The death of Ted Hughes, not the suicide of Sylvia Plath, was what tipped their son into his fatal depression, friends said yesterday.

The Times revealed on Monday that Dr Nicholas Hughes, 47, an expert in freshwater fish and the younger child of two of the 20th century’s greatest poets, had hanged himself at his home in Alaska.

Subsequent coverage around the world has homed in on the tragic resonance with his mother’s death in 1963. Sylvia Plath gassed herself by putting her head in the oven at their home in Camden, northwest London, and turning on the taps after first sealing the room where one-year-old Nicholas, and his sister Frieda, 2, were sleeping. The children’s formative years were further disrupted six years later when Assia Wevill, the woman for whom Ted Hughes had left their mother, killed herself and her four-year-old daughter.

However, according to some of Dr Hughes’s oldest friends, it was not until his father, then the Poet Laureate, died from cancer in 1998 that his son began to have serious mental health problems. Joe Saxton, 47, met Nicholas at Bedales school and they remained friends for 33 years. Dr Hughes was godfather to Mr Saxton’s youngest child and visited the family in the Lake District on trips back from Alaska. Mr Saxton writes in a letter to The Times today: “In my view it was the profound impact of Ted’s death and its impact on Nick’s family, relationships, love and emotional security that was the cause of his depression and eventually his tragic suicide.

Times Archive, 1978: In search of Sylvia

The burdens laid on the family and friends of Sylvia Plath are many

• 1963: Book review: The Bell Jar

• Ted Hughes: a brutish metamorphosis, 1970

Related Links

• Sylvia Plath’s son commits suicide

• Obsession set limits on Sylvia Plath's poetry

“Ted and Nick had a bond unlike any other father and son I have seen. They loved the natural world, the outdoors and above all they loved fish. While Ted fished and wrote about them, Nick became a world-renowned fish biologist. So when Ted died ten years ago Nick lost the relationship that mattered most to him.

“The impact of his father’s death was that all the other family relationships in his life were turned upside down. Only then did Nick begin to have mental health problems.”

Dr Hughes’s suicide adds a further chapter to the tormented family history and relationship between the parents, both of whom are regarded as among the finest literary talents of the past century.

The relationship between Plath, the author of The Bell Jar, and Hughes has already been the subject of numerous memoirs and dramas with his perceived maltreatment of her prompting a series of attacks on his reputation and behaviour. For both father and son, their close relationship and their shared sense of wonder at the natural world were vital sources of solace throughout difficult lives. In letters to the critic Keith Sagar, Ted Hughes described magical fishing trips with his son in Alaska, Africa and Iceland. Alaska, he wrote, was a “dreamland” where they “fished alongside bears” and “lay awake listening to wolves”.

After his father died, Dr Hughes would have bouts of depression that left him bereft of strength, unable even to contemplate how a neighbour “could find enough energy to mow his lawn”, Mr Saxton said last night.

He responded as a scientist would. “Nothing happened to Nick without him trying to understand every aspect of it, whether it was working out how fish swim upstream or his own depression. He read every book he could find on the subject and the absolute tragedy is that he understood everything that was happening in his brain inside out. He just couldn’t stop it happening and it was terrible to behold.”

Dr Hughes did what he could to fend off the illness. He took to wintering in New Zealand to escape the long Alaskan nights. In December 2006 he left his post as a professor of evolutionary ecology at the University of Alaska, Fairbanks.

Eighteen months ago he was well enough to climb Scafell Pike, the tallest peak in England, with Mr Saxton and his eldest son, but over the past few months his friends knew that he was again “in a rough patch”. “They were so careful and they had changed his medication, but as one of his friends in Alaska told me, he just fell through the cracks in one brief moment,” Mr Saxton said.

Dr Hughes’s girlfriend, Christine, found his body when she returned from work on Monday, March 16.

Unlike his sister Frieda, who has dealt with their harrowing family history partly by talking about it and scrutinising it in her writing, her poetry and her art, Dr Hughes had always actively avoided the subject.

“I never heard Nick tell anyone about his parentage,” Mr Saxton said. “He wasn’t embarrassed; it just wasn’t something he wanted to be a feature of him. That’s the irony. He spent his life trying to get away from all this, to find a place where he could be himself. Then the stupid bugger commits suicide and starts it all up again.”

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