Former Liberal leader Lord Steel has spoken of his wife Judy's failing mental health after revealing she has been hospitalised with severe depression for almost a year.

The peer urged urged more focus on the problems of an ageing population as he told how Lady Steel, 76, had been diagnosed with bipolar disorder.

He said his wife's condition meant that he had effectively retired from public life, describing how friends and family had to come to his "rescue".

Lady Steel, a drama producer and novelist, played a key role in her husband's political career since their marriage in 1962.

She was by his side when he was first elected to the Commons in 1965, through his 12 years as Liberal leader in the 70s and 80s and the tumultuous merger with the SDP.

During a speech to the history and civic societies of Dunblane, Lord Steel of Aikwood said: "One result of being tied to home and hospital is that my attendance in the House of Lords has been sporadic.

"I have effectively disappeared from public life, and this is the first speech I have made for six months. I envisaged us both coming to join you this evening, but it was not to be.

"For much of the second half of last year and all of this one, my wife has been in hospital with severe depression, having been diagnosed as bipolar."

Lord Steel, 78, who also served as the first Presiding Officer at the Scottish Parliament between 1999 and 2003, said looking after his wife had made him think and read more about mental health and growing old.

"The experience of living alone has taught me that we are not doing enough to tackle the problem of our growing elderly population and their need for social care," he said.

"I have seen friends who have lost their life partners, but whose children are on the other side of the world; another who has lost his spouse to the emptiness of severe Alzheimer's disease, and other people who are just crippled with loneliness."

The peer voiced gratitude that "although I have never learnt to cook, I have three married offspring living in the Borders and a network of close friends who have rescued me."

Lord Steel paid tribute to David Cameron and Theresa May for the focus they have put on mental health issues, saying too many people were 'ignorant' about the problems.

Bipolar disorder, also known as manic-depression, causes huge swings in mood that can leave people lethargic and unable to carry out day-to-day tasks for weeks on end.

The underlying cause of the disorder is unclear, but it is thought around one in 100 adults will be diagnosed with it at some point in their life.