The present invention relates to a method of a) treating any of depression induced by chronic stress; depression in a subject afflicted with PTSD; anxiety induced by chronic stress; anxiety in a subject afflicted with PTSD; cognitive impairment induced by chronic stress; altered morphology and/or reduced number of GFAP+ cells in hippocampus and/or frontal cortex induced by chronic stress; working memory impairment in a subject afflicted with PTSD; b) inhibiting or reversing loss of GFAP+ cells in hippocampus and/or frontal cortex induced by chronic stress; c) decreasing consolidation of contextual fear memory in a subject afflicted with PTSD; d) enhancing extinction of fear memory in a subject afflicted with PTSD; or e) increasing calcineurin A expression in a subject afflicted with PTSD using a combination of cotinine and an antioxidant.