Relapse

In the context of addiction, relapse was the return to the initial behaviour. As a recovering alcoholic, Tommy Pierce did occasionally relapse. After Rachel Allan manipulated events so that he would be fired, and spiked his coffee to make it appear as though he was drinking on the job, however, he did not "drink a drop" again. (AUDIO: New Girl)

In medicine at large, relapse was simply a recurrence of someone's past condition. When the Fifth Doctor started acting strangely, since he had been pulled back along his time stream, Tegan Jovanka and Nyssa discussed whether he was having a relapse of regenerative amnesia from his initial trauma on Logopolis, but determined that too much time had elapsed since then. (AUDIO: God of War)

Though he was at first inspired by Amy Pond and the Eleventh Doctor, Vincent van Gogh's depression was hardly beaten, even by a glimpse into his future, and he relapsed into his previous condition, committing suicide on 27 July 1890. (TV: Vincent and the Doctor)