Microglial dysfunction has been implicated in psychiatric conditions such as depression, anxiety, bipolar disorder, and schizophrenia. Proposed mechanisms linking microglia to these disorders include the overexpression of inflammatory cytokines in response to psychological stressors, which may be particularly relevant to suicidality. Other mechanisms involve abnormal, excessive phagocytosis and synaptic pruning, coupled with insufficient adult neurogenesis. Furthermore, microglial dysfunction may decrease the development of oligodendrocyte progenitor cells, leading to reduced myelination and white matter function, a change especially associated with depression.