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.

Akshay Lokhande M.D, MHA

Akshay Lokhande M.D, MHA

Dr. Lokhande is double board certified in General Psychiatry and Child and Adolescent Psychiatry. He obtained his medical degree from Grant Medical College in Mumbai, India. He completed his psychiatry internship at Saint Elizabeth’s Hospital in Washington DC. He completed his General Psychiatry residency and Child and Adolescent psychiatry fellowship at the University of Oklahoma Health Sciences Center where he served as the Chief Fellow in his final year of training. Prior to residency and fellowship, he completed a Masters degree in Health Care Administration from the University of Southern California. He has extensive research experience in neuroscience and psychiatry and has been published in peer-reviewed journals.

He takes a biological, psychological and social approach to treatment. He provides compassionate and evidence based treatment through medication management and psychotherapy. He has experience in treating a wide variety of psychiatric conditions. In his free time, he enjoys spending time with his family, cooking, traveling, and hiking. Dr. Lokhande is fluent in English, Hindi and Marathi languages.

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.


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 has a Master’s in Counseling and a Master’s in Leadership. She has worked with provided services to individuals, families, children, and groups since 1990. She uses the strengths Based Philosophy in her counseling and tries to work with the strengths that individuals already have to improve the quality of life. Her experience includes many different modalities that she tailors to the client’s needs that she works with. She has been licensed as an Independent Substance Abuse Counselor since 2004. She is a Certified Trauma Informed Professional. Her goal is to work with individuals to reach the outcomes that they are looking for in their treatment. She is relaxed but goal oriented and uses humor often to work through issues with individuals. She has a philosophy to work hard to play hard. She is an avid traveler and loves to visit new places.

Physician Assistant

Nicole Morin, MMS, PA-C

Nicole Morin, MMS, PA-C, is a nationally certified physician assistant. In 2019 she graduated with honors from the University of Southern California, with a degree in Health and Human Sciences. She relocated to Arizona and completed her Master’s degree in Physician Assistant Studies at Midwestern University in 2022.

Nicole has worked in a variety of medical settings and is dedicated to providing integrated and collaborative care, using evidence-based medicine. Nicole aims to be an advocate for all of her patients with an understanding and compassionate approach.

Alexandra Thomas, PA-C

Alexandra “Lexy” has been a psychiatric provider 2020, working with children, adolescents, and adults. Lexy has worked in both the inpatient and outpatient settings. She completed her undergraduate degree at the University of Arizona studying psychology and Spanish. Prior to attending PA school, she first completed a master’s in biomedical sciences at Midwestern University in Glendale, AZ. Lexy completed her PA master’s degree at Chapman University in Orange, California which is where she found her passion for mental and behavioral health, working in many settings to include drug and alcohol rehabilitation, acute inpatient, and adolescent psychiatry. Lexy is experienced in treating patients 10 and up.

During her free time, she enjoys being active outdoors, exploring Phoenix’s growing culinary scene, and spending time with her family, friends, and French Bulldog.

Administrative Staff

To contact our support staff, including our admissions department, or practice administrator please email them at:
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