Dr Julian Lewis: I join others who have congratulated my hon. Friend the Member for Daventry (Mr Boswell) on securing the debate. I particularly congratulate him on the measured and compassionate way in which he addressed the subject.

I should state for the record that I am not a medical doctor. Like the hon. Member for Stroud (David Drew), my knowledge of the matter comes entirely from the experiences of friends, relatives and others who are close to me. Because of the prevalence of mental health problems in society, we all have such experiences on which to draw.

I recall the Friday in December 1997 when I introduced a Mental Health (Amendment) Bill after having been drawn second in the Private Member’s Bill ballot. It was the usual set-up for business of that sort, with a sprinkling of hon. Members in the Chamber. I believe that, just a week earlier, the person who had been drawn first in the ballot introduced his Bill to ban hunting with dogs. Hon. Members may remember that, on that occasion, the Chamber was heaving with people who were concerned to express their opinion on what is, of course, a very important issue about which many hold passionate beliefs. However, I felt then and still feel today that there is a mismatch between the concern shown for desperate people and that shown for hunted foxes.

Even today, for this most important debate, there are only seven hon. Members in the Chamber: four Conservatives, one Liberal Democrat and two from the Labour Party, including the Minister. I appreciate that time limitations and the fact that we are not considering legislation have something to do with that. Nevertheless, I believe it indicates that mental health, despite its importance, is undervalued.

For the Minister's benefit, I wish to flag up early the two main issues about which I spoke way back in December 1997 and about which I shall speak today: the importance of separate therapeutic environments for the treatment of people who suffer very different forms of mental illness, and the importance of abolishing mixed-sex wards in psychiatric units.

As my hon. Friend the Member for Daventry said, traditionally, the problem was swept out of sight and people were, sometimes over-zealously, confined to institutions. However, we all know that the pendulum has swung in the opposite direction, sometimes too far, and that people who need the support of an institution or at least the knowledge that an institution is available for what I believe was called the revolving-door technique no longer have it. Previously, people could be out in society but, if they felt an episode coming on, they could go into an institution for respite or treatment – it used to be said, perhaps flippantly, for an MOT service – to recharge their batteries and become stabilised before venturing out into the world again. One of the effects of the pendulum swinging to such an extent against the institutionalisation of people with mental health problems was that beds were then no longer available for those who needed them either in the long term or on a revolving-door basis.

I shall give an example from my constituency, but will not go into constituency matters to anything like the extent that my hon. Friend the Member for Rayleigh (Mark Francois) did with his customary assiduity. There was a large mental hospital on the Tatchbury Mount site before I lived in New Forest, East. It had a very good reputation, but in succeeding years, more and more of the Tatchbury site, which was intended for the therapeutic welfare of people with mental health problems, has been taken over by the administrators of local medical services. I do not draw any conclusions from that about people's state of health, but it has been indicative of a trend and I am glad that a state-of-the-art acute unit is now being built on that site for clients in the New Forest area and beyond who may need an in-patient stay in years to come.

There are two broad categories of sufferer from mental health problems. There are those whose affliction tends to make them aggressive or psychotic and those whose affliction or illness tends to make them vulnerable and delicate. What concerned me in 1997 when I introduced my Bill was that in-patient facilities had been so contracted that, if someone fell into either category, there was no guarantee that if they were admitted they would not be cheek-by-jowl with someone in the other category of vulnerability. To be more specific, someone suffering from a potentially suicidal, depressive condition could have found themselves on the same ward as people suffering from illnesses that made them psychotic and aggressive.

I cannot think of anything worse from the therapeutic point of view for someone in a state of extreme, suicidal, clinical depression than to be in such an environment. A dilemma would arise for the doctors and families of people in that condition as to whether it was more risky to leave them out in society where they might kill themselves or to put them in an institution or unit where they would be cheek-by-jowl with people who were unlikely to encourage any form of rapid recovery.

David Drew: Does the hon. Gentleman agree that that dilemma arises not just in hospitals but in prisons where there are the same pressures and people suffering from mental illness are also incarcerated?

Dr Lewis: I do indeed. I have not studied the subject, but I strongly suspect that there are people in prison today who would be in mental hospitals, not prison, if there were more facilities for in-patient admission to those hospitals.

As I said at the outset, I am not medically qualified to comment on these things, but I want to make an observation about what is sometimes called “depression”, as it has increasingly made an impression on me as I have become acquainted with people who have suffered from it. There is a closer relationship between the physical state of the body – the chemical state of the body, in particular – and the state of mind of an individual than is commonly recognised.

It is unfortunate that the word "depression" is used in two entirely different senses. It is used in the purely psychological or subjective sense, when someone says, "I am feeling down", "I am feeling upset", "I am feeling unhappy", "I am feeling extremely unhappy" or, "I am feeling depressed". Hearing that said in isolation always inspires the reaction: "Ah, well, if you look at it this way…”, “Cheer up!”, “Get your act together”, or “Show an effort of will – you can snap out of it". That is one category of depression, and the word "depression" is commonly used in that sense. For that reason, clinical depression is underrated because it shares the same descriptive term.

When people suffer from what I referred to earlier as potentially suicidal, clinical depression, it can often have an entirely physical cause. My mind goes back to the histories that I used to read about secret agents in enemy territory who were captured and deprived of sleep night after night in order to break them down. The strongest and most courageous people would inevitably crack if they were deprived of sleep for a sufficient period of time.

Much of what passes for clinical depression today is actually caused by shock or trauma, or something that has upset the chemical balance of someone's constitution and destroyed his ability to sleep soundly so that he is in a state of mental decline. All the talking, counselling and cognitive therapy in the world will not do anything to help unless the chemical problem can be addressed. It is unfortunate that these two very different categories of "depression" are lumped together by a common terminology.

Finally, I want to talk about mixed-sex wards. In February 1999, I initiated a debate on this topic, in which I paid tribute to a group of women users led by Cath Collins and based at the Maudsley hospital. Even then, the women were campaigning for new local units that would ensure that people of opposite sexes in a vulnerable mental condition were not put together on wards in circumstances of intimate closeness and sharing facilities.

I recently heard that the women's continuing struggle over a certain unit that concerned them has been successful. That is progress of a sort, but I want the Minister to assure us that there will be no concealment of the figures that show which trusts have succeeded in doing away with mixed-sex wards in psychiatric units, and which trusts persist in trying to keep them going because they believe that it is normal for men and women to mix even in extreme circumstances.

In preparing for the debate, I had a quick look on the internet at newspaper cuttings about sexual assaults, including rapes, that have taken place in mixed-sex wards, and there are too many cuttings, even from the last year or two, for me to run them off my computer database conveniently.

I ask the Minister two questions. First, does he accept in principle that there should be separate therapeutic environments for the treatment of people with very different types of mental illness in in-patient units? Secondly, will he guarantee that, when inquiries are made into which trusts and health authorities have succeeded – and which have not – in abolishing mixed-sex wards in psychiatric units, the data will be forthcoming?