Meet our PROFESSIONAL TEAM
Medical Team

Lawrence V. Tucker, M.D.
Medical Director
Diplomate of the American Board of Psychiatry and Neurology
Lawrence V. Tucker, M.D. is a Diplomate of the American Board of Psychiatry and Neurology, and a Diplomate of the American Board of Addiction Medicine, practicing in pharmacological management of psychiatric disorders and addiction medicine.
Dr. Tucker attended UCLA for his undergraduate degree, where he obtained a B.S. in Physiological Sciences. He then attended UCLA School of Medicine for his Medical Degree and stayed at UCLA for his residency in Psychiatry and Neurology. He has been in leadership roles since 2006 and is a Certified Physician Executive. Prior to attending UCLA, Dr. Tucker served in the United States Marine Corps, Infantry, and served in Desert Storm.
Among the long list of accomplishments, Dr. Tucker feels most accomplished with his blended family of 5 children and his wife of over 13 years. In addition, Dr. Tucker has a private practice in Newport Beach CA. His paradigm of treatment is that he: “Treats a person Not a Diagnosis”. He uses a holistic model and incorporates sobriety, exercise, diet, therapy, supplements, as well as psychopharmacological therapies.

Amanda Ferguson
Board Certified Physician Assistant
Amanda Ferguson, PA-C is a nationally and state certified physician assistant. She completed her Masters of Physician Assistant Practice at University of Southern California with an emphasis on primary care.
While completing her education, she trained at LAC-USC hospital gaining experience with inpatient psychiatric and addiction treatment and management. After graduating, she started working in urgent care, where she gained general medical knowledge and skills. She felt called to pursue a meaningful and impactful career in addiction medicine due to her own family being affected by substance abuse and addiction. She has been part of Dr. Tucker’s psychiatric practice since 2020.

Mary Elmasri
Board Certified Physician Assistant
Mary Elmasri is a board-certified Physician Assistant who has extensive experience in the field of Addiction Medicine and Psychiatry. Mary received her Masters of Physician Assistant Practice at the University of Southern California. She is certified to prescribe buprenorphine containing medications. She believes that addiction should be treated like any other chronic disease, with the proper medication, education, and support. She prides herself in empathetic care to all her patients.

Alexis Burciaga
Board Certified Physician Assistant
Alexis Burciaga PA-C is a board certified physician assistant. She earned her Bachelors of Science in Health Sciences from California State University, Fullerton, motivated by her interest in how a healthy lifestyle can impact quality of life.
Following graduation, she worked as a scribe for a pain management and orthopedic spine surgeon as well as gaining experience as a physical therapy aide. She completed her Masters of Primary Care Physician Assistant Studies at USC. After graduating, she started work in urgent care practicing general medicine and performing procedures in clinic. After a few months in urgent care, COVID started and created an ever changing healthcare landscape which challenged her to constantly adapt and stay up to date on health care practices. She saw the mental toll COVID had taken on her patients while in urgent care as well as struggles with substance abuse. She wanted to focus on addressing these concerns and joined Dr Tucker’s psychiatric practice in 2020 while still working in urgent care. She finds it rewarding to address both the acute and chronic issues of each patient with emphasis on a holistic personalized approach. She has transitioned out of urgent care and works full time with Dr. Tucker. She has found it rewarding to nurture patients’ growth and be a part of their sobriety journey.

Ashley Yusam
Board Certified Physician Assistant
Ashley Yusam is a California licensed, National Board Certified Physician Assistant who recently joined Gratitude Lodge in 2022. She completed her Bachelor of Science (BS) degree in Biology from the University of California, Los Angeles in 2012.
Through her time at UCLA, she worked in the Emergency Department as a medical scribe, which contributed to her interest in pursuing medicine. Ashley then went on to earn a Master of Science in Physician Assistant Practice in 2016 at Rosalind Franklin University of Medicine and Science in Chicago, Illinois. At that time she did multiple rotations in Internal Medicine, Surgery, OB/GYN, and pediatrics.
Ashley was born and raised in Orange County, California prior to continuing her studies in the Midwest. A Southern Californian at heart, she returned to Southern California to continue to advance her career in medicine. In her free time, she enjoys cooking healthy meals, hiking, watching movies, and spending time with her friends and family.
Psychiatric and Addiction Medicine is something that Ashley is passionate about, because of her desire to care for people and their entire well-being. Ashley has many years of experience working in the Chemical Dependency and Psychiatry field, treating and diagnosing patients with mental illness. Ashley works closely with Dr. Tucker and has had extensive training and experience treating patients with substance abuse disorders and complex psychiatric issues. She is able to perform initial and follow up psychiatric evaluations, provide a diagnosis, prescribe medications, and refer for psychotherapy. As a PA, Ashley is able to specialize in several different medical specialties simultaneously. Ashley has previous experience working in Internal Medicine and Urgent Care.

Lori Berkemer
Nurse Practitioner
Lori has worked for Addiction Specialist of Southern California since 2020. She loves caring for patients who are struggling with addictions and co-occurring disorders. Lori earned her Nurse Practitioner certificate from UCLA School of Medicine in 1996. She spent many years working in community clinics practicing women’s health and primary care. During that time she spent two years abroad working for Doctors Without Borders.
Through her time at UCLA, she worked in the Emergency Department as a medical scribe, which contributed to her interest in pursuing medicine. Ashley then went on to earn a Master of Science in Physician Assistant Practice in 2016 at Rosalind Franklin University of Medicine and Science in Chicago, Illinois. At that time she did multiple rotations in Internal Medicine, Surgery, OB/GYN, and pediatrics.
Ashley was born and raised in Orange County, California prior to continuing her studies in the Midwest. A Southern Californian at heart, she returned to Southern California to continue to advance her career in medicine. In her free time, she enjoys cooking healthy meals, hiking, watching movies, and spending time with her friends and family.
Psychiatric and Addiction Medicine is something that Ashley is passionate about, because of her desire to care for people and their entire well-being. Ashley has many years of experience working in the Chemical Dependency and Psychiatry field, treating and diagnosing patients with mental illness. Ashley works closely with Dr. Tucker and has had extensive training and experience treating patients with substance abuse disorders and complex psychiatric issues. She is able to perform initial and follow up psychiatric evaluations, provide a diagnosis, prescribe medications, and refer for psychotherapy. As a PA, Ashley is able to specialize in several different medical specialties simultaneously. Ashley has previous experience working in Internal Medicine and Urgent Care.

Desirée Tucker
Registered Nurse
Holds a bachelor’s of science in nursing, and a bachelor’s degree in health administration. She has worked in mental health and addiction medicine as a nurse in the Veteran’s Affairs dual diagnosis unit. She has also worked in public in-patient psychiatric hospitals, working with adults as well as adolescents, experiencing mental health crisis and substance abuse. Lastly, Desirée has also managed out-patient mental health clinics that specializes in addiction medicine and MAT therapies.
Through her time at UCLA, she worked in the Emergency Department as a medical scribe, which contributed to her interest in pursuing medicine. Ashley then went on to earn a Master of Science in Physician Assistant Practice in 2016 at Rosalind Franklin University of Medicine and Science in Chicago, Illinois. At that time she did multiple rotations in Internal Medicine, Surgery, OB/GYN, and pediatrics.
Ashley was born and raised in Orange County, California prior to continuing her studies in the Midwest. A Southern Californian at heart, she returned to Southern California to continue to advance her career in medicine. In her free time, she enjoys cooking healthy meals, hiking, watching movies, and spending time with her friends and family.
Psychiatric and Addiction Medicine is something that Ashley is passionate about, because of her desire to care for people and their entire well-being. Ashley has many years of experience working in the Chemical Dependency and Psychiatry field, treating and diagnosing patients with mental illness. Ashley works closely with Dr. Tucker and has had extensive training and experience treating patients with substance abuse disorders and complex psychiatric issues. She is able to perform initial and follow up psychiatric evaluations, provide a diagnosis, prescribe medications, and refer for psychotherapy. As a PA, Ashley is able to specialize in several different medical specialties simultaneously. Ashley has previous experience working in Internal Medicine and Urgent Care.
Following graduation, she worked as a scribe for a pain management and orthopedic spine surgeon as well as gaining experience as a physical therapy aide. She completed her Masters of Primary Care Physician Assistant Studies at USC. After graduating, she started work in urgent care practicing general medicine and performing procedures in clinic. After a few months in urgent care, COVID started and created an ever changing healthcare landscape which challenged her to constantly adapt and stay up to date on health care practices. She saw the mental toll COVID had taken on her patients while in urgent care as well as struggles with substance abuse. She wanted to focus on addressing these concerns and joined Dr Tucker’s psychiatric practice in 2020 while still working in urgent care. She finds it rewarding to address both the acute and chronic issues of each patient with emphasis on a holistic personalized approach. She has transitioned out of urgent care and works full time with Dr. Tucker. She has found it rewarding to nurture patients’ growth and be a part of their sobriety journey.
Through her time at UCLA, she worked in the Emergency Department as a medical scribe, which contributed to her interest in pursuing medicine. Ashley then went on to earn a Master of Science in Physician Assistant Practice in 2016 at Rosalind Franklin University of Medicine and Science in Chicago, Illinois. At that time she did multiple rotations in Internal Medicine, Surgery, OB/GYN, and pediatrics.
Ashley was born and raised in Orange County, California prior to continuing her studies in the Midwest. A Southern Californian at heart, she returned to Southern California to continue to advance her career in medicine. In her free time, she enjoys cooking healthy meals, hiking, watching movies, and spending time with her friends and family.
Psychiatric and Addiction Medicine is something that Ashley is passionate about, because of her desire to care for people and their entire well-being. Ashley has many years of experience working in the Chemical Dependency and Psychiatry field, treating and diagnosing patients with mental illness. Ashley works closely with Dr. Tucker and has had extensive training and experience treating patients with substance abuse disorders and complex psychiatric issues. She is able to perform initial and follow up psychiatric evaluations, provide a diagnosis, prescribe medications, and refer for psychotherapy. As a PA, Ashley is able to specialize in several different medical specialties simultaneously. Ashley has previous experience working in Internal Medicine and Urgent Care.

Lawrence V. Tucker, M.D.
Medical Director
Diplomate of the American Board of Psychiatry and Neurology
Lawrence V. Tucker, M.D. is a Diplomate of the American Board of Psychiatry and Neurology, and a Diplomate of the American Board of Addiction Medicine, practicing in pharmacological management of psychiatric disorders and addiction medicine.
Dr. Tucker attended UCLA for his undergraduate degree, where he obtained a B.S. in Physiological Sciences. He then attended UCLA School of Medicine for his Medical Degree and stayed at UCLA for his residency in Psychiatry and Neurology. He has been in leadership roles since 2006 and is a Certified Physician Executive. Prior to attending UCLA, Dr. Tucker served in the United States Marine Corps, Infantry, and served in Desert Storm.
Among the long list of accomplishments, Dr. Tucker feels most accomplished with his blended family of 5 children and his wife of over 13 years. In addition, Dr. Tucker has a private practice in Newport Beach CA. His paradigm of treatment is that he: “Treats a person Not a Diagnosis”. He uses a holistic model and incorporates sobriety, exercise, diet, therapy, supplements, as well as psychopharmacological therapies.

AMANDA FERGUSON
Board Certified Physician Assistant
Amanda Ferguson, PA-C is a nationally and state certified physician assistant. She completed her Masters of Physician Assistant Practice at University of Southern California with an emphasis on primary care.
While completing her education, she trained at LAC-USC hospital gaining experience with inpatient psychiatric and addiction treatment and management. After graduating, she started working in urgent care, where she gained general medical knowledge and skills. She felt called to pursue a meaningful and impactful career in addiction medicine due to her own family being affected by substance abuse and addiction. She has been part of Dr. Tucker’s psychiatric practice since 2020.

MARY ELMASRI
Board Certified Physician Assistant
Mary Elmasri is a board-certified Physician Assistant who has extensive experience in the field of Addiction Medicine and Psychiatry. Mary received her Masters of Physician Assistant Practice at the University of Southern California. She is certified to prescribe buprenorphine containing medications. She believes that addiction should be treated like any other chronic disease, with the proper medication, education, and support. She prides herself in empathetic care to all her patients.

ALEXIS BURCIAGA
Board Certified Physician Assistant
Alexis Burciaga PA-C is a board certified physician assistant. She earned her Bachelors of Science in Health Sciences from California State University, Fullerton, motivated by her interest in how a healthy lifestyle can impact quality of life.
Following graduation, she worked as a scribe for a pain management and orthopedic spine surgeon as well as gaining experience as a physical therapy aide. She completed her Masters of Primary Care Physician Assistant Studies at USC. After graduating, she started work in urgent care practicing general medicine and performing procedures in clinic. After a few months in urgent care, COVID started and created an ever changing healthcare landscape which challenged her to constantly adapt and stay up to date on health care practices. She saw the mental toll COVID had taken on her patients while in urgent care as well as struggles with substance abuse. She wanted to focus on addressing these concerns and joined Dr Tucker’s psychiatric practice in 2020 while still working in urgent care. She finds it rewarding to address both the acute and chronic issues of each patient with emphasis on a holistic personalized approach. She has transitioned out of urgent care and works full time with Dr. Tucker. She has found it rewarding to nurture patients’ growth and be a part of their sobriety journey.

Ashley Yusam
Board Certified Physician Assistant
Ashley Yusam is a California licensed, National Board Certified Physician Assistant who recently joined Gratitude Lodge in 2022. She completed her Bachelor of Science (BS) degree in Biology from the University of California, Los Angeles in 2012.
Through her time at UCLA, she worked in the Emergency Department as a medical scribe, which contributed to her interest in pursuing medicine. Ashley then went on to earn a Master of Science in Physician Assistant Practice in 2016 at Rosalind Franklin University of Medicine and Science in Chicago, Illinois. At that time she did multiple rotations in Internal Medicine, Surgery, OB/GYN, and pediatrics.
Ashley was born and raised in Orange County, California prior to continuing her studies in the Midwest. A Southern Californian at heart, she returned to Southern California to continue to advance her career in medicine. In her free time, she enjoys cooking healthy meals, hiking, watching movies, and spending time with her friends and family.
Psychiatric and Addiction Medicine is something that Ashley is passionate about, because of her desire to care for people and their entire well-being. Ashley has many years of experience working in the Chemical Dependency and Psychiatry field, treating and diagnosing patients with mental illness. Ashley works closely with Dr. Tucker and has had extensive training and experience treating patients with substance abuse disorders and complex psychiatric issues. She is able to perform initial and follow up psychiatric evaluations, provide a diagnosis, prescribe medications, and refer for psychotherapy. As a PA, Ashley is able to specialize in several different medical specialties simultaneously. Ashley has previous experience working in Internal Medicine and Urgent Care.

Lori Berkemer
Nurse Practitioner
Lori has worked for Addiction Specialist of Southern California since 2020. She loves caring for patients who are struggling with addictions and co-occurring disorders. Lori earned her Nurse Practitioner certificate from UCLA School of Medicine in 1996. She spent many years working in community clinics practicing women’s health and primary care. During that time she spent two years abroad working for Doctors Without Borders.

Desirée Tucker, RN
Registered Nurse
Holds a bachelor’s of science in nursing, and a bachelor’s degree in health administration. She has worked in mental health and addiction medicine as a nurse in the Veteran’s Affairs dual diagnosis unit. She has also worked in public in-patient psychiatric hospitals, working with adults as well as adolescents, experiencing mental health crisis and substance abuse. Lastly, Desirée has also managed out-patient mental health clinics that specializes in addiction medicine and MAT therapies.
Clinical Team

Jenni Busse MS, LPSS
Clinical Director

Rachel Barazza MSW, ACSW
Therapist

Kemper Gottshall
Therapist

Markie Steinman
Therapist

Renee Balenti
Case Manager

Antonia Peccole
Case Manager

Kelly Demartino
Case manager

Jenni Russe MS, LPSS
Clinical Director

Rachel Barazza MSW, ACSW
Therapist

Kemper Gottshall
Therapist

Markie Steinman
Therapist

Renee Balenti
Case Manager

Antonia Peccole
Case Manager

Kelly Demartino
Case Manager
Executive Team

Mark Williams
Executive Director

Alex Sadak
Vice President

Richard Mintz
Director of Operations

Claudia Sanchez
Director of Administration

Mark Williams
Executive Director

Alex Sadak
Vice President

Richard Mintz
Director of Operations

Claudia Sanchez
Director of Administration
Operations Team

Brandon Payne
Business Development

Louis Odom
Human Resources

Jonathan Bacak
Lead Technician

Elise Main
Lead Technician

Bella Sinatra
Lead Technician

Brandon Payne
Business Development

Louis Odom
Human Resources

Jonathan Bacak
Lead Technician

Elise Main
Lead Technician
