Overview The current thesis reports on the design and development of a social support measure which explores the perceived functional social support needs of family members who have a relative with a substance related problem. A mixed methodological approach was adopted to operationalise the concept of social support specific to concerned and affected family members, thus completing the nomological set of instruments required to quantitatively assess the Stress-Strain-Coping-Support (SSCS) theoretical model of addiction and the family. Methods The 75-item self-completion Alcohol, Drugs and the Family Social Support Scale (ADF SSS) was piloted with 10 family members, and the resultant 58-item measure was then subjected to extensive psychometric testing with 132 family members, and qualitative feedback was gleaned from 110 family members. This resulted in the production of a refined 25-item questionnaire. Findings Preliminary findings on the refined 25-item questionnaire indicate satisfactory levels of reliability (internal and test-retest) and validity (content and construct) for the overall measure and each of the three constituent sub-scales: frequency of positively perceived general (α=0.913) and ADF related (α=0.727) functional support, and frequency of negatively perceived ADF specific (α=0.851) functional support. Qualitative information from family members revealed that the questionnaire was experientially applicable to their situation in dealing with the excessive substance use of a close relation. Discussion The significance of producing a concise, psychometrically sound social support measure for concerned and affected family members is discussed in the context of implications for research, theory, policy and practice in the field.