A preliminary study of tryptophan depletion on tics, obsessive-compulsive symptoms, and mood in Tourette's syndrome.
Rasmusson AM, Anderson GM, Lynch KA, McSwiggan-Hardin M, Scahill LD, Mazure CM, Goodman WK, Price LH, Cohen DJ, Leckman JF. A preliminary study of tryptophan depletion on tics, obsessive-compulsive symptoms, and mood in Tourette's syndrome. Biol Psychiatry. 1997 Jan 01; 41(1):117-21.