"A System Not Built for Us": PMDD, Disability Benefits Reform and the Limits of Social Rights

Mhairi Campbell, Lecturer in Law, University of the West of Scotland

Keywords: social security, disability benefits, Premenstrual Dysphoric Disorder, fluctuating conditions, Adult Disability Payment, Personal Independence Payment, social rights

Autumn 2026 is an important moment for disability benefits in the UK. In Scotland, the Government responded in February to the Independent Review of Adult Disability Payment (ADP). It recommitted to a system 'rooted in dignity, fairness and respect', but left changes to eligibility for the next Scottish Government.

At Westminster, the Pathways to Work Green Paper proposed tightening eligibility for Personal Independence Payment (PIP), but those proposals were withdrawn in July 2025 after parliamentary opposition. The Timms Review of PIP are now finalising their recommendations. Their July interim report found that PIP is no longer fit for purpose, and their September emerging recommendations include improving how PIP assesses fluctuating conditions.

Both governments are now asking the same question: can disability assessment be made fair? Our research with people living with Premenstrual Dysphoric Disorder (PMDD) suggests the answer depends on whether reform changes the eligibility rules themselves, not only how they are applied.

What is PMDD?

PMDD is a severe hormone-based mood disorder, recognised in both DSM-5 and ICD-11. It causes debilitating symptoms in the second half of the menstrual cycle, typically for one to two weeks every month. Symptoms include depression, anxiety, irritability, difficulty concentrating and suicidal thoughts.

Around one in 20 people who menstruate are thought to live with PMDD. The risks are serious. In a global sample of 599 people with confirmed PMDD, 72% had experienced active suicidal thoughts and 34% had attempted suicide. A 2026 systematic review of 18 studies across ten countries concluded that people with PMDD are clearly at increased risk of suicidality yet found no studies of treatments to reduce it. People with PMDD are also more likely to have experienced past trauma.

What did we do?

Our study explored the experiences of people with PMDD who applied for ADP or PIP. We ran four focus groups: three with 17 people who had applied for support (four for ADP in Scotland, 13 for PIP in England), and a fourth with three professional stakeholders who support people through the process. Of the 17 applicants, seven were successful the first time, two after mandatory reconsideration or appeal, seven were unsuccessful and one did not complete the application

The numbers are small, but the contrast is striking: all four ADP applicants were eventually successful, while seven of the 13 PIP applicants were not. Scotland's approach may be making a difference, yet ADP applicants still described many of the same barriers.

Why are the rules a problem?

ADP inherited PIP's framework of activities, descriptors and points. Under both PIP and ADP schemes, a descriptor only applies if it is met on more than 50% of days. For someone who is severely unwell for one to two weeks every month, the '50% rule' can leave serious, recurring incapacity just on the wrong side of the line. The Independent Review recommended replacing the rule, but the Scottish Government has left that decision to the next administration.

Our participants also explained that PMDD does not stop when symptoms ease:

You know, even if that's - if you're not having symptoms on they days, it's like the kinda aftermath o' that, isn't it, that you're recovering from. (Person with PMDD, Scotland)

The regulations do allow descriptors to be combined: points can be awarded where two or more together apply on more than 50% of days. Our participants found this hard to evidence, and it was applied inconsistently. The Upper Tribunal for Scotland recently illustrated the problem in LT v Social Security Scotland, overturning a First-tier Tribunal decision that had failed to consider adding descriptors together in this way.

The law does recognise fluctuation in other ways. Under both schemes, a person only counts as able to carry out an activity if they can do it reliably: safely, to an acceptable standard, repeatedly and within a reasonable time. If they cannot, a descriptor reflecting greater difficulty, and carrying more points, applies instead. In RJ, GMcL and CS, the Upper Tribunal held that 'safely' does not require harm to be more likely than not. Decision-makers must consider whether there is a real possibility of harm, taking into account how serious that harm would be.

For a condition where the harm may be self-harm or suicide, this matters. And when the Upper Tribunal in MH held that psychological distress could count for the mobility component of PIP, the UK Government changed the regulations to exclude it. The High Court in RF then quashed that change as 'blatantly discriminatory' against people with mental health conditions. The courts have repeatedly corrected a framework built around physical, stable impairment. Our research shows those corrections are not consistently reaching front-line decisions.

What did we find?

1. Lack of a trauma-informed approach. People found the process challenging, distressing and, for some, re-traumatising. This was evident at every stage, from application to decision letter. One participant described disclosing suicidal thoughts during their assessment:

When I stated that I had been, like, suicidal, I actually got asked "Why I didn't… why I didn't do it?" (Person with PMDD, England)

This matters beyond individual experience. Research on the Work Capability Assessment found that reassessing people between 2010 and 2013 was linked to a rise in suicides, mental health problems and antidepressant prescribing: around six additional suicides for every 10,000 people reassessed.

2. Inconsistent assessment and decision outcomes. Participants felt the criteria were applied unevenly. In some cases, PMDD was not mentioned in the decision letter, even when it was the focus of the application. Mental health symptoms were treated differently from physical ones:

The letter said that "I laughed" so was clearly not depressed. (Person with PMDD, Scotland)

3. Difficulty evidencing a fluctuating condition. The application form made it hard to show how symptoms change across the month:

It's very, very quantified. So there's specific boxes and specific points, and if you have a fluctuating condition, trying to convey that is really difficult. (Professional stakeholder, England)

Medical evidence was hard to obtain, and advice conflicted. Some people were told to describe their worst days, while a professional stakeholder warned that this can make people appear to exaggerate at tribunal.

There is an irony here. Confirming a PMDD diagnosis requires daily symptom records across two cycles, producing exactly the kind of evidence of fluctuation that benefit assessments struggle to use.

4. Unawareness (or lack) of availability of support for the application process. Most participants did not know that help was available. PMDD affects concentration and decision-making, so completing a long application during a symptomatic phase is very hard, and support services are under enormous pressure. A large UK study found that the stigma attached to claiming benefits leads many people to put off applying until they are desperate and puts some off applying at all. The same study found that over half (51%) of claimants said the application process itself had made their mental health worse. For people with PMDD, who are already at serious risk of suicidality, a process that harms mental health and that people go through without support is a particular concern.

Why does this matter?

The Social Security (Scotland) Act 2018 states that social security is a human right and places dignity at the heart of the system. But rights are realised, or not, in everyday decisions made by front-line staff using the categories they are given (Lipsky, 1980). If those categories cannot see a cyclical condition, the right risks becoming symbolic rather than substantive.

Scotland and the rest of the UK are often contrasted: dignity and rights versus conditionality and work activation. That contrast is real, and our ADP participants' outcomes suggest it can make a difference. But both systems share the same structural problem: an assessment model built around stability, applied to people whose lives are defined by variability.

The Scottish response has improved how the rules are applied; it has not changed the rules. The Timms Review risks repeating this. Around 45% of responses to its call for evidence mentioned difficulty capturing fluctuating conditions, yet its recommendations must sit within existing spending projections. Better forms and guidance are welcome. But without changes to the descriptors and thresholds, fluctuation will continue to be managed rather than recognised.

What needs to change?

Our final report makes ten recommendations for reform. For both governments, the priorities should be to:

• reform the eligibility criteria, including the 50% rule, so that frequency, severity and recovery time are assessed together;

• apply the RJ approach to risk explicitly to cyclical conditions, and accept symptom records as evidence;

• embed trauma-informed practice across Social Security Scotland and the DWP, including mandatory training and trauma-informed decision letters; and

• establish independent advocacy and peer support, so that no one has to navigate the process alone.

Both governments now have a chance to move beyond incremental reform, and to build a system that recognises fluctuation rather than merely managing it.

Mhairi Campbell was a member of the Advisory Group to the Independent Review of Adult Disability Payment (2024–2025). The research discussed here was conducted with Lynsay Matthews, Julie Riddell and Eileen Harkess-Murphy and funded by the Royal Society of Edinburgh.