I have read that Scotlands greatest poet Robert Burns was a sufferer from depression.
In his most famous poem "To a mouse" this is hinted at. He finishes his address to the mouses' misfortunes with the words....


      "But thou art blessed compared wi' me,
       the present only,toucheth thee.
       While I, weary, backwards, cast ma' ee,
       on prospects drear.
       And forward,tho' a canna see.
       I guess and fear."