Final answer:
The specific mental health treatment for inmates in state prisons in 2000 isn't directly mentioned in the resources, but it likely included therapy and medication management, amid growing attention to inmate mental health care.
Step-by-step explanation:
The most common type of mental health treatment being received by inmates in state prisons in the year 2000 is not explicitly detailed in the provided resources. However, according to trends and practices around that period, it was likely that traditional forms of therapy, such as individual counseling, were commonly used, along with some form of medication management. It's important to note that during this time, there was increasing attention on the mental health needs of inmates, with a focus on providing more comprehensive and effective treatment programs, although the availability and quality of such treatments varied widely between facilities.