Nurse (BBC2, 10pm)

PAUL Whitehouse has to face up to the difficult task of trying to be funny about mental health, dementia and Alzheimer's, without offending too many of his audience. Once again, he's adopting more personas than an Aviva series of adverts, but the co-writer of Nurse, says: "I don't think mental health is a taboo subject any more. In the past few years so many people have been touched by Alzheimer's, especially because people are living longer."

The bittersweet comedy drama, which started life as a BBC Radio 4 comedy, also stars Esther Coles in the central role of Liz, a community psychiatric nurse. The four, 30-minute, episodes saw Whitehouse again collaborate with David Cummings, who has also contributed to The Fast Show, Down The Line and Happiness. We follow Liz as she does her daily rounds visiting the homes of her patients (or "service users" in today's jargon) and the humorous, sometimes sad and often frustrating daily events as the nurse tries to assess progress, dispense medication and offer comfort and support.

Whitehouse plays another series of memorable characters from elderly Herbert on the cusp of dementia, who takes his medication reluctantly because it hushes the friendly voices in his head, to Graham, an obese and bed-ridden man infantilised by his mother who unrelentingly delivers daily doughnuts to his bedside .

"I've been doing this type of acting for so long, all my life really," says the 56-year-old father of three, whose past characters, including Unlucky Alf, Rowley Birkin QC and Ron Manager, led The Fast Show fan Johnny Depp to call him "the finest actor of all time".

"It was a joy for us to do characters with a real depth and it made us ponder why people go into that world," says Whitehouse.

Viewers' hearts will be touched by Billy, the ex-criminal afraid to leave the house; Ray, the bipolar, long-forgotten rock star whose tenuous fame was the result of a terrible Christmas single, and April, the immobile cat lady oblivious to the stench and squalor of her disgusting flat.

"In any field where there is professional involvement and tragedy, there is also humour," says Whitehouse. "Call it gallows humour or whatever, but there always is. So I don't think we're doing anything that can be construed as laughing at these people."

With some characters, such as Graham Downes, Whitehouse improvised a lot of the dialogue on the spot with Cummings, frantically trying to keep up with the laptop.

"We sit there and slag other comedians off for a couple of hours, it usually gets you in the mood," he adds.

Masterchef (BBC1, 9pm)

HUNDREDS have again applied for John Torode and Gregg Wallace's 11th series with 40 making it through. The first group of five contestants are given one hour and 15 minutes to dazzle the judges with their Calling Card - a well-rehearsed dish which represents exactly who they are as a cook, and demonstrates where their individual talent lies.

The judges favourite two are fast-tracked through to the next round, but the remaining three are in a dog-eat-dog cook-off where the same Calling Card ingredients have to be given a new spin. The final challenge has the remaining chefs cooking for Torode and Wallace plus three MasterChef Champions in the form of 2009 winner Mat Follas, 2010s Dhruv Baker and 2012 champ Shelina Permalloo.

One Born Every Minute (Channel 4, 9pm)

THE Bafta Award-winning series returns from its new home at Liverpool's Women's Hospital, which is the largest and busiest maternity unit in Europe. We meet first-time mum Yvonne and her partner, Gary, who are in their 40s, who thought the opportunity to be parents had passed them by, and they were thrilled to find out they were expecting. Jennifer and Darren were told of their baby's heart defect at the 20-week stage, but won't know how severe it is until she's born.