There have been several attempts to subtype depression in prior research, but none of them have gained sustained traction – with the exception of separating seasonal depression as its own subtype. Prior attempts to subtype depression have lacked a convincing theoretical framework. We present the rationale for subtyping depression based on evolutionary psychiatry, arguing that depression is not a single disorder but a heterogeneous syndrome comprising multiple evolutionarily distinct subtypes. From an evolutionary psychiatric perspective, a depressive episode may be (1) a prolonged adaptative response to a specific adaptive problem (thus representing a prolonged version of an adaptive short-term mood change); (2) a maladaptive state arising from an environmental mismatch as a result of modern lifestyle; or (3) a by-product of other adaptations. Depressive episodes caused by the latter two can lead to malfunctioning of the mood-controlling system. This can produce a pathological depressive state without any adaptive function. The 12 subtypes of depression discussed in this chapter are: depression induced by (1) infection, (2) long-term stress, (3) loneliness, (4) traumatic experiences, (5) hierarchy conflict, (6) grief, (7) loss of romantic relationship or romantic rejection, (8) postpartum events, (9) the season, (10) chemicals, (11) somatic diseases, and (12) starvation.