Turmeric has been used in traditional medicine for centuries to treat a range of ailments. Its primary active constituent curcumin, can influence an array of biological activities. Many of these, such as its anti-inflammatory, antioxidant, neuroprotective, and monoaminergic effects are dysregulated in several neuropsychiatric disorders. In this systematic review, in vitro, animal, and human studies investigating the potential of curcumin as a treatment for neuropsychiatric disorders such as major depressive disorder, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), bipolar disorder, psychotic disorders, and autism are reviewed, and directions for future research are proposed. It is concluded that curcumin is a promising, natural agent for many of these conditions, however, further research utilising robust, clinical designs are essential. The problem associated with the poor oral bioavailability of standard curcumin also requires consideration. Currently the greatest support for the efficacy of curcumin is for the treatment of major depressive disorder.