Childhood trauma as a mediator between autistic traits and depression: evidence from the ALSPAC birth cohort.

Autism and autistic traits are linked to higher chances of experiencing traumatic events in childhood and having mental health problems as an adult. However, we don't understand how childhood trauma influences the link between autistic traits and depression in adulthood.Using data from a large birth cohort study in the UK, we tracked up to 9,659 people from birth until age 28 years. We looked at the links between autism, autistic traits, childhood trauma, and depression.We found that all features related to autism were associated with more symptoms of depression between the ages of 10 and 28. Among these, difficulties in social communication were the most strongly connected to depression when they reached adulthood, more than doubling the risk.We discovered that when childhood difficulties and autistic traits came together, the risk of experiencing depression symptoms increased even more. We showed that autistic traits raised the chances of depression both directly and indirectly, by increasing the chance of experiencing childhood trauma.Taken together, our research shows that autism and autistic traits increase the likelihood of experiencing childhood trauma and being diagnosed with depression at ages 18 and 24. Signs of depression that appear in childhood tend to persist into adulthood. The combination of social communication difficulties and childhood trauma has a stronger impact on depression symptoms, indicating that people with these traits may experience more severe depression after facing traumatic events.