Depression affects 121 Million people worldwide. In its severe forms, it leads to 850,000 deaths each year. 
There are many kinds of medication that can be prescribed by doctors to treat this condition. St. John’s Wort, on the other hand, is an herbal remedy avialable over the counter for mood.
What is St.John’s Wort?
St. John’s Wort belongs to the plant species Hypericum perforatum, and is also known as Tipton’s weed, rosin rose, goatweed, chase-devil, or Klamath weed. There are many species worldwide and they can mostly be found in North America, Europe, Turkey, Middle East, India, China and Brazil.  Australia is the world’s top producer of the plant.
Its name was given because it blooms around June 24, the birthday of John the Baptist. “Wort” is an old English word for plant. It is used for multiple problems such as for chronic fatigue syndrome, exhaustion, migraines, and muscle pain. An oil extract from the plant can also be used for easing scrapes, bruises and other inflammations. 
How does it Work?
Scientists do not yet fully understand how St. John’s Wort works in relation to mood. Its effect is generally attributed to its content of hypericin, hyperflorin, and flavonoids which help elevate dopamine, norepinephrine, and serotonin. 
Dopamine is a stimulant that produces good mood. In elevated levels, it makes the user more focused, confident and interested in what he’s are doing. Norepinephrine is similar to dopamine and produces alertness and motivation. Serotonin on the other hand manages mood, appetite, and sleep. With low levels of Serotonin, one will become anxious, irritable, and have trouble sleeping. 
During a six week trial involving patients with mood issues, a hypericum extract of 300 mg or 600 mg was given to one group while the other group used Paroxetine in 20 mg capsules. After six weeks, it was discovered that hypericum extract is as effective as paroxetine for patients with moderate or severe mood issues.
St. John’s Wort is available in both liquid and pill form. For regular use, a dose of 300 mg taken 3 times a day with meals.  The effects of the supplement may be seen in 3-4 weeks and it is recommended that you don’t stop taking it before that.