Four years ago, The Herald reported on the case of a man with serious mental health problems who had been told inappropriately he was fit to work after being put through an assessment for a disability benefit.

The man, in his thirties, had depression, anxiety and a sleeping disorder, and a history of self-harm when anxious. After learning he had been found fit to work by the Department for Work and Pensions (DWP), he took an overdose and had to be admitted to hospital.

The benefit assessor from the company Atos Healthcare, a nurse, had been given a detailed account of his health problems and the DWP had contact details for the man's GP, psychiatrist and community psychiatric nurse, but had not contacted them.

The mental health charity SAMH said at the time that while strongly supporting return-to-work initiatives for people with mental health problems, it was of critical importance that people did so "only when they are well, and with appropriate support measures in place".

Now in spite of earlier concerns, another case has come to light, this time of a woman in her fifties who killed herself on Hogmanay 2011 after fearing that she would be unable to cope financially as a result of being moved off her £94.25-a-week incapacity benefit and on to £67.50 jobseeker's allowance. The woman, a mother of one, had been living with depression for 20 years and had been an office worker for most of her working life until giving up work because of a deterioration of her illness. She was under the care of a consultant psychiatrist who did not believe she was fit to return to work but, again, Atos staff were not required to consult the woman's GPs or psychiatrist.

This desperately sad case has prompted the mental health watchdog the Mental Welfare Commission for Scotland to criticise the process as "flawed and unreliable", and rightly so. It is now more important than ever that the DWP takes heed. The flaws in the work capability assessment have been the subject of a barrage of criticism and the DWP has responded by making some reforms, but this incident highlights the serious risks of a system that relies so heavily on the outcome of a short interview and questionnaire.

It has been clear all along that those with mental health problems face particular challenges within the assessment process. Since there is no requirement for the health professionals conducting it to seek further medical evidence, the severity of someone's mental health problems might remain hidden. The DWP and Atos say they are still trying to improve the system but, after years of supposed reforms, one-third of appeals lodged against decisions made following work capability assessments are upheld. That is deeply worrying, given that a wrong decision has the potential to lead someone to become dangerously distressed.

It is sadly unsurprising that a system devised to facilitate moving as many people as possible off higher-rate benefits is prone to fail vulnerable individuals. Further reform of this wretched process is still required.