Hey....I write in a journal every day and I find it helpful. I think that when we are depressed we have less control over our thoughts, which often leads us to lose track of them and fall deeper into a downward spiral. Writing in a journal can help you see your thoughts more clearly and notice how distorted they often are when you're depressed. It will help you notice what is at the root of your depression. This can motivate you to question your delusions and make changes in your life or to seek help. The first step of curing depression is knowing you have it and how it is destroying your life. You can also turn your thoughts into poetry, which is just a more fun and creative way of expressing yourself. Writing in a journal doesn't take a lot of time or effort and reflecting on your day can help you float instead of allowing yourself to sink lower and lower.
Hope you're doing well.