For SAD AND DEPRESSION, the amino-acid 5-HTP has an uplifting and calming effect on mood, as it is a building block in the brain for serotonin. Taken orally, 5-hydroxytryptophan (5-HTP for short) easily crosses the blood-brain barrier. By increasing serotonin production, 5-HTP can significantly help to ease depression and seasonal affective disorder (SAD).

Depression and SAD have been linked to neurotransmitter imbalances in the brain, particularly of serotonin and melatonin. 5-HTP is a precursor for serotonin, a crucial neurotransmitter that elevates mood and stabilizes brain chemistry. Serotonin also regulates sleep, appetite to give a feeling of satisfaction with smaller portions of food and maintaining an optimal weight. Once in the brain, tryptophan is converted to the neurotransmitter serotonin.

Unlike serotonin, the brain’s natural wellbeing neurotransmitter, 5-HTP can easily cross the blood-brain barrier, the protective membrane that acts as a strict gatekeeper to control which substances enter the brain. This allows 5-HTP to move into the brain and be readily converted into serotonin, which plays a large role in mood, creating a feeling of well-being and relaxation.

Tryptophan is a large amino acid and competes with the body’s other amino acids to enter the brain through the blood-brain barrier. Carbohydrates trigger the release of insulin, which removes most amino acids from the blood, but not tryptophan. This clears the pathway for tryptophan to enter the brain and convert into serotonin and, ultimately, melatonin.

Our bodies naturally produce minimal amounts of 5-HTP from the essential amino acid L-tryptophan, but the conversion process is slow. Tryptophan itself cannot be made by the human body. It must be ingested from the outside, and is found only in trivial quantities in turkey, milk, pumpkin, turnip and sea vegetables. Supplementation can offer a more direct supply and efficient conversion into serotonin as 5-HTP is well absorbed from an oral dose, with about 70 percent ending up in the bloodstream.¹˒²

Research studies found that depression sufferers have tryptophan depletion. Forward-looking psychiatrists have, for years, considered that a widespread tryptophan deficiency underlies the prevalence of depression. A deficiency of tryptophan is known to aggravate depression, anxiety, and aggression as well as impeding sleep, appetite, temperature regulation, sexual behavior, pain perception; disruption of any of these can worsen depression.

Serotonin deficiency, which can be due to low tryptophan in the body and brain, is linked to depression and SAD. By increasing serotonin levels, studies show that 5-HTP can improve mood and reduce feelings of sadness. The first large clinical trial using 5-HTP for depression was conducted in the 1970s. A total of 107 patients with endogenous unipolar or bipolar depression were given daily oral dosages of 5-HTP from 50 to 300 mg. Significant improvement was observed in 69% of the patients and no significant side effects were reported. The response rate in most of these patients was quite rapid, generally less than two weeks.³

While research specifically on 5-HTP for SAD is less extensive, the mechanism of action is still relevant. Disruptions in serotonin levels and circadian rhythms, our sleep-wake cycles, are associated with SAD, and reduced sunlight exposure can naturally lower serotonin production. 5-HTP is a precursor to not only serotonin, but also to melatonin which also regulates the circadian rhythms and our responses to light and darkness. Thus, by supporting a healthy melatonin level and regulating these imbalances, 5-HTP may help improve mood and sleep patterns which can be disrupted, especially during the gloomier months.⁴

Our clinic prefers a 5-HTP formula that also includes the extra benefit of glycine, a gently calming amino acid that supports your circadian rhythm and calms the nervous system. Patients tell us that symptoms of depression, hopelessness, overwhelm, loss of motivation, and sadness are gently eased by 5-HTP. They also find that 5-HTP helps them to be well-rested, which has a significant positive impact on their mood. The relationship between mood and sleep is a two-way street. Poor sleep can exacerbate the symptoms of depression or SAD, and a depressed mood or SAD can cause poor sleep.

Recommendation: 5-Hydroxytryptophan (5-HTP) 100 to 400 mg nightly, which can be taken with a beverage or light snack, or as directed by your healthcare provider.

References