We started a relationship that was to last until the end of 1980 when I left London to move to New York. And he was, in many ways, the reason why I left London. I was by then 30, still deeply in love with him but longing to have children. He, on the other hand, never wanted to get married or have children. What was touching is that he saw this not as a badge of independence and freedom like many men but as a character flaw, almost a handicap. As he wrote in 1983 in his book Enthusiasms, which he movingly dedicated to me even though we were no longer together: “What fear of revealing, of vulnerability, of being human, grips us so fiercely, and above all why? What is it that, down there in the darkness of the psyche, cries its silent No to the longing for Yes?”

It was a No that often coincided with retreating into depression — the “Black Dog” that he described as “that dark lair where the sick soul’s desire for solitude turns into misanthropy”. No wonder he loved cats so much. “Above all,” he wrote once, “I love the detachment of cats, their willingness to be loved but not to respond beyond a certain, very clearly defined point; no cat ever gave its entire heart to any human being.” And no wonder I decided to move not just cities, but continents. Our lives in London were so inextricably intertwined that in December 1980 I left for America. A quarter of a century later I can still feel how tough and painful that decision was. ...

-- Sunday Times (here), 15th August 2004

I didn't know that Levin used the Churchill term for depression - Black Dog - and shared his love for cats. There must be something in all that.