As someone suffering from clinical depression I wanted to elaborate on some of these:
depressed moodA warning sign from a Reader's Digest article that clued me in on my condition was that a person can see something that needs to be done--and that's as far as it goes. All their energy has gone into recognizing it. The same article also said to be alert if he stops shaving--but didn't say why. They no longer care enough about themselves to maintain personal hygiene? I don't know but it makes sense. And someone suddenly becoming very quiet and withdrawn *may* be a warning sign.
decrease in sexual drive This can have other causes besides depression. Decreased hormone levels for one. No romance in the relationship, or when foreplay and when/where sex happens is as predictable as a computer booting up. Fatigue from a job or "positive stress" (a promotion can do it as much as a demotion) or parenting. Or the internal struggle to accept an "unacceptable" sexuality. Certain meds (ironically, those for depression as well as for cardiac disease, for example). An impending layoff. The knowledge of a terminal illness.
fatigue or loss of energy Goes along with depressed mood.
feelings of worthlessness, self-reproach or guilt This I can identify with. I spent years getting a college degree. In the second half, my youngest daughter wanted to play with me in the yard, and I had to keep turning her down because of homework. Finally she quit asking. I got the degree, but it's obvious how much the f@$%#ing thing's worth to me. I work in a meat processing plant on the floor (Production), not in the office. If you've heard Harry Chapin's "Cat's in the Cradle" you know how I feel.
- diminished ability to think or concentrate, slowed thinking or indecisiveness
Some meds are known for this too though. Also diabetes--early sign of low blood sugar.
thoughts of death, suicide, or wishes to be dead And these thoughts are not always verbalized! IOW, just because they aren't saying it doesn't mean they aren't thinking about it.
Another one: the sad person suddenly seems very happy. It doesn't mean the crisis has passed. Many times it could signal they've made their decisions about how and when, figuring "Soon my problems will be over" and are waiting for an opportunity.
I can't say being an xjw did it (though it hasn't helped). Goes back to an abusive stepfather imo.