Child stops to speak at all suddenly

[vbis]

My friend’s 6 year old daughter stops to speak at all at age of 2.
He tried speech therapy with the child, but no results so far.
Doctors haven't given diagnosis for the problem, and he has tried several therapies prescribed from the doctors, but the child does not speak at all.
They live in Macedonia, Europe, which is relatively small country, so I am wondering if there are similar cases with working therapy, or any diagnosis for the disorder.
I appreciate every reply on the theme
Thank you

[jdtm]

Actually, there is a very, very serious anxiety disorder similar to what is described here.  The child stops speaking - to everyone.  Psychological treatment can help but this is very difficult to treat.  It is called "Progressive Selective Mutism".  Could this be the issue?

[margypops]

Does she have other behavioral problems or is it only the Speech, does she have any Tantrums or does she seem happy , how is she at school and has she friends and Family around?.

[RockRose]

Severe psychological trauma can cause that.  Do you know of any trauma she suffered when she was two?