I (GlyT-1) with sarcosine, bitopertin (RG1678), or ALX-5407.9–12 Sarcosine (N-methylglycine) has been used in several small studies and the results seem to be promising in ameliorating cognitive and negative symptoms where efficacy of using known antipsychotics is rather limited.13,14 Previously published studies also indicate positive changes in affective symptomatology during the use of NMDA coagonists or sarcosine,15–20 but interestingly, NMDA receptor antagonists such as ketamine and memantine also have antidepressive effects.21–23
