On Wednesday, a mentally ill remand prisoner, Victoria Robinson, hanged herself with a towel. She'd been imprisoned, awaiting trial, on charges of making threats to kill. It might appear obvious that a psychiatric ward was more appropriate for this woman than a prison. But even within HMP New Hall, West Yorkshire, the pleas of her solicitor for admittance to the hospital wing were refused. She is the fourth woman to have died at New Hall in the past year, and the 14th to have committed suicide in custody since January 2004.

On Thursday, a report from the National Audit Office was published, disclosing that efforts costing pounds 885m directed since 1997 at decreasing the truancy rates in British schools had made no impact on the problem at all. Secretary of State for Education Ruth Kelly believes discipline problems in schools - such as truancy - can be solved by targeting parents. National Union of Teachers leader Steve Sinnott supports her in this belief. He said schools could not "get instant results when parents collude in truancy".

If these two pieces of dispiriting news seem unconnected, they are not. The parents of habitual truants are now considered to be the sort of people who ought to be jailed for their pathetic inadequacy. As our idea of what sort of disruptive activity should be considered criminal expands, so does the prison population - especially women and children. Usually, however, what they really need is psychiatric treatment of their own.

You'd imagine that in this era of self-help-manual mega-sales, therapeutic intervention would be the first port of call for troubled or troubling individuals. You'd be wrong. Unless you have money, or need only a couple of sessions with a therapist, that simply isn't an option.

Tony Blair this week has been making great play on the idea that his government is going to start heaving malingerers off incapacity benefit. Those who are jobless due to mental illness have been particularly targeted. Yet what no one seems to understand is that alongside their pounds 55-74 a week (try living on that, then see what it does to your mental health), most of these people are getting just anti-depressants and - if they're lucky - occasional chats with a social worker. They don't get better because they aren't treated for their problems.

Instead, the Government spends money on tackling what it thinks are symptoms. At the moment, it is encouraging schools to sign up for "modules" teaching young children about various social ills, such as illegal drugs. The fact that those who have mental troubles tend to suffer serious ill effects from drug use is not reflected in this one-size-fits-all approach.

The sad thing is that it would not even be that expensive or difficult to provide much more mental health support. The Alcoholics Anonymous movement proves - and is despised by professionals because of it - that trained amateurs organised into effective self-help groups can be powerful forums in helping people to tackle their problems and take responsibility for their lives. Self-help can never replace medical intervention, but it could work alongside it with great success.

Instead, rather than addressing the mental health problems of individuals, the approach is to nanny the many who are getting on with their lives. Often this is done in the name of "inclusion", or of "care in the community", but usually it is ideologically motivated nonsense that doesn't work.