Inexpressibly Melancholic

The desire to rid himself of depression—and the loneliness, the despair, and the fears that were part of it—was the most powerful force that motivated Vincent to become an artist and incited the intense energy that was so vital to this end. His pictures became his companions, his mistresses, and his children. "The work is an absolute necessity for me," he wrote. "I can't put it off, I don't care for anything but the work; that is to say, the pleasure in something else ceases at once, and I become melancholic when I can't go on with my work."  He observed at another time that hard work was the way to avoid "that melancholic staring into the abyss."  "I feel inexpressibly melancholic without my work to distract me, as you will understand, and I must work and work with facility. I must forget myself in my work, otherwise it will crush me."  

-  Vincent Van Gogh (Found on: Stranger on the earth; a psychological biography of Vincent van Gogh by Lubin, Albert J - Page 22. )