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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 Executive Director


Josh is a licensed clinical psychologist who has spent 20+ 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 ocean based activities. 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. Since being in Maine, Josh has also become a familiar face in the surf lineup. This has resulted in numerous surfing outings for our residents over the years.

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Jake Gelles, Psy.D.

Co-Founder and Executive 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. 

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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. 

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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.

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McKenzie Close

Human Resources and Administrative Manager

McKenzie joined Cornerstones of Maine in April of 2018 as an Administrative Assistant. Soon after joining the team, McKenzie found her calling in our Human Resources and Administrative department. McKenzie's current work at Cornerstones of Maine is focused on managing our Administrative Department with a key role in managing Human Resources and the CARF accreditation process. McKenzie has a passion for the work she does and in her free time she can be found reading, birding, boating, and spending time with her family and friends.


Sabrina Marshall

Marketing Coordinator

Sabrina joined the Cornerstones team in early 2022 as the Administrative Coordinator, bringing with her a diverse background in administration and marketing. Flourishing in creative operations and strategic efforts, Sabrina shifted from her role in administration, into the role of Marketing Coordinator in January 2023. Currently, Sabrina masterfully oversees our integrated marketing efforts and provides support to our Admissions Department. Sabrina was born in Canada, raised in Missouri, and now has made her home in Portland, Maine for the last 4 years. She has a passion for community engagement and thrives on involvement & connection with her neighbors. Outside of Cornerstones, she volunteers as a peer support facilitator with The Center for Grieving Children. When she's not working or volunteering, you can find her adventuring around the coast with her pup Sir Oliver, reading, going to concerts with friends, practicing yoga and meditation, or tending to her houseplants. Sabrina has a BS in Human Environmental Sciences from the University of Missouri and holds a 200 hour Yoga certification.

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Jason McMichael

Facilities Manager


Jason has been a part of the Cornerstones of Maine team since our humble beginnings in 2016. After working as a Program Coordinator and Residential Advisor, he shifted into the Facilities Manager role. He is a jack of all trades and oversees the grounds of all three residences and our Kennebunk office, ensuring our buildings and equipment are safe and functional. Jason designed, renovated, and opened our Portland residences after successfully managing the facilities at our flagship residence, Fairfield Hill. On top of his operational duties, he is American Red Cross Certified and is a CPR and First Aid trainer for Cornerstones. Jason resides in Kennebunkport, Maine with his wife and three kids where they enjoy organic farming and permaculture. He lives an outdoor lifestyle and can be found surfing, hiking, sailing, snowboarding, and camping in the beautiful state of Maine and beyond. 

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