PD 144418 is a highly affinity, potent and selective sigma 1 (σ1) receptor ligand (Ki values of 0.08 nM and 1377 nM for σ1 and σ2 respectively) . PD 144418 devoids of any significant affinity for other receptors, ion channels and enzymes. PD 144418 shows potential antipsychotic activity[1][2].