Throughout his life, the painter Caspar David Friedrich (1774-1840) struggled with depression, but he managed to remain productive by projecting his emotions into his paintings. Friedrich used oblique views, low light, cloud cover, and silhouettes to emphasize distance, strangeness, and scale. His paintings were emotionally evocative without being symbolic. Viewers sensed loneliness, longing, transcendence, love, death, regret, and the anxiety of the unknown in his paintings, without always being able to put their finger on precisely what they felt about them or how the images made them feel that way.
Cole TB. Monk by the Sea. JAMA. 2011;305(3):227. doi:10.1001/jama.2010.1986