Here's a study showing curcumin changes serotonin and dopamine levels, and can affect OCD - positively, or apparently (if you don't have rat neurology ;-)), also negatively:
N Am J Med Sci. 2010 Feb;2(2):81-6. doi: 10.4297/najms.2010.281.
Effect of curcumin on quinpirole induced compulsive checking: An approach to determine the predictive and construct validity of the model.
Chimakurthy J,
Murthy TE.
Source
Department of Pharmacology, Bapatla College of Pharmacy, Bapatla, Andhra Pradesh, India - 522101.
Abstract
BACKGROUND:
Disorders of anxiety vary in severity to a wide extent, and obsessive-compulsive disorder (OCD) persists as the fourth most common form of mental illness and is reported to be associated with memory impairment, necessitating effective means of treatment.
AIM:
To study the effect of curcumin on OCD.
METHODS:
The present study includes the determination of effect of curcumin at 5 and 10 mg/kg in quinpirole (0.5 mg/kg) -induced model of OCD, memory retention and brain monoamine levels in rats.
RESULTS:
A significant improvement from the obsessive-compulsive symptoms induced by quinpirole was observed in curcumintreated rats; curcumin showed a protective effect on memory task. An increase in serotonin levels and a decrease in the dopamine levels were observed in curcumin treated rats.
CONCLUSION:
Curcumin treatment had shown a protective effect in OCD with considerable influence on brain monoamine levels, thus providing an evidence for the predictive and construct validity of the model.
http://www.ncbi.nlm.nih.gov/pubmed/?term=curcumin ocd