Why do we dream? And why do we have different kinds of dreams at different times?
Many researchers propose that dreams serve to alleviate emotional distress. So by this logic, dreams present distressing scenarios that symbolize similar life events and help dreamers heal from those events while they sleep.
Now a recent study by researchers from the University of Alberta, published in the journal Dreaming, compares the short-term effects of nightmares, which the authors define as primarily containing fear and harm; existential dreams, "in which sadness and separation are salient"; and transcendent dreams, which focus on "awe and magical accomplishment." The results of the study indicate that existential dreams are most strongly related to "self-perceptual depth," meaning that they address weighty topics such as spiritual conviction, life's meaning, and so forth.
Transcendent dreams were most likely to be followed by reports of spiritual release—i.e., the dreamer experienced "refreshing—even ecstatic—freedom from life's entanglements." And contrary to general beliefs about the effects of nightmares, the results of this study indicate that nightmares neither have an impact on waking thoughts and feelings nor are they related to dream-induced self-perceptual depth. This study clearly affirms that different dream effects are attributable to different types of dream, which raises an important question about how we think about dreams:
Most commonly, dream researchers have developed linear adaptive models that describe how certain events (e.g., trauma) influence dreaming (e.g., by causing nightmares) and then how dreaming (e.g., nightmares) causes "adaptive" dream effects (e.g., by facilitating defensive reactions to similarly traumatic events). However, if different dream types have contrasting short-term functions, it may be useful to construe long-term dream function as the capacity of a complex self-organizing system that depends upon the integration of several simpler capacities (Cummins, 1983). From this perspective, the short-term functions of each impactful dream type, when coordinated according to the system's superordinate integrative principles, may subserve a long-term function that is irreducible to the function of any particular dream type. Such a decompositional analysis may help to coordinate evidence of temporal relations between the various dream types.
So a sequence of different types of dreams might be more significant than the effects of any one dream. For example, the authors explain, after a significant loss, dreamers reported more nightmares at first, followed by existential dreams, and eventually transcendent dreams, as though the function of each dream type has a psychological priority corresponding to its chronological order. Thinking about dreams in this way could truly change how we understand how our mind works while we sleep.