Our C/L service is divided in two. One component is the "Behavioral Intervention Team" - they do consults on the medical floors, often initiating consults themeselves for high risk patients, and do a lot of work around health behavior, people who are non-adherent to medical recommendations, etc. This service is partially paid for by other departments and the hospital as they were able to demonstrate the capacity to reduce length of stay and readmission rates. This part of the C/L service is basically run by NP's who are very well suited to this type of work and do a great job.
The other component of the consult service does everything else, sees patients with suspected PNES, does most of the derlirium consults, takes the consults from oncology, transplant, HIV, post-cardiac etc. This service does not have NP's and is driven by the CL attendings, fellows and residents.
I think it's a great example of a rational way to divide up roles between NP's and psychiatrists that appears to work to everybody's satisfaction.