Mikaela Shiffrin says she is dealing with post-traumatic stress disorder following a crash in November and will not defend her gold medal in giant slalom at the Alpine skiing world championships.

Mikaela Shiffrin said she will still race the slalom and team combined at worlds but said she's "not there yet" with giant slalom.

The well-decorated racer is coping with the mental fallout of a scary crash she suffered last November in Killington, Vermont.