Thousands more people with mental health conditions could qualify for benefits after a Supreme Court case.
A charity celebrated a "landmark moment" in today's ruling - the first ever to involve Personal Independence Payment (PIP) in the UK's highest court.
Technically the government won on a "limited" point in the case, brought by a 47-year-old man known as 'MM'.
But five judges, led by Supreme Court President Lady Hale, also said benefit chiefs should interpret a key rule on qualifying for PIP more broadly than they currently do.
Mind said this detail of the ruling is crucial, and could help thousands of people who struggle in social situations.
MM was rejected for PIP because assessors said he didn't "need social support" to engage with other people.
Instead assessors said he only "needed prompting" to engage with people - a definition that carries fewer points under the scoring system for PIP.
The Department for Work and Pensions (DWP) defended the decision on two counts.
First, the DWP said "social support" meant someone trained and experienced in assisting people - not just a friend.
And secondly, the DWP said the "supporter" has to be present at the time someone is trying to engage socially.
But the five Supreme Court judges said this second part of the definition was too narrow.
They wrote: "Social support is likely to take many different forms, depending on the individual needs of the claimant,.
"It is undesirable to attempt to prescribe, in the abstract, which other forms of support will be sufficient.
"It will be a question of fact and degree, and is something that will have to be worked out on a case by case basis."
Mind spokeswoman Sophie Corlett said: "This is a landmark moment in the ongoing battle to make sure disabled people are supported through our benefits system to live well.
"Far too many are struggling to claim benefits they need because of draconian assessments, which often fail to take fully into account the impact a mental health problem can have.
"Mind hopes, that, with this ruling, thousands more will be able to benefit from much needed help.
"We are very proud to have intervened in support of the individual who took this case on behalf of thousands of people with mental health problems.”
A DWP spokeswoman said: “We are pleased that the court recognised that there must be a need for social support to be provided by a trained or experienced person.
"We will carefully consider the full judgment so that we, working with disabled people and stakeholders, implement it fully and fairly, so that claimants get the PIP support they are entitled to.
“Supporting disabled people and those with mental health conditions is a priority.
"That is why PIP is a better benefit for people with mental health conditions compared to Disability Living Allowance; the proportion who get the higher rate of PIP is five times higher than under DLA.”
