Childhood maltreatment increases the likelihood of mental health problems, but outcomes vary widely. The timing of maltreatment may help explain these outcome differences. Specifically, impacts might be stronger during sensitive periods in development when the brain is maximally sensitive to particular types of environmental input. Is there consensus about peak periods of sensitivity to childhood maltreatment? This review led by CGM investigator Erin Dunn, analysis of observational studies in humans found that most studies (75%, or 89 of 118 studies) reported timing effects, but did not identify consistent sensitive periods across studies. The investigators also examined study characteristics to inform a discussion of practices to support future research.