Meet the Team

Leanne Hopper, EdD, BCBA, LBA

Founder/CEO/Board Certified Behavior Analyst

Dr. Leanne Hopper, EdD, BCBA, LBA is the Founder and Clinical Director of Catalyst ABA Therapy. As a Behavior Analyst for over 21 years, she is dedicated to delivering ethical, early-intervention ABA services that create meaningful, lasting change for children with autism and their families across Southeast Missouri.

Beyond the clinic, I’m deeply devoted to my family, finding joy in traveling, paddleboarding, hiking, yoga, reading, and spending as much time outdoors as possible.

Rachel Felter, MA, BCBA, LBA

Board Certified Behavior Analyst

Rachel is a dedicated Board Certified Behavior Analyst (BCBA) with seven years of experience supporting individuals and families through evidence-based practices. She is passionate about her work and finds deep fulfillment in helping others grow and succeed.

Outside of her professional role, Rachel is a proud mom to her 6-year-old son, who inspires her daily and keeps life full of energy and joy.

Nicole Sells, MA, BCBA, LBA

Board Certified Behavior Analyst

Nicole Sells is a devoted & passionate Board Certified Behavior Analyst (BCBA), working in the clinical setting and school setting. She became a BCBA in December 2025. With experience in the ABA field across many different ages, populations, & locations across the state of Missouri since 2021. She enjoys early intervention, while working diligently to increase verbal behavior/communication, simultaneously decreasing problem behavior. Additionally, she has knowledge supporting families, caregivers, and school-staff.

Meet our Provisionally Licensed Supervisors

  • Nyssa Quatmann, MA, PLBA

    Provisionally Licensed Behavior Analyst

  • Emily Ward, MA, PLBA

    Provisionally Licensed Behavior Analyst

  • Hannah Watt, MA, PLBA

    Provisionally Licensed Behavior Analyst

  • Kayla Clark, BS, PLABA

    Provisionally Licensed Assistant Behavior Analyst

See All Bios

Our RBTs

Behind everything we do is a team of people who truly care. We bring our full selves to the table—open-minded, collaborative, and ready to make something great.