I've found that if you are somewhat depressed and still able to function, or a lot depressed and forcing yourself to function, then one of the manifestations of trying to get things done is pain.
When we say depression hurts, this is not some existential, woe is me, hurt. It's real pain that occurs when we are making ourselves, forcing ourselves to do things. And it's pain that is, well, painful.
For me it's an ongoing bad headache that just doesn't stop. And the more that I try to do, the worse the headache gets. It can be bad enough that I think that I'd rather do nothing rather than deal with this level of headache.
Today I'm taking a page out of my parent's handbook and I'm taking Panadol to see if it will work against this type of headache. We'll see. I'll let you know later today.
Update 1:
Took two 500 mg tablets Panadol (1,000 mg acetaminophen) at 9:40 am on 29 Sep 18. The pain did mostly go away within one hour, although many of the other symptoms (focus and coordination problems) remained and did not go away. I was still Depressed, but not having the pain made getting things done easier and so the rest of the day went better. At 6:00 pm, I'm still able to function pretty well.
One day's worth of experimentation with Panadol isn't enough to make claims of any kind and in fact, I really have no proof that the Panadol even helped. Still, the correlation between taking a painkiller and being able to function better is suggestive (and this is from someone who is extremely skeptical about correlations).
Update 2:
At around 5:00 pm on 1 Oct 18, took my regular daily meds which help with general stability, but by then I was already exhibiting Depression symptoms. At 6:00 to 6:30 pm, it felt hard / painful to focus on what to do next. At 6:30 pm, I took two 500 mg tablets Panadol (1,000 mg acetaminophen). The pain did mostly go away in less than one hour and by 7:30 pm my ability to focus had already returned.
Again, there are too many medications and variables involved. Still, Panadol / acetaminophen is relatively safe as drugs go. I'm therefore still willing to suggest that if you're Depressed and you're experiencing pain of any kind, even the type that feels like it's just in your head, consider taking a painkiller to see if it will help you cope with Depression.
Remember to use the drugs as directed and remember to check first to make sure they don't interact badly with any other drugs you might be taking or other health conditions you may have. And more is not better.