Sceletium tortuosum is a plant from South Africa purported to have mood enhancing and psychoactive properties. Little human research has been published with sceletium. See this link for natural ways to improve depression.

Plants of the genus Sceletium (Mesembryanthemaceae) have been used as natural medicine for the relief of thirst and hunger, to fight fatigue, and for social and spiritual purposes by San hunter-gatherers for millennia before the earliest written reports of the uses of these plants by European explorers and settlers. Wild resources of Sceletium have also been diminished by over-harvesting, poor veld-management, and possibly also by plant diseases.

The use by the Khoisan of South Africa of Sceletium plants in psychoactive preparations has often been alluded to in the literature. However, much of it is fragmentary and contradictory. Apart from chewing the dried product, after "fermentation', there are reports of uses as tinctures for sedation and analgesia, chewing the material directly and smoking the residue after chewing. The symbolic connections of Sceletium with eland antelopes, the "trance animals' par excellence of the San hunter-gatherers is noted. There is no evidence to support the view that "kougoed' or Sceletium alkaloids are hallucinogenic. The alkaloid distribution in Sceletium and other members of the family Mesembryanthemaceae are considered. Chemical studies have indicated as many as nine alkaloids in Sceletium which fall into three distinct structural categories. Mesembrine, the alkaloid first isolated and named is not the dominant constituent of plants and is weakly narcotic. Evidence is assembled to suggest that traditional and contemporary methods of preparation serve to reduce levels of potentially harmful oxalates, which are found in Sceletium and other Mesembryanthemaceae.

Use for depression
Sceletium plant species that contain alkaloids are claimed to have mood elevation and anti-anxiety properties, especially after the plant material has been fermented. The fermented preparation is locally known as "kougoed" or "channa" and has been emphasized and advertised for its increased potency when incorporated in commercial products.

Sceletium herb questions
Q. Do you have any experience of the herb sutherlandia sometimes referred to as 'African ginseng'? I started taking one 300mg tablet last week and I must say it has a very pleasant and relaxing effect. I note that I get a very good sleep with it. It reputedly has high levels of Gaba in it. There is another South African herb called sceletium which I have not tried but maybe you have. I would certainly value your opinion.
   A. I personally have not tried these African herbs but they sound interesting.

I am 42 years old and have battled with high levels of anxiety and bulimia for many years. I was advised by a psychiatrist to take 100mg of sceletium capsule a day for a few months. I have found the effects really unbelievable. I had energy, felt more balanced and my appetite decreased so that I ate ‘normally’. It doesn’t give one that spaced-out feeling, or wired to the ceiling feeling that some prescription drugs do, and it works immediately. Also my sleeping patterns were totally unaffected even though I had more energy. I have taken it for the past five months, but sadly now I have stopped because there doesn’t seem to be any research on the long-term effects. I have read that some long-term herbal medications can be the catalysts for auto-immune diseases and I am scared of doing harm. Can you give me any advice? I would love to hear that there are no long-term side effects, and I doubt that that is known.
    Unfortunately hardly any human studies have been published with this herbal product, therefore long term benefits and dangers are not fully understood. Some people prefer to alternate different mood lifters so as not to be exposed to the same one all the time.