GMT has demonstrated efficacy in several clinical and non-clinical populations that experience deficits in executive functioning, attention, and memory (similar to those seen in MDD and PTSD), including older adults, individuals who have suffered a traumatic brain injury, have ADHD, poly-substance abuse disorder, or spina bifida. In these studies, participants showed improvements in completing every-day tasks (as measured by self-report), as well as improvements in executive functions such as decision-making, working memory and selective attention. Critically, these results were maintained at follow-up (when assessed). Given the previous success of this intervention in remediating frontal-temporally mediated brain dysfunction across clinical populations, the investigators hypothesize that GMT has the ability to target similar cognitive difficulties experienced by those suffering from MDD and from PTSD. The investigators will further examine whether putative improvements in cognitive performance will translate to functional improvements analogous to those seen in other psychiatric populations undergoing cognitive remediation.