Big data is vital for mental health research, which often relies on limited sample sizes. Our extensive dataset covers a wide range of issues from diverse texters, allowing for increasingly detailed analysis as it grows.

Its scale and precision provide unique insights: we can track how concerns shift throughout the day or in response to major event, such as Covid-19. It also helps us spot mental health trends, such as a rise in "virus" mentions in early March 2020, weeks before the UK’s first lockdown.

With a dataset of this scale, advanced NLP and machine learning - including deep learning - enable predictive models for risk assessment and theme identification. As manual review becomes impractical, these methods support large-scale mental health research.

Combined with human-led qualitative analysis, they offer deep insights into mental health across the UK. Early findings from our Imperial College London projects show that NLP accurately predicts conversation themes and texter demographics.