From The Oxford English Dictionary:
Intense enthusiasm or mania for writing.
Later frequently with reference to the use of the term by the Brontë family
. . . .
1813 C. Hutton Miser Married II. xxxvii. 191 When the scribblemania possesses any of us.
1836 C. Brontë Jrnl. Oct. in H. Glen Cambr. Compan. Brontës (2002) ii. 34 I am just going to write because I cannot help it. [Branwell] might indeed talk of scribblemania if he were to see me just now.
Link to the rest at The Oxford English Dictionary