Licensed and Board-Certified Providers

Scottsdale Mental Health & Wellness Institute is founded by Dr. Roland Segal and Dr. Ehab Abdallah. Both psychiatrists are licensed and have multiple board certifications and over a decade of proving holistic psychiatric treatment and care. They are involved in regional and national professional organizations and have held Medical Directorship positions across the nation. Both Dr. Segal and Dr. Abdallah are Clinical Assistant Professors of Psychiatry with the University of Arizona. Dr. Segal was also recognized as one of the top psychiatric doctors by Phoenix Magazine in 2020.

Managing Partners

Dr. Ehab Abdallah, M.D.

Ehab Abdallah, M.D.

Dr. Abdallah obtained his medical degree from Alexandria University in Alexandria, Egypt. He completed his residency training in psychiatry at West Virginia University.

Dr. Abdallah is a triple board-certified in General Psychiatry, Consultation-Liaison (Psychosomatic) Psychiatry, and Addiction Psychiatry.

Dr. Abdallah is experienced in treating psychiatric illness in people with complex medical/mental conditions and is an expert in addiction medicine. He is passionate about quality care.


Regan O’Brien M.D.

Regan O’Brien M.D.

Dr. O’Brien earned her medical degree from Northeast Ohio Medical University. She came to the Phoenix area in 2015 to complete residency training at Creighton University School of Medicine Valleywise Health Center (formerly Maricopa County Hospital). Over the course of her training, she worked closely with the underserved and became experienced in treating persons with the most complex and serious mental illnesses. Dr. O’Brien’s background also includes a variety of experiences in the outpatient setting caring for patients of diverse cultural, ethnic, and socio-economic backgrounds. Upon completing her four-year residency training, Dr. O’Brien worked at Valleywise Health in Phoenix, AZ as an inpatient psychiatric consultant before deciding to transition to mostly outpatient work. She has a strong background in psychotherapy with special interest in treating young professionals.

Dr. Mehmud Ahmed, M.D.

Dr. Mehmud Ahmed, M.D.

Dr. Mehmud Ahmed is a psychiatrist in, Arizona. He is affiliated with multiple hospitals in the area, including Banner Behavioral Health Hospital and St. Joseph’s Hospital and Medical Center. He received his medical degree from Dow University of Health Sciences, completed his residency in Norwich Hospital in Psychiatry and interned in Internal Medicine at Harlem Hospital Center. Dr. Mehmud Ahmed has been in practice for more than 20 years. Dr.Ahmed will be joining the Practice at the Tempe location.

Nurse Practitioners


Vanessa Plumley, MSN, PMHNP-BC

Vanessa Plumley, MSN, PMHNP-BC is a Board Certified Psychiatric Mental Health Nurse Practitioner. Vanessa received her Applied Science Practical Nursing Certificate in 2017 and then graduated with her Associate of Applied Science Degree in Nursing in 2018 from Northland Pioneer College. Vanessa then graduated from Frontier Nursing University in Kentucky in September 2021 where she received her Master of Science in Nursing/Psychiatric Mental Health.

Vanessa began her mental health journey in 2015 when she started working at Change Point, a level one psychiatric hospital in Show Low, AZ. She began to work as a paraprofessional psychiatric aid for about two years. It was during this time that her passion for mental health began. She began to further her education and move up within the company, working as a Licensed Practice Nurse and then a Registered Nurse. She then went on to work at Valley MentalHealth and Chemical Dependency Hospital in Phoenix for two years. She has worked with individuals suffering from substance abuse disorders, mental health disorders, and those diagnosed with serious mental illness (SMI).

Vanessa has a strong passion for physical health and believes that one’s mind and body are truly connected. It is her goal to holistically help others find their way to a healthy balance both
mentally and physically. Vanessa believes in incorporating the latest evidence-based research to the treatment plan. Her overall approach to care is patient-centered and collaborative. She believes by collaborating as a team that the patient will gain the tools, they need to reach their personal goals. As no one’s treatment is the same, she would like to help you develop your own individualized plan.

Andia Boci

Andia Boci, APRN, PMHNP-BC

Andia Boci, APRN, PMHNP-BC is a board-certified Psychiatric Mental Health Nurse Practitioner. She graduated Summa Cum Laude from Northern Arizona University in 2015 with a Bachelor of Science in Nursing. Later, she continued her studies and graduated with honors with a Master of Science in Nursing in Psychiatric/Mental Health obtained in 2021. Andia has worked in Arizona’s behavioral health hospitals as well as detox centers where she has made a difference with her patients by providing compassionate nursing care to adults, children and adolescents with mental health and substance use disorders. She provides individualized treatment to each patient and utilizes evidence-based pharmacological therapies.


Shelly Ehmann MA, LPC

Shelly has had her Masters in Counseling since 1994. She has worked with families, individuals, and groups for 28 years. She has provided services in the office and in client homes. She has worked with individuals with various traumas and diagnoses. She has provided groups for substance abuse, depression, and domestic violence survivors and perpetrators. Shelly is a Certified Trauma Informed Professional working with several different traumas. Her focus is on person centered and trauma informed care. She uses what therapeutic modality is appropriate for the individual. She comes from a systems theory background and cognitive behavioral therapy, understanding how people and events interact with each other. She works with the client to identify a tailored treatment plan with goals agreed upon with the individual client. She is a laid back but a goal focused therapist. She believes in treating individuals by focusing on what has happened to them. She is warm and interactive with a good sense of humor.

Paula Kaye Martin, LISAC

Paula Kaye Martin has worked in the behavioral health field for over 32 years. Her experience has ranged from group homes, residential care, inpatient psychiatric, homeless shelter services, to in-home and office counseling. She received her B.S., and MS Canyon University. She also holds a Masters in Counseling from Northern Arizona University. She has experience with Children, adults, family, and substance abuse. She currently holds the license of LISAC for the State of Arizona. She has the philosophy of work hard to play hard. She travels often seeing new areas any chance she gets time with her family.