Even though dreams quite often affect subsequent waking life, the factors which might modulate this type of continuity are poorly understood. Overall, the findings in a sample of 444 participants showed that dream effects on daytime mood were reported by almost all persons to some extent (about 18% of the dreams affected daytime mood) and - as expected - the most influential factors were dream recall frequency, nightmare frequency, and the intensity of positive and negative dream emotions. In addition, thin boundaries and introversion were related to heightened frequency of dream effects on daytime mood. Longitudinal studies using dream diaries might shed light on the question as to whether and how dreams that affect daytime mood are processed by the waking mind (e.g., sharing the dream, thinking about the meaning of the dream) and whether it is beneficial for the dreamer to initiate such processes, even if the mood was negatively affected in the first place.