Like @@jss1988 said, I had a pretest to take before meeting with the psychologist (basic psychological stuff, self-worth, family history). Then when I met with him, he warned me about some of the issues that can arise as we start to lose weight, i.e., you'll be getting more attention, how to deal with that,, also he warned that victims of sexual abuse may struggle with certain weights if the abuse occurred when you weighed a certain amount, there may be memories that you have to deal with along the way.
He asked about my support network, warned that some WLS patients will look to replace food addiction with alcohol, answered my questions, and sent me on my way. It was pretty painless: mostly an informative meeting.