Examined the effect of depressed mood on the accessibility of memories of past real-life experiences of a pleasant or unpleasant nature. By means of a mood induction procedure, 30 students (mean age 19.2 yrs) were made happy on one occasion and depressed on another. The 2 mood states differed significantly on self-report, speech-rate, and recall-latency measures. Stimulus words to which Ss had to associate past pleasant or unpleasant experiences were presented in each mood condition, and latency of retrieval was measured. Time to retrieve pleasant memories, relative to time to retrieve unpleasant memories, was significantly longer when Ss were depressed than when they were happy, suggesting a differential effect of mood on the accessibility of these 2 types of memory. Results are considered in relation to state-dependent learning and activation of memories, and their implications for models and treatment of depression are discussed. It is suggested that cognitive models of depression need to be extended to include a reciprocal relation between thought content and depressed mood. (24 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.