Vincent had them. In fact, quite often and quite intense. The causes were so different and so many that one can say he was depressed because of…well, life.
He was depressed because he couldn’t draw or paint as well as he wished. He was depressed because women didn’t like him. He was depressed, also, because he was totally dependent, financially, on his brother. Theo payed for his bread and butter, for his colors and canvases and even for his alcohol, his prostitutes and tabacco and coffee. True, he gave Theo all the drawings and paintings he produced but, then, they worth almost nothing. Excepting Anna Boch (and THEO), nobody really bought a painting of his. A lot of other reasons depressed him also: his failing health, the looming menace of the madness, the evolving syphilis (only one of the causes for his failing health; how can one be healthy when abusing his body in so many ways? Excessive drinking (of absynth and cognac and bad wine), excessive coffee drinking, excessive tabacco smocking… And lets not forget: excessive, strenuous work. A blessing but also a curse.
Eventually, all these accumulate, piles up and your bout of depression becomes a raging depression, a depression so violent that drains you down to calmness and resigned acceptation of whatever happens to you. You just don’t care any more.
I assume (wrongly maybe) that this was the mood, the state of mind of Vincent when (if) Réné Secrétan, the spoiled bourgeois brat, managed to somehow shoot him. He kind of welcomed the bullet and went with the tide. Too tired, too depressed to fight anymore.
I know, I have my bouts of depression. With a lot of his reasons to be depressed. No Theo, though. That would have been nice…