When I Forgot is a beautifully written and deeply moving debut novel from Finnish journalist and film-maker Elina Hirvonen. The story is told by Anna, who is sitting in a café drinking endless cups of coffee and smoking endless cigarettes, putting off the moment she has to visit her brother Joona in a mental health hospital. Anna's remembrances of the events in her life that have led to this point are interspersed with letters written by Joona in childhood and with stories from the life of Anna's American partner, Ian.

Anna's recollections show us the devastating impact of mental illness on families. Anna begins by quoting from Virginia Woolf's suicide note in which she apologises for the effect her depression has had on her husband, a depression aggravated by the outbreak of war. However, in this novel, the people suffering breakdowns are all men. Anna's grandfather took to drink when he returned from the Second World War. Ian's father is destroyed by his experiences during the Vietnam War. Ian himself breaks down in the aftermath of the destruction of the World Trade Center. Anna's mother is clear that it is the women's role to care for these broken men: 'They need help. We girls are stronger and we'll help them won't we?' But what does being stronger mean? Can one person save another?

The language of the book is simple yet effective. Anna's first words are so expressive of the day-to-day struggle of her life ('I can make it. This day.') Despite the darkness of the novel's subject, there is hope. Anna and Ian are able to share their painful memories and perhaps they can help each other recover from them.

Finally, Hirvonen tackles the difficult subject of 9/11. I'm always wary of the portrayal of this event in novels as it can easily seem false or forced. Here the attacks are presented as the modern form of warfare – we don't go to the battlefield, the battlefield comes to us – but the devastating emotional impact is the same as in past conflicts. Despite the quote from the Metro on the book's back cover, Hirvonen deals with the issue without over-emphasising it or making this feel like a 'post 9/11' novel.