoxifen prevents hot flashes, etc. Switch brands to experiment. I am glad that I didn't take an antidepressant. Google cognitive behavioral therapy and use those techniques. It helped me self-analyze. Bless you and good luck.