Purdue University Graduate School
Thesis Document_Shirin Khazvand .pdf (377.14 kB)

Locus of control and depression as mechanisms in the relationship between racial discrimination and substance use

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posted on 2021-01-07, 15:46 authored by Shirin KhazvandShirin Khazvand
Exposure to racial discrimination has been consistently linked with risk for substance use. However, outside of affect-based factors, few other mechanisms have been examined in the literature. One potential candidate is locus of control (LOC). LOC is a learning processes that involves the degree to which an individual attributes rewards as resulting from their own control (internal LOC) versus outside control (external LOC). There is evidence that exposure to stressors is associated with LOC, with a separate body of literature linking LOC with substance use. Thus, it is plausible that LOC may be a mechanism underlying the relationship between racial discrimination and substance use. Additionally, there is evidence that depression is related to LOC. Thus, the relationship between racial discrimination, locus of control, and substance use may also be serially mediated through depressive symptoms. The current study investigated these two pathways among 503 racial/ethnic minority adults aged 18-35 who completed an online questionnaire that included measures on racial discrimination related stress, locus of control, depressive symptoms, and substance use. Results indicated a significant indirect effect of racial discrimination related stress through external locus of control, specifically the chance orientation, on substance use. Moreover, for both domains of external locus of control (i.e., chance and powerful others) a significant serial indirect effect was found through depressive symptoms within the racial discrimination-substance use pathway among racial/ethnic minority adults. These findings expand our understanding on potential mechanisms that underlie the racial discrimination-substance use risk pathway among racial/ethnic minority adults, which may in turn provide important targets for substance use intervention programming for this population.


Degree Type

  • Master of Science


  • Psychological Sciences

Campus location

  • Indianapolis

Advisor/Supervisor/Committee Chair

Tamika C.B. Zapolski

Additional Committee Member 2

Melissa A. Cyders

Additional Committee Member 3

Evava S. Pietri

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