An ongoing study among more than 2,000 adults in the Netherlands has found childhood maltreatment is associated with lower quality relationships later in life.

Past research has also found childhood abuse or neglect can lead to insecure attachment patterns in adulthood, but the current study goes further and suggests these issues arise primarily from severe depression associated with that childhood trauma.

The large cohort has been tracked for nearly a decade already. In the first, second, fourth, and sixth years of the study, researchers assessed participants for depression and anxiety. In the fourth year, the presence of childhood maltreatment was also evaluated. In the ninth year, the participants had the quality of their relationships assessed as well as their attachment styles.

Slightly more than three-quarters of the group reported a history of depression or anxiety.

Similar to previous findings, the authors found respondents with a history of maltreatment also had more severe depression and anxiety.

These individuals reported lower quality relationships and higher levels of insecure attachment, including anxious attachment – exemplified by extreme levels of intimacy with low levels of autonomy – and avoidant attachment – exemplified by high levels of autonomy and discomfort with intimacy.

Researchers tested various pathways to figure out what all these factors might have to do with one another. When controlling for gender, age, and level of education, they found the relationship between maltreatment and poor quality intimate relationships was "fully mediated" by insecure attachment and depression severity.

The researchers modeled six different pathways to see how one leads to the other, and findings indicated two distinct pathways by which this insecure attachment can develop. The strongest pathway connects childhood maltreatment to increased depression severity, anxious attachment, and, finally, to lower quality relationships.

"This pathway indicates that some individuals, who reported being maltreated during childhood, may develop low mood and other depressive symptoms, become more dependent and unconfident, which may be perceived as clingier, and experience more distress in the relationship, which might subsequently affect the relationship quality," the authors write.

The second pathway links maltreatment to depression as well, but this time it is the avoidant attachment that leads to lower quality relationships.

That final step occurs, the authors explain, because partners with avoidant attachment tend to reject intimacy and find it harder to trust and rely on others.

Both of these pathways will need to be replicated in further research, especially if we want to know how and why each factor might lead to another.

While the sample size in this research was quite large, some individuals with severe depression dropped out of the study, which means it might not be fully representative.

What's more, because childhood maltreatment was recalled from the past, it's hard to say if the memories reported are accurate.

Nevertheless, the findings largely align with research showing childhood abuse or neglect can have lingering effects on a person's health and wellbeing later in life.

"Informing parents, teachers, general practitioners, and the general public about the possible destructive impact of childhood maltreatment on mental wellbeing and intimate relations, may lead to better recognition and earlier detection," the authors suggest.

The study was published in Child Abuse & Neglect.