Sonia has experienced depression since she was 17. As a teenager she had problems with an eating disorder and began self -harming. She was admitted to hospital after having taken an overdose of paracetamol when she was in her 20’s. Since that time she has had several admissions to hospital and has been referred to community mental health services at various times. She has tried numerous different antidepressants, but has found it difficult to find the right one for her. Some have lost their effectiveness after using them for a time, and sometimes she has experienced side effects that she has found intolerable.