The Primary Project (formerly the Primary Mental Health Project, or PMHP) is a school-based early intervention and prevention program that addresses the social and emotional needs of children in kindergarten through third grade who have social or emotional school-adjustment difficulties (but not serious dysfunction). It is based on the principle that traditional school-based mental health efforts are insufficient to meet the needs of children who could benefit from additional help. Implementing Primary Project involves a reorganization of the school-based mental health delivery system to include paraprofessional "child associates" who work more intensively with students.

The program uses early screening tools with all children to identify those in need of additional supports early in their school career. Typical candidates include children who are acting out, display mild aggression, are anxious or withdrawn, or have learning problems that interfere with progress in school. The teachers, parents, and school counselors of each student collaborate to develop an intervention plan that establishes goals for the student's treatment. The core of the intervention is the creation of a strong relationship with the child associate, who meets with the student for one-on-one counseling sessions one 25- to 45-minute session a week during 20-25 weeks a year. The child associate meets with the student in a structured playroom environment in expressive play sessions intended to reinforce and build on the child's strengths. Progress is assessed during regular meetings between the child associate and school mental health professionals and midintervention progress reviews.

The goals of this program are:
- Detect school adjustment difficulties
- Prevent social and emotional problems
- Enhance learning skills

One study demonstrated that participants made significant improvements in task orientation, specifically in working more independently and completing tasks faster. In behavior control, program students showed increased coping skills and lower levels of aggressiveness and produced fewer disruptions. In assertiveness, students had improved participation in activities, were better at expressing ideas, and showed increased leadership and decreased shyness. Improvements in peer sociability included increases in the quality of peer relationships and improved social skills. Several other evaluations of the Primary Project present evidence of improved school adjustment and decreases in problem behaviors for participants.

In the Hennepin study, the comparison of pretest and posttest T-CRS results showed statistically significant changes as a result of the program in all four competence areas across the county. Program students made significant improvements in task orientation, specifically in working more independently and completing tasks faster. In behavior control, program students showed increased coping skills and lower levels of aggressiveness and produced fewer disruptions. In assertiveness, students had improved participation in activities, were better at expressing ideas, and showed increased leadership and decreased shyness. Improvements in peer sociability included increases in the quality of peer relationships and improved social skills. Jefferson County study researchers found similar improvements from pretest to posttest in all competence areas at both the State and district level.

Several other evaluations of the Primary Project present evidence of improved school adjustment and decreases in problem behaviors for treatment children. One control group study, with 600 children from 18 school sites randomly assigned into immediate intervention and delayed treatment groups, showed statistically significant decreases in adjustment problems for children receiving program services compared with children waiting for services. Another wait control group design, which employed a 3-month follow-up measure, demonstrated for the treatment group a decline in teacher ratings of learning problems and shy/anxious behaviors and an increase in task orientation and peer social skills. One of the matched comparison group evaluations showed a decrease in adjustment problems and an increase in adaptive competencies after 1 school year in favor of the treatment group. Long-term effects were found in a follow-up study of fourth through sixth graders 2 to 5 years after the intervention. Posttest-only results showed treatment children to be better adjusted than a demographically comparable group of current problem children, based on teacher identifications and ratings, in a statistically significant finding.