Quinolinic Acid in Depression
Quinolinic Acid is a neurotoxic compound involved in the neuroprogression of depression. Neuroprogression is a term inclusive of the various stages of neurodegeneration including apoptosis, reduced neurogenesis, reduced plasticity (neuronal and synaptic), and increased immunoreactivity . Various dynamics are involved in the neuroprogression of depression, including disturbances in the serotonergic system, increased inflammation and cell-mediated immunity, oxidative and nitrosative stress, and neurotoxic compound production . Quinolinic Acid is one such neurotoxic compound that acts as an NMDA receptor agonist and elicits excitotoxic damage via glutamatergic activation of neurons and astrocytes .
Additional studies have also shown a negative correlation between hippocampal and amygdala volume and increased Quinolinic Acid levels in patients with bipolar disorder . Another study reported that Quinolinic Acid and IL-6 levels in the CSF are positively correlated with suicide attempts in patients with MDD. Clinical and postmortem studies with individuals who had attempted to commit suicide have shown clear increase in the levels of Quinolinic Acid in the brain .