I actually got a depression a few years back and anxiety came with it. Part of the reason was actually procrastination/laziness. Basically I liked working nights so I was working nights all the time. The nice thing with night shifts is that you always go on 12h shifts, there are no 8h night shifts. So automatically it means you get more time off. A typical schedule was 4 days on, 4 days off, with a couple 8h day shifts mixed in, and some 12h days. Now the issue is being in night shift mode all the time made me kinda groggy. Sleep in a lot, don't feel like doing anything when I get up, go to bed late. Repeat cycle, even on days off. Very hard to go to bed early and get up early since I'm naturally a night owl. Trying to do it after night shifts is even harder.
Long story short I fell into this perpetual cycle of basically going to work, and then being off for several days and being home just doing nothing. I have lot of projects and hobbies I WANT to do but never felt like doing. It caught up with me and I started to feel depressed. Lack of natural light also didn't help. I mean, even if I'm on full day shifts I don't get light either because I'm at work, but at least on my days off I get up early enough to at least catch the tail end of the day. (days here are very short most of the year) I would get SOME light. So really the slight depression made me lazy and the laziness made me more depressed, and anxiety tends to come with depression. It can be a vicious cycle and hard to get out of. You just spiral down into darkness and next thing you know you're standing in front of a telecom battery bank and eyeing a piece of stray metal bar on the floor and thinking you can end it all right now and won't feel a thing. I didn't actually want to end it though, I knew something was wrong with me and I just wanted it to go away. But it's crazy the thoughts that come when you fall into depression.
I got it sorted out by going back to mostly day shifts, but also forcing myself to go out for walks more often, even in winter, so that I can at least get some level of natural vitamin D and also nature, since I usually go in the nature trail not far from my house. Being in nature can really help prevent depression. As a ginger I'm adapted to the north and my body can generate vitamin D more easily, but I still need to actually be out in the sun for a short while at very least, not inside. I also had to go on meds and did see a counselor. I'm off the meds now and feeling fine now. I actually went on them again around March. I find that time of year depressing and always have but guess it affects me more now. By then I'm just tired of winter, and there's really nothing happening or nothing to look forward to other than more winter. By April the snow is sorta melting but not really, so you end up with a period where you can barely even go for a walk since the sidewalks are a wreck of jagged ice, slush, and dog shit and nature trail is too mushy to walk in. If I could afford to just take 3 months off to go to a hot spot, it would be March, April, May. That way I skip the part of the year where it feels like spring is coming but not really and that constant up and down weather, and arrive back when summer is starting.