Double blind / Edward St. Aubyn.

Enhanced descriptions from Syndetics:

Double Blind follows three close friends and their circle through a year of extraordinary transformation. Set inLondon, Cap d'Antibes, Big Sur, and a rewilded corner of Sussex, this thrilling, ambitious novel is about the headlong pursuit of knowledge--for the purposes of pleasure, revelation, money, sanity, or survival--and the consequences of fleeing from what we know about others and ourselves.

When Olivia meets a new lover just as she is welcoming her best friend, Lucy, back from New York, her dedicated academic life expands precipitously. Her connection to Francis, a committed naturalist living off the grid, is immediate and startling. Eager to involve Lucy in her joy, Olivia introduces the two--but Lucy has received shocking news of her own that binds the trio unusually close. Over the months that follow, Lucy's boss, Hunter, Olivia's psychoanalyst parents, and a young man named Sebastian are pulled into the friends' orbit, and not one of them will emerge unchanged.

Expansive, playful, and compassionate, Edward St. Aubyn's Double Blind investigates themes of inheritance, determinism, freedom, consciousness, and the stories we tell about ourselves. It is as compelling about ecology, psychoanalysis, genetics, and neuroscience as it is about love, fear, and courage. Most of all, it is a perfect expression of the interconnections it sets out to examine, and a moving evocation of an imagined world that is deeply intelligent, often tender, curious, and very much alive.