It is well established that high-dose alcohol consumption during pregnancy increases the risk for a plethora of adverse offspring outcomes. These include neurodevelopmental, cognitive and social deficits, as well as psychiatric illnesses, such as depression and anxiety. However, much less evidence is available on the effects of low- and early-dose alcohol exposure on mental health outcomes, regardless of the accumulating evidence that mental health outcomes should be considered in the context of the Developmental Origins of Health and Disease hypothesis. This review will discuss the evidence that indicates low-dose and early prenatal alcohol exposure can increase the risk of mental illness in offspring and discuss the mechanistic pathways that may be involved.