Childhood Trauma and Trajectories of Depressive Symptoms Across Adolescence
Authors: Kwong Alex S. F. , Maddalena Jennifer M. , Croft Jazz , Heron Jon , Leckie George 
Published: July 2019

Background

Growth curve modelling such as trajectory analysis is useful for examining the longitudinal nature of depressive symptoms, their antecedents and later consequences. However, issues in interpretation associated with this methodology could hinder the translation from results to policy changes and interventions. The aim of this article is to provide a “model interpretation framework” for highlighting growth curve results in a more interpretable manner. Here we demonstrate the association between childhood trauma and trajectories of depressive symptoms. Childhood trauma has been shown to a be strong predictor for later depression, but less is known how childhood trauma has an effect throughout adolescence and young adulthood. Identifying when childhood trauma (and its severity) is likely to have its greatest impact on depression is important for determining the timing of interventions for depression.

Methods

We used data on over 6,500 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC) to estimate trajectories of depressive symptoms between the ages of 11 and 24. Depressive symptoms were measured using the short mood and feelings questionnaire (SMFQ) across 9 occasions. Childhood trauma was assessed between the ages of 5 and 10 years old, and we estimated population averaged multilevel growth curves of depressive symptoms for exposure to trauma (yes vs no) and then in a separate model, the number of trauma types reported such as inter-personal violence or neglect (coded as 0, 1, 2, 3+). We then calculated what the depressive symptoms scores would be ages 12, 14, 16, 18, 20, 22, 24, between these varying trajectories.

Results

Reported exposure to childhood trauma was associated with less favourable trajectories of depressive symptoms across adolescence, mainly characterised by exposed individuals having worse depressive symptoms at age 16. There was an exposure-response relationship between the number of childhood traumas and trajectories of depressive symptoms.

Individuals exposed to 3 or more types of trauma had substantially steeper and less favourable trajectories of depressive symptoms: becoming worse at a more rapid rate until the age of 18. By age 18, individuals that reported the greatest exposure to trauma (3+ types of trauma) had 14% more depressive symptoms compared to non-exposed participants.

Limitations

This study was subject to attrition, particularly towards the latter ages of the SMFQ.

Conclusion

Childhood trauma is strongly associated with less favourable trajectories of depressive symptoms across adolescence. Individuals exposed to multiple types of inter-personal violence or neglect are at the greatest risk of worsening depressive symptoms throughout adolescence and young adulthood. Individuals exposed to traumatic experiences in childhood should be identified as at high risk of depression and other adverse outcomes as early trauma may disrupt social development and have lasting consequences on mental health outcomes.

The model interpretation framework presented here may be more interpretable for researchers, clinicians and policy makers as it allows comparisons of depression across multiple stages of development to highlight when the effects of depression are greatest.