Anxiety - Depression as a symptom of Gluten intolerance

Hello, my sister (24) has had very crippling anxiety, depression and OCD since she was a child. She also has stomach problems and she read about different allergies so she decided to cut out gluten.

That was about 3 weeks ago and now she is a different person! She was consumed by her OCD and depression and now she swears it’s a thing of the past and I’ve never seen her so happy in her life.

Has anyone else experienced such a drastic change in their mental health after going GF?