This study contributes to the growing body of knowledge on mental health in the aftermath of disasters by examining depressive symptoms among residents of the U.S. Gulf Coast region 6 years after the onset of the Deepwater Horizon oil spill (DHOS). Using data from the Survey of Trauma, Resilience, and Opportunity in Neighborhoods in the Gulf (STRONG), we test how social support and ties to the fishing industry are related to the likelihood of a positive depression screen. The results show that, among most residents of the Gulf Coast region, social support holds an inverse relationship with the likelihood of a positive depression screen. However, among fishing households, greater social support is associated with a higher probability of screening positive for depression. By showing that fishing households with greater social support are more susceptible to depressive symptoms in this setting, our results uncover a potentially important mechanism that contributes to the unique vulnerability of fishers, which in turn holds implications for differential impacts across social groups in environmental disaster contexts.