Yes, DEPENDANCE is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, P 3, E 1, N 1, D 2, A 1, N 1, C 3, E 1.

Is it a valid word?

DEPENDANCE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

being abnormally tolerant to and dependent on something that is psychologically or physically habit-forming (especially alcohol or narcotic drugs)
the state of relying on or being controlled by someone or something else