In addition, patients with genetic creatine disorders (Arginine-glycine amidinotransferase (AGAT), Guanidinoacetate methyltransferase (GAMT), or Solute carrier family 6 member 8 (SLC6A8) deficiency) characterized by mental dysfunction were found to benefit from supplementation with Cr soon after birth [5], pointing to a possible association of creatine function with the cognitive performance [6]. Here, SLC6A8 is linked to psychiatric disorder.