How Should Conversion Disorder With Loss Of Sense Be Treated?

I have daughter of 12 years. She has been suffering from conversion disorder. At present she is being treated by anti depressant and Propranolol. But we don t see any improvement. Her attacks occurs while she is awake specially when she comes to sleep. It remains for 10 to 15 seconds and she get a hiccup and then gains her sense. Could you please give me a good suggestion?