I like your question, and it got me looking for some answers to similar questions I've been thinking about too.
I don't have the full answer; the exact disparity between specific hormones and the differences between mood regulation, but I do have a pretty good research paper that looked into this.
I'd highly recommend anyone and everyone to read it - it's free to access, and even if you only read the abstract you may hopefully take something from it.
In summary though, to answer your question, there seems to be due to (as you said) riskier decision making, but just in young men, and increased stress levels in middle aged men.
I guess the men who make it through to old age (due to socioeconomic, genetic/epigenetic reasons or just pure luck) managed to not be situated on the upper end of either of these spectrums of risk taking and physical stress response, as is most likely thanks to selection pressures. However, these high mortality-linked traits have not entirely been bred out of our populations around the world as many of these high-mortality-associated men do live long enough to pass on their genome, of which some, (roughly half, on average), will be inherited.
These physical, inheritable traits are a bit like radioactive decay: They will decline in the population over many many generations if nothing else happens, but they will never truly disappear. And the problem is that the way that society works is it does in fact exert an external force on many people, pushing them towards making risky decisions (e.g. gambling, impulse buying expensive items on a pay £0 today finance deals et cetera) and to experience much higher daily levels of stress than people can cope with day-to-day. There may even possibly be epigenetic modifications occurring in individuals that would possibly be passed down to offspring if that is the case. This, I believe, alongside the increased media attention recently on mental health, is why we are seeing much more of it these days than ever before, unfortunately.
Anyway, here's the paper: Economic Transition, Male Competition, and Sex Differences in Mortality Rates
I hope you enjoy reading it, and if you have any follow-up questions I'd be more than happy to try to answer them.