425-279-8500 info@lifestance.com

Our Team

Michael K. Lester

President & Chief Executive Officer

Mike is an accomplished health care executive whose professional experience includes 35 years in the multi-site health care services and pharmaceutical life sciences fields.  As the chief executive officer of multiple companies, he successfully capitalized, assembled top tier management teams and implemented strategic and tactical business plans creating long term value for employees, customers and shareholders.

Prior to founding LifeStance Health, a behavioral health company, Mike was the founder and CEO of Accelecare Wound Centers, a comprehensive wound care and disease management company. Prior to that, Mike was a Venture Partner at Bain Capital and SV Life Sciences, founder and CEO of Radiant Research, a comprehensive clinical research company providing Phase I-IV study conduct and drug development services to the biopharmaceutical industry, founder and CEO of ContinueCare Health Systems, a high tech home and alternate site infusion therapy company and founder and CEO of Preferred Hospital Pharmacies, a successful pharmacy management company.  Mike was formerly a board member and President of the Texas State Board of Pharmacy.  He serves on The University of Texas College of Pharmacy Pharmaceutical Foundation Advisory Council and is a member of the board of directors of LifeStance Health, Inc., Ventec Life Systems, Inc. and is a senior advisor to Silversmith Capital Partners.  He holds a Bachelor of Science in Pharmacy from the University of Texas.

Mike enjoys backcountry flying, boating and fishing.

Gwen H. Booth

Chief Operating Officer

Gwen is a founding member of the LifeStance Health team, overseeing the management of existing facilities and practice groups. Gwen also oversees the integration team responsible for bringing newly acquired practice groups into the LifeStance family of providers.

Most recently, Gwen served as the Chief Operating Officer at Accelecare Wound Centers, Inc. She is an experienced health care executive whose professional background includes 16 years in the clinical and biopharmaceutical industry and multi-site healthcare services space. As a senior leader at several health care service companies she successfully managed multiple locations, developed and implemented successful integration and operation plans, and executed successful growth strategies. Prior to joining Accelecare, Gwen was Vice President, Clinical Pharmacology at Covance, one of the world’s largest and most comprehensive drug development services companies, Vice President, Early Phase Clinical Development of Radiant Research, a comprehensive clinical research company providing Phase I-IV study conduct and drug development services to the biopharmaceutical industry and a member of the MDS Pharma Services management team for 8 years. Gwen holds a Bachelor of Science in Nursing from Creighton University in Omaha, Nebraska.

Gwen enjoys spending time with family, boating, and traveling.

Warren Gouk

Chief Financial Officer

Warren joins the LifeStance Health team with over 25 years of experience building and running finance teams, strategy, sales, business development, administration groups and general company management. As chief financial officer, Warren is responsible for leading the finance organization, including financial planning, budgeting & reporting, tax planning and raising capital.

Prior to joining LifeStance Health, Warren was the Chief Operating Officer at Limeade where he focused on building and leading teams to help scale operations, enhance customer delivery & implementation, drive the customer success organization and manage all aspects of financial reporting and planning. Prior to that, Warren was the General Manager and SVP of LexisNexis Healthcare where he was responsible for managing a strategy to build a large, high-growth healthcare business through acquisitions and organic growth.

Warren holds a Bachelor of Commerce in finance & economics from University of British Columbia and maintains professional designations as a Charter Financial Analyst (CFA) and Chartered Professional Accountant (CPA). When not working, Warren participates in hockey, baseball, skiing, golf and is on the board of the Special Olympics.

Danish J. Qureshi

Chief Growth Officer

Danish is a founding member of the LifeStance Health team, overseeing new site openings and the expansion of LifeStance’s existing footprint into new regions. Danish also oversees the clinician recruiting team, responsible for bringing new clinicians on board to the LifeStance family of providers.

Danish was the former SVP of Strategic Initiatives at Accelecare Wound Centers. While at Accelecare, he oversaw the post-acute and physician employment divisions, growing them respectively into 400 skilled nursing facilities under contract and 100 physicians employed. Prior to Accelecare, Danish was an Associate at Nautic Partners, a Providence RI based mid-market private equity firm. He began his career as a management consultant with Bain & Co. Danish received his BA from Northwestern University.

Danish enjoys classic cars and traveling.

Kevin M. Mullins

Chief Development Officer

Kevin has over 10 years of experience in healthcare, as both an operator and investor. He joined LifeStance Health in early 2017 and focuses acquiring and integrating new behavioral health practices.

Prior to joining LifeStance, Kevin was a Vice President at Summit Partners where he focused on investments in the healthcare services and life sciences sector. While at Summit, he was part of the team that founded MedSpring Urgent Care, which operates 50 urgent care centers in 3 states and was acquired by Fresenius Medical Care. Previously, Kevin worked at Curaspan and in the Healthcare Investment Banking Group at Leerink Partners. He holds a BA in physics and economics from Bowdoin College and a MBA from the Stanford Graduate School of Business.

Kevin enjoys listening to sports radio, CrossFit, biking and all Boston sports.

Michael Goldberg, Ph.D

Division President - Northeast

Michael Goldberg founded Child & Family Psychological Services, Inc. (CFPS) in 1994, and throughout his career has worked to innovate the delivery of behavioral health care in a manner that improves the quality of care, enhances the experience of care for clinicians and clients, improves overall health and reduces overall medical costs.  CFPS has been the pioneer in embedding behavioral health services in primary and specialty medical and educational entities in a manner that effectively integrates with comprehensive outpatient behavioral health sites.  CFPS is largest private outpatient behavioral health practice in Massachusetts.

Dr. Goldberg received a BS in Psychology from Bates College and a MS and Ph.D. in Clinical Psychological from Saint Louis University.  He completed a pre-doctoral fellowship at Boston Children’s Hospital/Harvard Medical School and a post-doctoral fellowship Harvard Medical School.  Dr. Goldberg is a past president and Fellow of the Massachusetts Psychological Association and served as their Director of Professional Affairs. American Psychological Association’s (APA) Society of Clinical Psychology honored Dr. Goldberg with their Blau Award for Early Career Contributions to Clinical Psychology. He is also a recipient of The Ezra Saul Award for Contributions to Psychological Services from the Massachusetts Psychological Association (MPA). Dr. Goldberg received two Presidential Citations from the MPA. and the Heiser APA Award, each recognizing his advocacy efforts.

Dr. Goldberg enjoys spending time with his two adult children and wife, travelling, hiking and Boston sports.


Santiago Tagtachian

Division President - Southeast

Santiago has developed his career as an industrial engineer focused on strategy development and mergers and acquisitions. In 2013 he became part of Georgia Behavioral Health Professionals (GBHP), where he concentrated his time on growth and business development. Santiago joined LifeStance Health’s executive team in mid 2017 through the company’s acquisition of GBHP. He also maintains his role as the Managing Director of GBHP, the largest privately held outpatient behavioral health care practice in Georgia. As Managing Director, Santiago’s focus has been on improving the operational performance through a focus on patient satisfaction. Mr. Tagtachian holds a Bachelor of Science degree in Industrial Engineering from the Instituto Technologico de Buenos Aires and Master in Business Administration from the Darden School of Business at the University of Virginia.

Santiago enjoys working with his wife Ashley and spending time with his 2 children Mateo (10) and Mila (6). He also tries to find time to visit his family and friends in Argentina.