I have to say that it improved my life by huge amounts. It's probably a mix of the testosterone increase, confidence, discipline and also proper nutrition.
I had no self-pride or self-love and very low self-steem. Traumas in my youth and teenager ages plus a dominant mother made me a weakling with women. You know the kind, women are a special kind of person, they never do mistakes, bow to their commands, etc.
Also, from where I come, "alpha males" are ridiculed because they are like a reminescent of past times, when the macho opressed women mercilessly and all that (feminexaggeration), so the standard behaviour was women dominating, taking poor care of their own bodies ("I'm happy like that, you have no right to tell me how I should look") and making fun of any kind of manly behaviour.
Since I grew up with these things, you take them as granted, like if it was the normal thing.
But then I moved to a different country and one friend insisted on lifting, not for my body, but for my mind. "Squats squats squats, you must do it!".
I finally conceded and the improvement started quite fast. It's like if I was waking up from a very long slumber.
Now I recommend anyone (man or woman) with depression or steem issues to lift heavy and eat properly. If your body doesn't improve, at least your mind will.
TL,DR version :
So, I got to say that lifting allowed me to see things from a different angle and gave me the confidence and pride to make changes in my life that allowed me to be happy.