Iain Dale applauds Norman Lamb's move to improving the quality of mental health, but says its a huge problem on both a local and national level

It's not unusual for long-serving MPs to stand down in the middle of a parliament and this week we saw Sir Norman Lamb announce he would be quitting at the next election after 18 years as Liberal Democrat MP for North Norfolk.

I should declare an interest here in that I stood against him in 2005, but despite a rivalry 15 years ago he's someone I have always respected as a genuinely good constituency MP, and also a talented health minister in the coalition government.

One reason he gave for leaving parliament at the comparatively young age of 61 is that he feels he can achieve more in parliament outside it than within it. Think about that for a second, and its implications for our parliamentary democracy in the future. It could mean a dramatic lowering of the quality of MPs who seek to serve us in the future. Frankly, a cursory look across the benches on both sides of the House and you could be forgiven for thinking it's already happening.

Norman Lamb is now going to devote his time and efforts to improving the quality of mental health nationally and in our own region. I remember campaigning alongside him in 2004 when we were both trying to keep open Rebecca House in North Walsham, which was a care centre for people with dementia. The experience of banging our heads against the doors of NHS bureaucracy was a salutary one for both of us.

I remember walking into a meeting of relations of the patients and realising that I was their last hope. I did everything I could, and I know Norman did too, but in the end, we failed them. It wasn't our fault, but the Labour government went ahead and closed the facility anyway. It was criminal. It had only been open for 10 years. That feeling of hopelessness has stayed with me ever since.

Mental health is now firmly on the political agenda and Norman Lamb has done more than most to put it there, both when he was a health minister and since.

It's a massive issue in our own region too. I can exclusively reveal the results of research by Smart TMS about the state of mental health in East Anglia. They found that that a third of us are showing symptoms of depression and anxiety, begging the question - do we need to redefine our understanding of depression?

This new research demonstrates that while on the surface we are appearing to get on with our everyday lives like normal, millions of us are suffering from undiagnosed symptoms of depression-like behaviour, and disconcertedly normalising behaviours that are isolating and limiting to one's productivity and social life. Thirty eight per cent of us in East Anglia spend more time alone and less time with family and friends than we used to. A third of us are less confident than we once were. A total of 29% of us no longer enjoy work as much as we used to and 30% of us feel more anxious in social situations than we used to. A third of us care less about our physical appearance than we used to. A fifth of us cancel plans so we don't have to interact with other people and 18% of us think that spending time with their friends does not bring us as much joy as it used to.

Put together this means that around one third of the population is prone to depression - a frightening statistic indeed, especially when we consider that mental illness costs the economy close to £100 billion a year. Even more frightening is the statistic that 23% of us think we have an undiagnosed mental illness such as depression and 14% of us left a long-term mental health issue untreated over many years in order to avoid prescription drugs.

A lot of work for Norman Lamb to get his teeth stuck into.

Email Iain at iain@iaindale.com or follow him @iaindale