For some time, the startling increase in the number of people on sickness and invalids benefits has been as vexing as it is worrying. Have we become a sickly society? Is this the logical consequence of an ageing population? The relentless rise in the number of such beneficiaries - from 1.2 per cent of the working-age group in 1980 to 4.8 per cent today - suggested other factors were at work. Indeed, it is now apparent that a major factor is mental illness. Psychological disorders, led by stress and depression, accounted for the entire increase in sickness benefits and a third of the increase in invalids benefits from 1996 to 2002. This has obvious implications for those charged with getting as many beneficiaries as possible back into the workforce.

In part, the surge in the number on sickness and invalids benefits is down to an increased recognition of mental health problems. But modern society is also extracting a toll. Many of the doctors who acknowledge the problem have been all too ready to issue a medical certificate so such people could receive a long-term sickness benefit. This overlooked not only the treatable nature of the problem but, more especially, the importance of work for a person's health.

The latter verity has tended to be somewhat overlooked of late. It needs to be reasserted. Happily, it has just been highlighted by the Royal Australasian College of Physicians, which, in a position statement, noted that "the evidence is compelling: for most individuals, good work improves general health and wellbeing and reduces psychological stress". The college points to a recent British review, which found the beneficial effects of work outweighed any risks, with the benefits much greater than the harmful effects of long-term unemployment or prolonged sickness absence.

This has particular implications for the Government-appointed working group whose report later this year could form the basis of a major revamp of the welfare system. Already, it has identified the sick and disabled, with sole parents, as the beneficiary groups on a most fiscally unsustainable path. Its task is to find a recipe for helping sickness beneficiaries back into the workforce where previous attempts have come up short.

Six years ago, the previous Government introduced the Paths (Providing Access to Health Solutions) plan, which aimed to remove, reduce or manage the health problems that were preventing beneficiaries from working. It was not a total success and, in general, New Zealand has trailed other countries in this area. Doubtless, the Danish model of strong support for people to be in work will be one that is studied by the Paula Rebstock-chaired working group.

Australia and Britain have also introduced active support systems to help the sick and disabled back to work. As well as a changed mindset, these require, practically, the allocation of supportive case managers in welfare agencies. That entails a significant expense and Britain and Australia have, quite reasonably, also introduced punishments to enhance the chances of beneficiaries finding work.

The Government may blanch at the cost of such case-managed, multidisciplinary schemes, which may involve the likes of drug rehabilitation. But any calculation must take account of not only the beneficiaries' wellbeing but the various impacts on their families. The method of funding, perhaps the insurance model, is a separate issue. What is not in doubt is the need to change a climate that sees people with common, treatable health problems being certified as permanently unfit to work. Such an approach is way too costly for both the beneficiary and the taxpayer.