鄭健榮博士是香港心理學會臨床心理學組的註冊臨床心理學家、英國心理學會認可臨床心理學家及美國心理學會臨床心理學組會員。鄭健榮博士專為兒童、青少年、成人及長者提供臨床心理診斷、評估及治療服務。

鄭博士於1994年獲香港大學頒授臨床心理學碩士學位，1999年獲香港中文大學頒授臨床心理學博士學位，是首位香港培訓畢業的臨床心理學博士。 鄭博士曾於醫管局多間醫院任職臨床心理學家逾20年，具豐富臨床心理經驗，曾服務的醫院包括葵涌醫院成人精神科/老齡精神科/會診及諮詢精神科、仁濟醫院、明愛醫院、瑪嘉烈醫院、荔景康復大樓等全科住院病人；並於多間醫院之專科門診提供臨床心理服務，其中包括葵涌醫院產後精神科門診、葵涌醫院兒童及青少年精神科飲食失調診所、東九龍精神科門診、明愛醫院身心治療科門診、明愛醫院性心理門診及瑪嘉烈醫院的痛症科門診等。鄭博士在撰寫法庭、工傷、創傷心理評估報告，以及擔任法庭專家証人各範疇也具備豐富的經驗。

鄭博士曾任香港心理學會會長及香港心理學會臨床心理學組主席(2011-2014)。致力推動心理健康教育及「實證為本」的心理治療，並參與帶領同業爭取立法規管香港的臨床心理服務，確保市民能夠享受優質的服務。鄭博士獲邀擔任香港大學李嘉誠醫學院榮譽助理教授多年，亦為香港大學心理學系及香港中文大學心理學系榮譽臨床導師，幫助培訓實習臨床心理學家及精神科醫生之心理治療。

鄭博士一向重視「實證為本」的心理治療及研究，過往曾在多本國際具權威性的[心理學與醫學期刊]發表多項研究結果，其研究範疇包括認知行為治療、失眠、憂鬱症、焦慮症、專注力不足/過度活躍症、痛症管理、沉溺行為、創傷後壓力障礙。鄭博士也撰寫了多本有關心理學的書籍，包括《沉溺行為與治療》、《失眠自療》，以及香港公開大學教科書《社會科學基礎課程 : 心理學與社會學》。 鄭博士曾於多個政府部門、公司社團、大學及專業團體主持有關心理健康的工作坊，並多次接受不同的傳媒專訪，傳遞心理及精神健康之預防及治療訊息。

Dr. Sammy Cheng is a Registered Clinical Psychologist, Division of Clinical Psychology, the Hong Kong Psychological Society, and a member both in Divisions of Clinical Psychology of the British Psychological Society and of the American Psychological Association. He is currently the President of the Hong Kong Psychological Society and had been the Chairperson of the Division of Clinical Psychology (2011-2014), the Hong Kong Psychological Society, leading the industry to promote mental health education and quality clinical psychological services.

Dr. Cheng obtained his master's degree in clinical psychology at the University of Hong Kong, and Ph.D. in clinical psychology at the Chinese University of Hong Kong. He had worked as a clinical psychologist in various hospitals under the Hospital Authority for about 20 years, including Kwai Chung Hospital, Yan Chai Hospital, Caritas Medical Centre, Princess Margaret Hospital and Lai King Rehabilitation Building. He had extensive clinical experience in a number of specialist outpatient clinics, in which he had provided clinical psychological services to patients with post-partum depression, eating disorders, various anxiety and depressive disorders, psychosomatic disorders, pain disorders, dementia, learning disabilities and other psychiatric disorders. He has rich clinical experience in diagnosis, assessment and treatment for children, adolescents, adults and elderly with psychiatric or psychological problems.

Dr. Cheng has served as an expert witness in court while working for the Hospital Authority and in private practice. He is experienced in writing forensic psychological assessment reports for patients with work-related injury and trauma, as well as criminal charges or legal issues.

Dr. Cheng has served as an Honorary Assistant Professor of the Faculty of Medicine, University of Hong Kong and Honorary Clinical Supervisor of both the Departments of Psychology of the HKU and CUHK for many years, offering clinical supervision for clinical psychology trainees. He has always emphasized the importance of evidence-based psychological treatment and research. He has been very active in participating in clinical research with colleagues in the Faculty of Medicine in HKU and various hospitals over the years and published numerous [publications in the international journals] of psychology and medicine. His research interests include cognitive behavioral therapy, insomnia, depression, anxiety, ADHD, pain management, addiction behavior, and post-traumatic stress disorder. His Chinese publications include books titled “Addictive Behaviors and Treatment”, “Self-help Insomnia," and the university textbook, "Foundations of Social Sciences: Psychology and Sociology".Dr. Cheng has served as a trainer in various government departments, corporate associations, universities and professional bodies. He is active in delivering public education through writings, teaching and attending different media interviews.