Mental Health Minimum Data Set (MHMDS)#
Last modified: 12 Oct 2026
1. Summary#
Data about mental health services was introduced in April 2000 to provide clinical information about adults with mental health issues. Over the years, the mental health dataset has evolved significantly. The Mental Health Minimum Dataset (MHMDS) was used to collect information about adults with mental health conditions, including those with drug or alcohol dependence, between 2003 and 2014. It was replaced by the Mental Health and Learning Disabilities Data Set (MHLDDS) which collected information between 2014 and 2016, and then the Mental Health Services Dataset (MHSDS), which is ongoing. Researchers who are approved to access any of the three mental health datasets will automatically be provisioned all three.
| Dataset Descriptor | Dataset-specific Information |
|---|---|
| Name of Dataset in TRE | NHSE_MHMDS |
| Citation (APA) | Data Services, NHS England (NHSE). (2025). NHS England: Mental Health Minimum Data Set (MHMDS). UK Longitudinal Linkage Collaboration (UK LLC). https://doi.org/10.71760/ukllc-dataset-00679-04 |
| Download Citation | Citeproc JSON BibTeX RIS |
| Series | NHS England |
| Owner | NHS England |
| Copyright | Copyright © (2026), NHS England. Data re-used with the permission of NHS England. All rights reserved. |
| Temporal Coverage in the TRE | 01/2003 - 01/2014 |
| Geographical Coverage | England |
| Participant Count | N/A - Dataset comprises of multiple auxiliary tables |
| Number of Variables | 104 |
| Number of Observations | 42524 |
| Key Link | https://digital.nhs.uk/data-and-information/keeping-data-safe-and-benefitting-the-public/gdpr/gdpr-register/mental-health-minimum-data-set-mhmds-gdpr-information |
| Keywords | Mental health |
| Latest Extract Date | 2024-04-26 |
| Specific Restrictions to Data Use | None |
| Build a Data Request | https://explore.ukllc.ac.uk/ |
2. Metrics#
Click on the plus sign to see the number of participants represented in each dataset.
Table 2: Participants from each LPS represented in the MHMDS dataset in the UK LLC TRE. Note: Individual cohort counts of less than 10 are suppressed to <10 and excluded from total participant counts for datasets.
3. Version History#
| Version | 4 |
|---|---|
| Version Date | 09 Sep 2025 |
| Number of Variables | 104 |
| Number of Observations | 42524 |
| DOI | 10.71760/ukllc-dataset-00679-04 |
| Change Log | 10.71760/ukllc-dataset-00679-04/activities |
4. Documentation#
We are currently building a documentation storage system which will host useful documents related to datasets and data owners. We will surface these documents on Guidebook.
5. Useful Syntax#
Below we will include syntax that may be helpful to other researchers in the UK LLC TRE. For longer scripts, we will include a snippet of the code plus a link to the UK LLC GitHub repository where you can find the full scripts.