本研究援引「壓力過程」的理論架構，佐以「健康梯度」之相關 文獻，提出兩個主要假設：（1）即便在控制社會人口特徵與社經地位 背景之後，相較於不含信用卡債務的借貸，含有信用卡債務之借貸與 個人的身心福祉具有更強烈且顯著的負向關聯；（2）信用卡債務較有 可能透過增加心理憂困從而提升生理失調，而非藉由生理影響心理。 分析「2007 年台灣社會變遷基本調查計畫：第五期第三次（問卷一： 階層組）」所得的發現支持上述兩個假設。第一，當債務與信用卡無 涉時，雖然仍有可能增加些微心理憂困，但並不至於顯著地提升生理 失調。但當個人借貸之中包含了無擔保、高利率、以提供日常生活消費所需為特徵的信用卡債務時，其與健康在身心兩個層面上皆有顯著關聯。第二，中介分析顯示，當債務與信用卡無涉時，幾乎不會提升生理失調，因其增加的心理憂困相對有限；相較之下，信用卡債務透過心理憂困影響生理失調的相對間接效果既強烈又顯著（相對於無債務以及其他類型債務）。

Drawing on the abundant literature of ‘SES gradient of health’ and the theoretical framework of ‘stress process’, this study proposes two major research hypotheses: (1) carrying credit card debt has a significant and stronger adverse impact on physical and psychological wellbeing than carrying other types of debt, even after adjusting for socio-demographic and socioeconomic backgrounds; (2) it is more likely for carrying credit card debt to be associated with higher level of physical dysfunction through increase in psychological distress, than to be linked to greater psychological distress via growing physical dysfunction. Findings based on “2007 Taiwan Social Change Survey (Round 5, Year 3): Social Stratification” support both hypotheses. First of all, when debt had nothing do with credit card outstanding balances, it was positively predictive of psychological distress only to a moderate extent, but it was not associated with significant gain in physical dysfunction. However, the debt-health relationship was significant and much stronger in terms of both physical and psychological dimensions when any part of the debt was accrued on credit cards. Secondly, the mediation analyses revealed that debt without credit card outstanding balances was barely related to elevation of physical dysfunction given limited increase in psychological distress. On the contrary, the relative indirect effect of credit card debt on physical dysfunction through psychological distress was both strong and significant (relative to no debt at all as well as other types of debt). Alternative models indicated that the relative indirect effect of credit card debt on psychological distress through physical dysfunction failed to reach statistical significance. Implications for future research and public policy are then discussed in detail.