Focusing on what you're grateful for is one of the more powerful and best proven methods to combat depression. I've been through clinical depression and consider it the key to my recovery.
https://news.osu.edu/gratitude-interventions-dont-help-with-...
For example, here are the first couple pages of results I got for gratitude studies. Every single one found a positive affect.
https://journals.sagepub.com/doi/abs/10.1177/135910531557245...
https://www.tandfonline.com/doi/abs/10.1080/0144341090349393...
https://link.springer.com/article/10.1007/s10902-014-9542-3
https://www.cambridge.org/core/journals/spanish-journal-of-p...
https://www.sciencedirect.com/science/article/abs/pii/S00926...
https://synapse.koreamed.org/search.php?where=aview&id=10.12...
https://www.sciencedirect.com/science/article/abs/pii/S01918...
https://www.tandfonline.com/doi/abs/10.1080/15298868.2015.10...
if you don't care about anything, meaning you have no gratitude, how do you jumpstart this process?
When we're depressed we have a tendency to fall into the mindset that everything is bad. Reminding yourself that there is something good in your life helps break that cycle. If you can make it a habit your brain actually gets better at finding the positives and it starts to create a positive feedback loop.
P.S. If you want to learn how to make habits easier I highly recommend Atomic Habits https://www.goodreads.com/book/show/40121378-atomic-habits?f...
1. Without wondering if you sincerely mean it, make a point to say "thank you." Typically if you are depressed you will be alone, and so it is possible to recognize situations where you took an action now to make something easier for yourself later: for example, doing the dishes now instead of waiting for them to pile up. When that happens, verbally thank yourself on behalf of your future self. If you're capable of doing this, it jump-starts gratitude after a while.
2. Instead of feeling gratitude for things you perceive as positive, look for things that you perceive as neutral. The majority of your sensory experience is neutral. If your emotions are very negative, instead of looking for a dichotomy between negative and positive, look for a dichotomy between negative and neutral. You will perceive that neutral is not-negative. Because neutral is not-negative, increased perception of neutral sensations is a positive. If you perceive neutral sensations as positive for long enough, it jump-starts gratitude after a while.
In fact, I find it difficult to think that people are okay with neutral because how is that any better? You arguably still failed at whatever you were trying to do, just the results weren't as harsh. I dont know. I think I might just be really far gone at this point.
The majority of your sensory experience is neutral perceptions like that. Once you notice them, negativity seems small in terms of proportion of sensory experience. What actually happens is that negativity occupies the majority of attention, meaning that your mind is latching onto things you perceive as negative. Broadening the scope of awareness to include neutrality means that definitionally the mind is not as latched-onto the negative, therefore negative things seem smaller, therefore they are slightly more tractable to deal with.
In other words, I no longer think I am weird for not feeling joyful or being grateful for things for which I have not yet been given the chance to ask myself if I actually am grateful for them, or if I actually personally value them at all. Being stuck in someone else's narrative, or a cultural narrative, is to me like being in a jail, because the narrative will not correspond to my feelings, because it's not mine.
I now use the Nonviolent Communication set of strategies to listen to my own feelings, and use them to learn which of my human needs are unmet.
I also had Compassion Focused Therapy, which brought me back from the dead.
The writing of Francis Weller has inspired me beyond belief. If you're interested, this is a taster: https://www.thesunmagazine.org/issues/478/the-geography-of-s...
Or if you prefer listening, I love this podcast with him: http://charleseisenstein.org/podcasts/new-and-ancient-story-...