The present invention provides, inter alia, methods for enhancing the anti-depressant efficacy of a selective serotonin re-uptake inhibitor (SSRI) in a patient being treated for a mood disorder. These methods include administering to a patient in need thereof a therapeutically effective amount of an SSRI and a therapeutically effective amount of a modulator of histone expression. Also provided are methods for identifying a patient population that suffers from a mood disorder that is more likely to respond to SSRI treatment. Further provided are compositions for treating or ameliorating the effects of a mood disorder.
