Lindsey Ellefson is Lifehacker’s Features Editor. She currently covers study and productivity hacks, as well as household and digital decluttering, and oversees the freelancers on the sex and ...

Cognitive models of post-traumatic stress disorder (PTSD) posit that negative post-traumatic cognitions (that is, maladaptive appraisals of the self, others and world in relation to the trauma and its ...