The treatment should depend on the form of the conversion disorder, but it's rare that ideal tx will happen on an inpt psych unit. Usually neuro or medicine is better to assure it's really conversion, with psych consulting. If it's pseudoseizures, 24-hour video EEG monitoring should be the first step to make sure it's conversion. I don't think an inpt psych ward is appropriate for that. Neuro is obviously ideal, followed by outpt therapy.
For conversion d/o paralysis or weakness (motor specific), an amytal interview can be useful, which requires slow IV push, but this is also not usually possible on a psych unit, and more of a diagnostic procedure than treatment per se. Keep in mind there's case reports of patients suiciding after symptom removal via amytal.
Hypnosis is the old school treatment for symptom removal, and may help in revealing if someone is suggestible, which conversion patients usually are. Again, somewhat more diagnostic, though can be a part of longitudinal treatment.
Quality psychotherapy for sx removal isn't usually available on an inpt basis, and I don't know of any literature on using something like CBT, though theoretically it could work since they're very suggestible and laying out a stepwise course of recovery would likely lead to just such a recovery. Psychoanalysis was designed to be THE psychotherapy for treatment of conversion d/o (named hysteria at the time), but we all know the financial limitations.
And of course make sure to keep in mind factitious and malingering in the ddx.
Seems for the most part the only reason to admit a pt to the psych unit is to give respite to the family, rather than for a hope of recovery. Especially since family dynamics may play into it, admitting with hope of remission will likely lead to relapse after being released. Longer term therapy with family education is essential.
I treated a pt. with severe conversion d/o throughout my residency. I saw him first as an intern, when he was having drop attacks. Everyone thought it was seizures or narcolepsy. I hypnotized him and he could have temporary reversal of symptoms. I picked him up as an outpt case 2 years later and he had been chased with meds (interestingly had conversion sx's of psychosis as well, and had been dx'd as schizophrenia many years earlier). By the time I inherited him as an outpt he was mute, nearly completely immobile with "freezing" episodes throughout the day. Epilepsy and narcolepsy had been ruled out. I stopped changing his meds and saw him once weekly for psychotherapy for 2 years, using a combined approach of hypnosis, psychodynamic, with psychoeducation for the family. He had nearly complete symptom resolution of the motor symptoms within 9 months, and complete resolution of his pseudohallucinations within 15 months.