I'd go with rowan's idea, you are going to teach and you will probably be asked to mentor at some time. Placements are scrutinised these days by the universities who send students to you - standards for placements and teaching/supervision/ mentorship have to be high. How about speaking about the differences that the students will find in the mental health setting, to an adult clinical setting? depending on the unit, issues of security, patients wandering, etc.?
Will these students be pre- or post-reg, or both (could make a difference)?
Not quite the same but tinks, have you ever seen or heard Barbara Pointon speak about dementia/Alzheimer's? She came to our nursing conference last year and is speaking at our HCA conference in September - so moving, so inspirational. Her presentation's here (it's on the web) - but be prepared that the audience were very much affected by what she had to say, we learned such a lot.
http://www.lwdp.org.u...lful_care_matters.pdf