Computer modeling of adaptive depression.

Mild, delimited, and adaptive depression may be a specific example of a more general class of mechanism by which intelligent systems--individual, social, and artificial--adapt to dynamic, uncertain, and dangerous environments. Computer modeling, based on connectionist and artificial intelligence planning and learning programming techniques, supports this hypothesis by generating both adaptive behavior and analogs for 10 phenomena associated with depression: global, stable, and internal failure explantation, a cognitive loop of failure rumination, decreased motivation, self-esteem, and self-efficacy, and increased realism, negative generalization, and cognitive change. The idea of adaptive depression can be applied to more than one level of living systems. A better understanding of normal and adaptive depression may lead to a better understanding of clinical depression.