In a controlled trial, 60 patients were randomized into three groups (45). One group took prozac, another group took a gram of curcumin and the third group took both prozac and curcumin.
After 6 weeks, curcumin had led to improvements that were similar to prozac. The group that took both prozac and curcumin fared best.
According to this (small) study, curcumin is as effective as an antidepressant.
Depression is also linked to reduced levels of brain-derived neurotrophic factor and a shrinking hippocampus, a brain area with a role in learning and memory.
Curcumin boosts BNDF levels, potentially reversing some of these changes (46).
Many other studies have shown beneficial effects of turmeric and curcumin.