Member, working party for developing guidelines for controlled (selected) clinical trials, Dept. of Drugs, National Board of Health and Welfare (NBHW)
Member of Medical Advisory Committee, Swedish Cancer Registry, NBHW
Member of the Urological Board, NBHW
Member of the Nobel Assembly
Member, Board, Epidemiologic Center (EpC) National Board of Health and Welfare
Member Governing Board, European Academy of Cancer Sciences
International member of the American Association for the Advancement of  Science

Fellow, American Psychological Association (Divisions 12 and 29)

Fellow, American Academy of Behavioral Psychology

Founding Fellow, Academy of Cognitive Therapy (ACT)

Fellow, International Academy of Suicide Research

Fellow and Distinguished Practitioner, National Academies of Practice (Psychology)

Member, Board of Advisors, Tragedy Assistance Program for Survivors, Washington, DC,2011 to Present

Member, American Psychiatric Association, Expert Consensus Panel, Suicide Risk, 2011 to Present
 

American Association for the Advancement of Science (AAAS)
American Association for Cancer Research (AACR)
The NCI/CCR Fellows and Young Investigators Association
NCI, Cancer Prevention Faculty member
NCI, Cancer Molecular Targets Faculty member
NCI, Lung and Aerodigestive Cancer Faculty member
NCI Intramural Advisory Board (NCI Postdoctoral Fellows Representative)
Lymphoma Research Foundation
New Jersey Technology Council/Biomarkers and Diagnostics

Membership of the Royal College of General Practitioners (UK)
Membership of the Hong Kong College of Family Physicians
Fellowship of the Royal College of General Practitioners (UK)
Founding Member of Faculty of Travel Medicine
Royal College of Physicians and Surgeons (Glasgow, UK)
Fellowship of the Royal Australian College of General Practitioners

Member of the Royal College of Obstetricians & Gynaecologists(MRCOG)
Member of the Royal Australian College of Physicians(MRACP)
Fellow of the Royal Australian College of Physicians(FRACP)
Honorary Fellow of the American College of Obstetricians & Gynecologists(FACOGHon)

Member Eastern Division Executive Committee
Member Affilliates and SAS Doctors National Committee
Member Faculty Committee General Adult Psychiatry

Member, Endocrine Society
Member, American Society of Reproductive Medicine (ASRM)
Member, American College of Obstetrics and Gynecology (ACOG)
Member, Internal Medicine Resident Society (IMRS), Beirut, Lebanon
Member, Lebanese Medical Student International Committee (LMSIC)
Member, Red Cross, Beirut, Lebanon
Member, Standing Committee on Reproductive Health including AIDS (SCORA), Beirut, Lebanon

Hellenic Society of Biochemistry & Molecular Biology
Hellenic Society of Biological Sciences
Association of Greek Chemists
Hellenic Society of Clinical Chemistry & Clinical Biochemistry
Association of Greek Biologists
American Society for Biochemistry and Molecular Biology

Member, American Psychological Association
Member, Australian Psychological Society
Member, International  Academy of Sex Research
Member, American Association of Sexuality Educators, Counsellors and Therapists
Member,The Australian Centre for Addiction Research.