depression

of the central nervous system
https://doi.org/10.1351/goldbook.11711
  1. Reduction in the activity of the central nervous system.
  2. Mental state or disorder characterized by feelings of sadness and despair.
Source:
PAC, 2015, 87, 841. (IUPAC Glossary of terms used in neurotoxicology (IUPAC Recommendations 2015)) on page 861 [Terms] [Paper]