The COVID-19 pandemic has severely impacted the lives of people across the world. There is increasing evidence that the mental health of the UK population was significantly worse as a result of the pandemic and restrictions put in place to stop the spread of COVID-19. Further research has identified groups within the population who were more at risk of an increase in symptoms of depression and anxiety. One of these high-risk groups are those with high levels of autistic spectrum traits (ASTs). Indeed, prior to the pandemic, previous studies have found that mental health conditions such as depression and anxiety amongst those with autistic spectrum disorder or ASTs are highly prevalent. However, of the studies investigating the influence of ASTs on mental health conditions during the pandemic published thus far, most have used convenience sampling, clinical samples, small sample sizes or retrospective reporting of mental health prior to the pandemic. Such methods decrease the validity of the findings, and by using only clinical samples (i.e. only including people who have a clinical diagnosis of autistic spectrum disorder), those who are not able to get a clinical diagnosis due to factors such as socioeconomic status are not represented in the sample, further reducing validity. Therefore, this study will not be using clinical diagnostic data, and instead will use data from a continuous measure of ASTs collected within ALSPAC. Research using birth cohorts such as ALSPAC allow for a comparison of symptoms of depression and anxiety before and after the pandemic, which can help establish whether changes in these symptoms coincide with the pandemic. Furthermore, due to the longitudinal nature of ALSPAC, potential confounding factors such as gender can be adjusted for. This current project will be investigating the influence of Autistic Spectrum Traits (ASTs) on symptoms of depression and anxiety experienced as a result of the COVID-19 pandemic within the ALSPAC population. Further to this, previous literature has highlighted the importance of social interaction and communication when considering the factors related to mental health concerns amongst those with ASTs. Specifically, adults with ASTs who report feelings of loneliness and lack of social contact also tend to report increased symptoms of anxiety and depression. In the context of this pandemic, this factor is highly relevant due to social distancing and self-isolation rules. Therefore, the second part of this study will aim to investigate whether the association between autistic spectrum traits and anxiety and depression depended on changes in social contact as a result of restriction arising from the COVID-19 pandemic.