Suitability of the multidimensional scale of perceived social support as a measure of functional social support among incarcerated adults with major depressive disorder.

The multidimensional scale of perceived social support (MSPSS) is a 12-item measure of functional social support (SS); however, the psychometric properties of the MSPSS have not been evaluated in prisoners. We used measures of known-groups validity, convergent and discriminant validity, internal consistency reliability and factor structure to assess the suitability of the MSPSS for measuring SS among 184 individuals in prison in the U.S., who were diagnosed with depression. The MSPSS was correlated with scores on scales measuring related constructs (i.e., loneliness), and uncorrelated with unrelated constructs (i.e., verbal ability). Correlations among items of the MSPSS on the same subscale were large, and small to moderate among items of different subscales. The overall Cronbach's alpha for the scale was 0.93. Confirmatory factor analysis showed that the theorized three-factor solution for the MSPSS (i.e., significant other, family, and friends) provided a good fit for the data. We recommend using the MSPSS to measure perceived SS among incarcerated individuals.