The accurate answer is a qualified one, not a simple yes or no. Hypnosis has a real research base for certain uses and a thin or mixed one for others, and it is recognized for specific applications rather than validated as a standalone cure for psychological conditions in general. The honest picture is mixed, and the value lies in knowing which parts are which.
Where the evidence is strongest, it is still framed as support. The U.S. National Center for Complementary and Integrative Health notes that a growing body of evidence suggests hypnosis may help manage some painful conditions, and that gut-directed hypnotherapy has support for irritable bowel syndrome. The 2021 American College of Gastroenterology guideline does recommend it for IBS, but rates that recommendation as conditional and based on very low-quality evidence. So even the better-studied uses come with caveats about the strength of the research.
For several psychological conditions the evidence is genuinely weaker. Studies on hypnosis for anxiety around medical and dental procedures have shown promise, but the NCCIH describes the overall evidence as not conclusive. Work on depression exists but remains limited and lower in quality. For smoking cessation, a Cochrane review of fourteen trials found insufficient evidence to show that hypnotherapy outperforms other methods, with most studies at high risk of bias. These are areas of interest, not settled science.
A recurring theme across the literature is the adjunct role. Hypnosis is most often studied and used alongside established treatment, such as cognitive behavioral therapy or medical care, rather than in place of it. Suggestion delivered in a focused, relaxed state may make a person more receptive to that other work, but the research does not support treating hypnosis as a complete treatment for a serious psychological condition on its own.
So the claim that hypnosis is scientifically validated for psychological conditions is too broad to be accurate. It is recognized by some bodies for particular uses, supported by reasonable evidence for a few, and backed by weak or mixed evidence for many more. The NCCIH is direct that it is not intended to substitute for the advice of a health care provider. Read that way, hypnosis is a tool with a defined and partial evidence base, useful in specific places and overstated whenever it is described as proven across the board.