Rory McIlroy may be suffering with a mini form of post-traumatic stress disorder, according to psychologist Stephen Smith.

The Northern Irishman has gained an unfortunate reputation for choking in the latter rounds of major tournaments, and he has now gone 11 years without a victory.

Smith believes that those kind of memories can have an effect on performance.

He told BBC Sport: "It is possible for people to build something up in their heads and say this is the one that I struggle with because previously something bad happened.

"That memory hasn't been processed properly out of what we call the short term executive memory into your long term memory.

"And it's literally interfering with the performance message from the higher order brain. It's almost like a mini form of PTSD."