Data and information for NHS mental health services still lags behind that for physical services. Service commissioners and providers need good data and information to manage and improve services, and this is also important to understand the impact and cost-effectiveness of services. Data on NHS mental health services have improved since 2015, and the NHS now regularly publishes data on service activity, spending and waiting times performance. But improvements to mental health data and information are taking longer than planned, with many service providers still not submitting data as required. The Department and NHSE acknowledge that data for mental health services still lag behind that for physical health. We are particularly concerned by the lack of data on patient outcomes and experiences, and poor data sharing, for example, between GPs and mental health trusts. Of 29 integrated care boards surveyed by the NAO, only four said they had all or most of the data they needed to assess patient and user experiences, and none of them felt this in relation to patient outcomes. When asked about the relative value for money and returns on investment, the Department and NHSE could not explain to us the cost effectiveness of their chosen interventions for mental health services. Recommendation 2: In six months’ time the Department and NHS England should write to the Committee, setting out how they will: 6 Progress in improving NHS mental health services • improve the quality and completeness of the data on mental health services, including cost of services and patient outcomes; • ensure these data are shared appropriately to support integrated care systems to improve services locally, including tackling inequalities; and • improve the evidence base on the cost-effectiveness of their investments, for example, on the roll out of mental health support teams in schools.