In experiments, rapid depletion of tryptophan in the body worsened unipolar depression in people who were already depressed. Even more impressively, people who were in remission from their depression, when deprived of tryptophan, relapsed!
Tryptophan is an amino acid that is present in protein-containing foods. It is a precursor of serotonin, which is the target molecule for the class of antidepressants known as selective seratonin reuptake inhibitors (SSRIs). They work by inhibiting the body’s method of recycling serotonin, which is secreted by brain cells as a chemical messenger. That causes the net amount of seratonin to go up, since it’s not being reabsorbed. Increasing the level of seratonin in the brain often improves depression.
My question is: since SSRIs are known to worsen bipolar depression, could tryptophan depletion improve it?