Depression is the most common psychiatric comorbidity in epilepsy with a lifetime prevalence of between 30 - 35%. Depression has a greater negative impact on quality of life (QOL) in people with epilepsy (PWE) than seizure frequency, but remains underrecognized and undertreated. A lifetime history of depression has a negative influence both on response to antiepileptic medication and response to resective surgery. Depression may also be associated with decreased adherence to antiseizure medication. Comorbid depression increases the risk of suicidal ideation and behaviour; it is associated with premature mortality, including death from suicide. There is a bidirectional relationship between epilepsy and depression, suggesting that there might be underlying mechanisms predisposing to both conditions. This implies that having epilepsy increases the risk of developing depression and having depression increases the risk of developing epilepsy.