Mark GreenMark Green, MD

Addiction Psychiatrist and Founder

“It is such a relief to find a Doctor who actually listens to me, and understands exactly how I felt. For so long, I’ve felt frustrated, starting different medicines, feeling rushed in and out. It is wonderful to be making some real progress in my life at last.”

Mark graduated (UK version of) summa cum laude in neurobiology and then completed his medical degree at University College London. He knows an awful lot of medicine – general, sleep, pain, neurology and other areas. He came over to NYC for his Psychiatry residency then and Addictions fellowship (Payne Whitney Clinic, New York Presbyterian Hospital, Cornell Medical Center), and later conducted research in the neurobiology of addictions at Rockefeller University. He’s been on Faculty at Cornell (Asst. Prof), Vermont (Asst. Prof), and Harvard (Instructor) Medical Schools. He is dually boarded by the American Board of Psychiatry and Neurology in both general psychiatry and addictions.

Since graduating in 1999, Mark has set up & run addiction treatment programs (NYC, Vermont), directed supreme evidence-based dual disorders programs, overhauled national addictions and pain programs (Kaiser Permanente, Colorado) and treated thousands of patients.

Mark is an expert psychotherapist. He is trained in many modalities: psychoanalytic, cognitive behavioral, solution-focused, motivational, hypnosis, and others. He’s currently receiving training in Accelerated Experiential Dynamic Psychotherapy. Dr. Green’s therapy approach is relational, pragmatic, structured, direct, and emotionally vivid.

He is an expert psychopharmacologist, remaining cutting edge without taking undue risks with you, using what’s tried and tested, and imaginatively minimizing side effects. He often helps people get off med cocktails they’ve been stuck on for years. He sees medications as facilitating psychotherapeutic change.

He has written some articles in neurobiology, psychiatry and addictions, and lectured at major conferences nationwide.

Click here to read his resume


Drew Welch, RN

Nurse, Program Director, family therapist

“He’s the best nurse I ever worked with. We worked together for 6 years at WestBridge and I am really lucky he agreed to work with me at Psych Garden. He’s thorough, conscientious, caring, humble, courageous, honest and wicked smart.”

Drew Welch is a licensed registered nurse & therapist with over 20 years of experience working with individuals with co-occurring disorders as well as their families. He has extensive training in evidence-based practices including motivational interviewing, cognitive behavioral therapies, family therapy, vocational rehabilitation and integrated dual disorders treatment and has supervised and taught others these skills.

Drew was at WestBridge Community Services for 7 years as their nurse care manager, team leader and national wellness coordinator. Prior to that he was the Nurse Manager for the Co-occurring Disorders Unit at Bournewood Hospital.

Drew has more than 20 years of sobriety. He understands how impossible recovery can seem and that no single path works for all. He knows the importance of education, support and hope. These days he uses all his training, experience and passion to help others feel freer, prouder and more connected. Sometimes 12 step approaches help, sometimes CBT, sometimes a focus on exercise and diet (Drew recently completed his first triathlon). Side-by-side coaching can be invaluable to rebuild the self-confidence withered by addictions and psychiatric illness; so he’ll do that too.

Jonathan Entis, PhD

Adults Psychotherapist

Jonathan Entis is a licensed psychologist providing psychotherapy to adults across the age span. His areas of interest are anxiety, depression and other mood disorders, relationship and personality difficulties, addictions, trauma and major mental illness. He has particular expertise in treating individuals who have found other forms of treatment unhelpful or ineffective.

While his training has involved a range of therapeutic models, he approaches each person as a partner in therapy and tailors his approach to the unique needs of the individual.  He tends to work from an Intensive Short-Term Dynamic Psychotherapy (ISTDP) approach. This model involves an active and concentrated focus on emotions and the ways in which blocking or avoiding them contributes to suffering.  ISTDP can be challenging but aims to produce rapid and profound change from the beginning of treatment.  It helps individuals take an honest look at the feelings and experiences that they have not been able to shed so that they can finally move beyond them and live the life they want.

Jonathan did most of his clinical training at Harvard Medical School, including a doctoral internship at Harvard/Cambridge Health Alliance and a placement at Harvard/Massachusetts Mental Health Center, and a post-doc at Tufts University. He holds a PhD from Northeastern University, an MA from Boston College, and a BA from the University of Michigan.

In addition to his clinical work, he maintains an active academic career and has published a number of papers on topics covering severe mental illness, ethics, neuroscience, and psychotherapy.  He has taught graduate and undergraduate level courses at universities across Greater Boston, including Northeastern University, Boston University, and Boston College.  He currently teaches at Harvard Medical School/Cambridge Health Alliance.

Karen MacKenzie, LICSW

Individual, Couples and Family Therapist

Karen is a compassionate, focused and experienced therapist who has special expertise in working with couples and families, including those affected by addictions.

Her training includes Emotionally Focused Therapy, a short-term model proven effective in healing relationships, as well as psychotherapy from relational, systemic and CBT models and community Reinforcement Approach. In addictions work, she has learned from both 12-step and Harm Reduction perspectives and individualizes care.

She uses an experiential and systemic approach to assist clients in identifying patterns of feelings, thoughts and behaviors that occur in times of stress, and to change them so as to achieve success, happiness and intimacy. Karen believes that by collaboratively recognizing, honoring, and building on the strengths and resources clients possess as well as the impact of close relationships, they are able to glean a sense of hope and agency for the future.

Karen was a registered nurse before changing careers, studying psychology (summa cum laude) and then obtaining her masters in social work at Simmons.

Darren Skehan, LMHC

Mental Health Counselor

Darren is a Licensed Mental Health Counselor with over 10 years experience working on complex psychiatric and addictions issues. His ability to partner with clients and families that have struggled to bond with other therapists is informed by his broad training across several evidence-based modalities. Darren has extensive training in several Family Therapies, including CRA-FT and Open Dialogue; and in individual modalities including CBT, Narrative and Mentalization-Based Therapy.

Darren earned his Masters in Counseling Psychology from Boston College. Prior to becoming a therapist he spent a decade working as an educator in Boston-area high schools. Although this career change has been a very gratifying one for him, Darren does occasionally miss having Summers off.

When not in the office, Darren finds abounding joy, intermittent bewilderment and perpetual wonderment in being a dad to his young son and daughter. He is originally from Dundalk, Ireland.

Danielle Green, LICSW

Couples and Family Therapist

Danielle received her MSW from Columbia University in 1993 and completed 5 years of further specialist training in couples and family therapy at the Ackerman Institute for the Family, in New York City. She worked and taught at Cornell Medical Center for 10 years before relocating to Boston to serve as Clinical and Training Director of the Couple and Family Therapy Program, at the Cambridge Health Alliance, Harvard Medical School. There, she trained psychologists, psychiatry residents and social workers and lectured extensively throughout the Harvard system. Danielle is a certified EFT (Emotionally Focused Therapy) therapist and supervisor. Danielle helps couples develop skills to restore trust, communicate and express feelings effectively, understand and resolve differences, and enhance intimacy. It is Danielle’s passion to help couples repair their connections and create secure and lasting bonds with those who matter the most. Danielle also offers supervision to advanced practitioners.

 Percy Ballard, MD

Psychiatrist and Psychotherapist

Percy Ballard, MD is a psychiatrist who graduated from Stanford University and then Harvard Medical School and completed general psychiatry residency training at Harvard Medical School/Cambridge Health Alliance. He is an expert of psychopharmacology and therapy and has, for 10 years, worked in LGBTQ community programs, private practice and therapy collaboratives.

He is Level 1, 2 and 3 trained in Internal Family Systems (IFS) therapy, and uses it regularly in conjunction with medication management. He regularly teaches and presents on the topic of IFS, including several workshops with the founding developer of the model Richard Schwartz, Ph.D.  He develops and co-teaches workshops on implicit bias, and co-hosts a YouTube channel on the psychology and spirituality of love and dating. He is LGBTQ friendly, Kink friendly and Polyamory friendly.

Outside of his career-life, Percy is an avid meditator in the Indo-Tibetan Buddhist traditions, a competitive martial artist of several East Asian systems, and an enthusiastic dancer whenever the opportunity arises.

Kerri KuklentzKerri Kuklentz, MS CRC CPRP, NASM-CPT

Field Coach/ Fitness Coach/ Rehabilitation Specialist

Kerri has more than 10 years experience as a field coach for persons with mental health challenges and addictions. We worked together for many and she was incredibly warm, supportive, inspirational and effective, helping people identify core values, get back to accomplishing, living fully through work, education, social connection and healthy living. Then she left to be a personal trainer and a mom for several years and now we are lucky to work with her again, with these added skills and perspectives. She believes exercise is a key path to building self-esteem, gaining acceptance with one’s body and feelings, and attaining balance in life.

Camillia JoyCamillia Joy

Office Manager

Camillia is the office manager for our practice. She grew up in Idaho with a love for dance, soccer and skiing. After graduating from The Thacher School in Ojai, CA she moved to Portland, OR where she spent 15 years enjoying the city’s eclectic culture and local music scene. In 2008 she and her husband relocated to the Boston area to be closer to family as they started a family of their own. Aside from spending time with her daughter, Camillia enjoys being an active member in the community and manages a large listserv for families in her town. Her compassion and warm personality are a perfect fit with our providers and the desire to make every client at Psych Garden feel welcome.



Miles received his initial training on a farm in rural OK before an internship in Belmont and further training at the Psych Garden. We are honored that he has chosen to continue his studies with us and contribute his warmth, gentleness and insights. He is a hypoallergenic poodle-cavalier mix. Like our other staff, he doesn’t bark or bite.