The answer is K.I.S.S.-keeping it simple & succinct. The socioeconomic climate in the United States & postindustrial societies is becoming more precarious in scope. The middle class is becoming the middling class as middle to high level white collar & middle to high level blue collar jobs are disappearing due to computerization. As a result of increasing computerization, many in the middle class are being downsized &/or laid off. Many middle class level jobs are being outsourced overseas to cut costs & save the corporations money. The middle class has become the middling class. Some are even becoming the new lower class. If that doesn't get people depressed, nothing will.
The socioeconomic climate has become so precarious & tenuous that many people who used to be 1-2 paychecks away from homelessness are now 1/2 to 3/4 of a paycheck away from homelessness. Now, that is alarming beyond shock. This is future shock & then some. Jobs now require an intermediate to advanced level of computer & technological knowledge. Those who aren't computer or technologically savvy will either be the new poor or the disenfranchised underclass. This new poor & disenfranchised underclass will be....PERMANENT.
It has been predicted decades ago(my late mother stated this) that in the future, there will be only TWO socioeconomic classes- the very rich & the very poor w/the middle class virtually being decimated. Those who have the smarts, talents, relevant educational levels, & the computer/technological savvy will be part of the upper socioeconomic echelons of society while those who don't have the smarts, talent, relevant educational levels, & the computer/technological savvy will be the socioeconomic poor, even impoverished. In essence, the latter will be left behind. With widening chasms in social class, there will be a corresponding correlation in the amount of depression experienced.
Besides the chasm in socioeconomic class, there is less certainty in mores & ethics. To some people, this broadening in mores & ethics in addition to the changing definition of gender & family roles creates a sense of anomie. There is a social anomie in which people really don't know where they stand gender-wise & family-wise. Postmodern cultures & societies are advancing at a furious pace & people really don't know where they specifically stand. They have lost their psychological, even psychic anchor & oftentimes depression is the result.