Our Team


Cornerstones of Maine is the result of a labour of love for our two founders, Josh and Jake.  It is independently owned by them and was established on the foundation of their desire to create a young adult transition program that is based on mental health research and experience. Not only are they the founders, they are also part of our core clinical staff.

Administrative Team

Joshua Altschule, Psy.D.

Co-Founder and Clinical Director


Josh is a licensed clinical psychologist who has spent fifteen years specializing in treating and assessing adolescents and young adults in various settings such as residential treatment programs, boarding schools, and private practice. Cornerstones of Maine is a concept that Josh has been working on for the entirety of his career. As a psychologist he has derived tremendous value from helping individuals reach their potential and overcome mental health issues that have prevented successful independent living.    


Josh has a passion for working with young adults. He also shares a similar fervor for environmental issues and organic farming. Prior to his clinical training Josh was an AmeriCorps volunteer in south Florida serving as an interpretive park ranger for the National Park Service. There he developed and implemented environmental educational camps for adolescents from the local communities and inner city areas. He also served as a researcher for U.S. Fish and Wildlife Service working with endangered sea turtles. Over the past ten years he has developed an interest in organic farming, and with his family manages their own organic gardens.

Jake Gelles, Psy.D.

Co-Founder and Administrative Director


Jake is a licensed clinical psychologist who has had extensive experience working in the mental health field as both a therapist and an administrator. As a clinician Jake has worked in both inpatient and outpatient settings with children, adolescents, and adults.  His work has been characterized by the philosophy of meeting each and every individual where they are and helping them achieve the growth they desire. This work uses the integrationist philosophy that incorporates behavior, thinking, and emotional life. His clinical experience has provided him with a strong understanding of what enables an individual to make constructive change in their life and how to activate that change towards growth and goal achievement.


Jake sees Cornerstones of Maine as a new avenue for reaching out to adolescents who need some additional help to reach their potential. Having experienced his own personal struggles as an emerging adult, he intimately understands what it takes to go from being a struggling young adult to being a highly effective and success-oriented adult. He brings those lessons to Cornerstones of Maine so he can help our residents develop the emotional maturity and confidence it takes to reach their goals. Jake also has a passion for cooking, reading, music, and philosophy that he hopes to share. 

Aaron Rumsey

Admissions Director

Aaron joined our team in March of 2020. Aaron is a psychotherapist with more than a decade of experience providing direct clinical services to young adults. He has also served as a clinical administrator, more recently at the Oliverian School, where he was the clinical director.  As a clinician Aaron's experience has bridged diverse environments including therapeutic boarding schools, wilderness programs and clinical outpatient and inpatient settings. Aaron's approach to his clinical work with young people has centered around creating warm, authentic and genuine rapport and connection through active listening. 


Aaron's current work at Cornerstones of Maine is focused on interviewing applicants and their families to ensure a good fit between candidates and our programmatic work. This is a significant shift from serving as a psychotherapist, but Aaron feels that his past clinical experience will be invaluable in helping families assess whether Cornerstones is the right program for them. 


Aaron is an active participant in outdoor activities with his children (and old "puppy," Hercules), he values the rejuvenating and balancing power that the relationship with nature can provide. 

Fred Poisson

Program Manager

Fred is a Certified Personal Coach who has helped diverse groups of people with weight loss, detox, emotional support, and goal setting. His passion is empowering people to empower themselves. Fred is a deep believer in the power of mindfulness, our personal abilities to heal our bodies and our minds, and have a deep understanding of, as well as a certification in, the power of a whole food plant based diet. He is a vegan and a distance runner and furthering his studies in herbalism and health and wellness. Fred is married to the love of his life and has two amazing children. It is his deeply held belief that if you have the power to help someone, then that is what you should do.

McKenzie Close

Administrative Manager

McKenzie was born and raised in the great state of Maine and graduated from University of Southern Maine with a Bachelor's in Psychology. She has varied experience supporting administrative teams, working on projects big and small for organizations in Southern Maine. McKenzie has a passion for helping others and in her free time she can be found reading, hiking, kayaking, boating, and spending time with her family and friends. 

Arien Lison

Marketing & Outreach Coordinator

Arien is a Maine native with a dual Bachelor's degree in Health Science and Business Marketing from the University of Southern Maine. She has more than 8 years of marketing and event production experience in the healthcare sector. She enjoys learning about photography, aerial yoga, cooking, and spending time with her family, friends, and two pups.

Jason McMichael

Facilities Manager


Jason has spent much of his life pursuing extreme sports and is an avid surfer, skateboarder, and snowboarder. He has been a surf and snowboard instructor and enjoys working with young people and engaging them as a mentor. Jason will be coordinating activities and providing support in the residence. 

How to Apply

Please contact Aaron Rumsey
with any questions or to start
an application to our program.
He can be reached at

(800) 588-6898.

You can also find information on getting started HERE




Mailing Address
Cornerstones of Maine

Po Box 1834

Kennebunkport, Maine 04046

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