Elon Musk insists he only takes ketamine “once in a while”.

The Tesla billionaire, 52, opened up about his use of the drug to say he restricts its use to treat depressive states – and insisted his habit should not make investors fearful about his ability to run his companies, which include X and SpaceX.

He told ‘The Don Lemon Show’: “What matters is execution. Tesla is worth about as much as the rest of the car industry combined… so that’s pretty good.

“From an investor’s standpoint, if there is something I’m taking, I should keep taking it.”

Dad-of-10 Elon added to Don, 58, he only takes ketamine “once in a while” when he is in a “negative chemical mind state” – adding he typically consumes a small dose every other week.

He declared: “It’s not a common thing.”

The SpaceX founder then raved about how the anaesthetic, which he said was prescribed to him by a doctor, is “helpful for getting one outside of a negative frame of mind”.

Elon stopped short of saying he had been diagnosed with depression, but admitted there are times when he suffers “sort of a negative chemical state” in his brain which he confessed was “like depression”.

The entrepreneur added he does not normally do drugs or drink, saying: “If you use too much ketamine you can’t really get work done and I have a lot of work.”

He went on about how his work left him with no time to go off the rails: “I’m typically putting in 16-hour days. That’s normal for me, and it’s rare for me to take off even a weekend day, so I don’t really have a situation where I can be not mentally acute for an extended period of time.

“I can’t really get wasted because I can’t get my work done.”