Spontaneous Thoughts and Brain Connectivity: Possible Links Between Early Maltreatment and Later Depression

Maltreatment (MT) during childhood wreaks lasting havoc on the developing central nervous system and is one of the most salient risk factors for numerous psychiatric disorders, including depression.1 Early intervention and prevention strategies to improve outcomes of youth who have experienced MT are sorely needed; advancement in this area will require a deeper understanding of the neurobiological trajectory between the occurrence of MT and the later emergence of illness. One approach is to select neurobiological measures that are known to be impaired in the fully fledged disorder and use them to assess youth with a history of MT who have not yet shown impairment. In depression research, an emerging research area is to study spontaneously generated thoughts that occur while awake but at unstructured times, when thoughts tend to wander. Mind wandering has been linked with intelligence, creative thought generation, and resting-state functional connectivity within the default mode network.2 However, in depression, these wandering thoughts can get stuck on negative content3,4 and could represent a core feature of the illness. Therefore, examination of spontaneously generated thoughts, and their neural correlates, is a promising avenue for research seeking precursors of depression in youth with a history of MT.