To clarify, before anyone says anything - I don't think you're a weak person for being depressed. Period.
I know someone who is struggling with depression brought on by grief of losing a loved one a year and a half ago. They're so weak and tired that they can hardly get out of bed in the morning. There's no reason, no motivation, and simply sheer weariness at the idea of moving/going/doing. They're too tired.
(Please know dear friends, it's not as cut and dry as I'm making it, and having felt even a speckle of grief myself, I know there is a canyon more that I'm leaving unsaid.)
And as I listened to my new friend as she asked for prayer and confessed her struggles, one scripture popped into my mind: "The joy of the Lord is my strength"
I came home, and searched my Bible for the full scripture fully expecting to find it within the book of Psalms. It just sounds like a David thing to say. But that's not where I found it.
Instead I found it within the pages of Nehemiah. Nehemiah chapter 8 verse 10
Ezra reads the law to Israel and they understand how grievously they, and their forefathers have transgressed that law and the people began to weep and mourn. but Nehemiah and Ezra and the Levites teaching the law to the people said "Don't weep or mourn". Then Nehemiah says the words in verse 10: "Go your way, eat the fat, drink the sweet, and send portions to those for whom nothing is prepared; for this day is holy to our LORD. Do not sorrow, for the joy of the LORD is your strength."
I expected the verse to be in Psalms because it just sounds like something that should be in a praise song. But instead, it's surrounded by mourning, weeping, and grieved souls.
2nd Corinthians 12:10 is one of many that uses the statement of weak people being strong: Therefore I take pleasure in infirmities, in reproaches, in necessities, in persecutions, in distresses for Christ's sake: for when I am weak, then am I strong. And I like those verses in connection with the "joy of the Lord is our strength" because it's not about WE are strong. But it's about Paul being weak in body but still going about his Masters business. Because the Master provides strength for the day. Paul wasn't strong enough to survive everything he was put through - no one would be. No one in their right mind/body sings praise songs after being whipped and chained into a prison cell. But by Gods strength something different came from it than what Paul could do in his human strength.
It doesn't seem right or good to tell someone grieving that the joy of the Lord is their strength - but when you're at your weakest, when you begin to stand up in God from the moment you wake up and have to force yourself out of bed, to the moment you have to crawl into that empty bed at night, at the end of the day you'll know you got through that day because of a strength other than your own.
It's bitter/sweet words, I know. I'm sorry, so deeply sorry for the suffering she and so many others are facing right at this moment, but there is strength in joy. And I pray you all find a way to walk in that joy today, tomorrow, and the next until you can't imagine any other way.