This chapter reviews a growing body of research indicating that nostalgia is triggered by psychological threat or negative affective states and may thus be a resource people turn to in order to regulate distress or cope with a number of life's challenges, and It also reviews research highlighting the many sensory triggers of nostalgia. Loneliness is clearly a powerful trigger of nostalgia. Hofer determined that nostalgia was a disease because the patients that were longing for home were experiencing a significant amount of distress. Anxiety, insomnia, disordered eating, and sadness were common symptoms of nostalgia. The author and his colleagues conducted an experiment in which they induced different mood states. More resent research on music-evoked nostalgia converges with these experimental findings: when listening to music that was popular during their youth, participants were more likely to report that the music made them nostalgic if they were in a negative mood prior to listening to the music.