It certainly seems to have been common enough among soldiers at least, yes. I'm away from my bookshelf right now so you'll have to wait a couple hours for a specific quote, but Catherine Merridale describes this phenomenon in Ivan's War as well. Unlike Alexievich, who is citing oral reports seventy years removed from the events, Merridale is drawing on diary entries and letters home from the front as well. Many of these letters are men writing to their wives, and they describe their premature gray hairs or baldness in the context of anxiety over their physical transformations in general. They describe weight loss, scars, lost digits (either from combat or frostbite), and other permanent or temporary physical maladies of the front, as well as their deep-seated fears that their wives would no longer want them as husbands because of these injuries. Incidentally, they also frequently wrote about what we would now consider psychological injuries such as stress- and trauma-related impotence and nightmares. I believe Brandon Schechter also discusses this briefly in the section on letters and diaries in his dissertation, Government Issue: Material Culture in the Red Army 1941-1945. Given the testimony in the primary sources we have from individual soldiers, and the general level of stress & sickness they depict on top of specific references to premature grey hairs, I think we can conclude that it was reasonably frequent in soldiers, if not the populace at large.