The American journal of psychiatry
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Recent clinical studies have demonstrated that a single subpsychotomimetic dose of ketamine, an ionotropic glutamatergic N-methyl-D-aspartate (NMDA) receptor antagonist, produces a rapid antidepressant response in patients with major depressive disorder, with effects lasting up to 2 weeks. Despite enthusiasm about this unexpected efficacy of ketamine, its widespread use as a fast-acting antidepressant in routine clinical settings is curtailed by its abuse potential as well as possible psychotomimetic effects. However, the ability of ketamine to produce a rapid and long-lasting antidepressant response in patients with depression provides a unique opportunity for investigation of mechanisms that mediate these clinically relevant behavioral effects. ⋯ The authors discuss recent work linking ketamine's mechanism of action to homeostatic synaptic plasticity processes activated after suppression of NMDA-mediated glutamatergic neurotransmission. They focus on their recent work demonstrating that ketamine-mediated blockade of NMDA receptors at rest deactivates eukaryotic elongation factor 2 (eEF2) kinase, resulting in reduced eEF2 phosphorylation and desuppression of rapid dendritic protein translation, including BDNF (brain-derived neurotrophic factor), which then contributes to synaptic plasticity mechanisms that mediate longterm effects of the drug. The authors also explore possible molecular strategies to target spontaneous neurotransmitter release selectively to help uncover novel presynaptic avenues for the development of fast-acting antidepressants and possibly psychoactive compounds with effectiveness against other neuropsychiatric disorders.
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Comparative Study
Neurodevelopment of children following prenatal exposure to venlafaxine, selective serotonin reuptake inhibitors, or untreated maternal depression.
Effects on child neurodevelopment of neurotransmitter reuptake inhibitors used as antidepressants during pregnancy have not been adequately studied. The authors compared the effects of prenatal exposure to venlafaxine (serotonin-norepinephrine reuptake inhibitor), selective serotonin reuptake inhibitors (SSRIs), and maternal depression. ⋯ Factors other than antidepressant exposure during pregnancy strongly predict children's intellect and behavior. Depression during pregnancy is a significant risk factor for postpartum depression. Children of depressed mothers may be at risk of future psychopathology.