It's very important to try to get out of the negative mindset when interviewing for a new job. Think of a professional non emotional way to describe your current situation. Weighing an interview down with negative comments about your old job is not a good step, so just do your best to get out of the negative mindset. Even if that is not your intention you will find they'll ask why you'er leaving and you may find it difficult to not spend the whole interview bitching about the people in your old job.

Of course it doesn't stop the fact that you are in an absolutely awful and frustrating situation. Just try and get a positive spin out of it... somehow!