David has cared for his wife since she started drinking after the birth of their only child more than 20 years ago.
He describes caring for Karen (not her real name) as "moving from one crisis to the next".
To protect his young son from her excessive drinking, David reluctantly sent him to boarding school.
Despite the challenges, David has stayed with his wife, although he says their marriage stopped being a husband-and-wife relationship a long time ago.
Through the years, three things have given David the strength to keep going: the Samaritans helpline, his diary and exercise.
Karen had postnatal depression, which was later diagnosed as bipolar disease. She gave up work because of her illness and started drinking as a way of coping. "She would drink quite a lot of whisky, which would make her very aggressive," says David.
She drank more when she was stressed – for example, when their son was leaving for or coming home from boarding school. "He would see her at her worst," says David.
David sometimes had to call an ambulance for Karen after she'd had a nasty fall, or call the police when she became violent towards him and their son. "We just moved from one crisis to the next," he says.
As Karen's drinking showed no sign of stopping, David decided to move out of their west London home with his son, who was then aged 10. "Karen's family said my first responsibility was to my son and that I should take him away from the hell at home," says David.
Living separately has helped prevent the family permanently splitting up. "My caring role has been one of trying to keep the family going," he says.
David, who lives near his wife, says his life has become "incredibly isolated". But, as a self-employed tradesman in the decorating business, he says he is happy spending time alone.
David now spends 10 hours a week caring for Karen. She also receives support from social services, including home help, through her Disability Living Allowance.
"The drinking still goes on," says David. "She no longer drinks whisky, but she drinks strong lager. She's been in for detox so many times that I know she's never going to stop drinking. I accept that."
David gets support from his local Carers Trust centre, which has offered him a range of carer support services, including information and emotional support. It has also given him the chance to meet other carers in similar situations and to share his experiences with them.
When he needs to let off steam, he finds the Samaritans offer immense relief. "Just to be able to talk to somebody who's genuinely interested and sympathetic is a tremendous help," he says. "I feel completely relieved afterwards."
He keeps a diary, which he writes in every day. "It's like having somebody there to talk to," he says. He also finds swimming very therapeutic. "I swim away my frustrations when I've had a hard time."
One of his frustrations as a carer is not being recognised by social services as being part of his wife's care team. "I'm rarely consulted about her care," he says. "They are missing out on my enormous experience of my wife's history and my familiarity with the pattern of her condition."
If you look after someone, go to Care and support for information, advice and support, or call the Carers Direct helpline on 0300 123 1053.