The question to ask is “Why is serotonin low?”

For example:
1. Serotonin production can be low because the body is responding to stress by increasing norepinephrine production. To do so, the body has to automatically reduce serotonin production – one of the controls for norepinephrine. Serotonin blunts one’s senses. Reducing serotonin would help improve awareness of threats from the environment.

2. There may be inadequate intake of Tryptophan, the precursor for serotonin.

There is no one best way to increase serotonin. The treatment has to be tailored to the person.

If the production of serotonin is being downregulated in response to stress, then one can force the signal upwards by using a serotonin-reuptake inhibitor (SSRI). This prolongs whatever serotonin signal one has left. This is a commonly used treatment to raise serotonin. It doesn’t increase production. It prolongs the signal.

Adding Tryptophan or 5HTP is an option under stressful conditions but it may not work very well because one’s body is actively reducing serotonin production as part of a survival mechanism in response to stress. Sometimes it works – but usually only under low stress conditions, where the person is not seriously mentally illl. By “low stress”, I would mean regular day-to-day life stresses, rather than traumatizing stress – such as actual trauma or living in poverty.

If low serotonin is because there is inadequate intake of tryptophan – such as in those individuals with high protein, low carb diets, which worsens tryptophan absorption – then adding tryptophan or 5-HTP would helps give the body the precursors for serotonin.

If there is a response to stress, then the question shifts to what are the causes of stress. Addressing the causes of stress would help restore serotonin production – without having to add more serotonin to the system.

For example, if one loses thyroid hormone or if the adrenal glands become exhausted such that the body’s capacity to generate energy is reduced, the brain automatically raises norepinephrine and reduces serotonin production. Raising norepinephrine (the primary stress signal) is another way to generate energy and is used as a compensatory mechanism for reduced energy production. Optimizing thyroid hormone and hypothalamic-pituitary-adrenal axis function would help restore serotonin signaling.