It is not uncommon for us psychiatrists to spend time questioning our diagnostic categories, constructs and presumptions. While reading draft DSM-5 and debates around ICD-11, one might be forgiven for thinking we are very far from achieving diagnostic criteria of mental illness that are anything near accurate. In times of doubt, I advise a dip into Gogol. Diary of a Madman reminds us that, although we may struggle to capture the entirety of mental illness or draw the nuanced boundaries, we can at least be clear on what constitutes psychosis. On reading this text I am reminded then that the recognition of psychopathology is far easier than definition, and has been for centuries.

Nikolai Gogol was born in 1809 in the Ukraine and spent his early adulthood as clerk in the burgeoning government ministries. His own mental illness, with features of religious mania and depressive stupor, began after the composition of Diary and led to his untimely death in 1852. Thus, it is his own observation (or indeed perhaps untreated psychosis) on which Gogol draws to allow such accuracy of portrayal. We are treated not only to auditory verbal hallucinations in the form of talking dogs, veridical in nature, but delusional mood and primary delusion: ‘I couldn’t get that Spanish business out of my head. How could a woman inherit the throne?’, followed by ‘Today is a day of triumph, There is a king of Spain. He has been found at last. That king is me. I only discovered this today. Frankly, it all came to me in a flash. I don’t understand why, but before this revelation everything was enveloped in a mist…’

The portrayal of the unshakable nature of delusions, evidence gathered to reinforce belief and evidence disregarded that challenges, is striking and maps neatly on to current cognitive models of delusional formation. On transport to the asylum our protagonist retorts: ‘I think I’m safe in hazarding a guess that I’ve fallen into the hands of the Inquisition, and the person I thought was a minister of state was really the Grand Inquisitor’.

At 20 short pages this story is readily accessible, even though written in a different language, set in a culture far from our own and nearly two centuries old. I use it to teach students. I ask them to identify symptoms, discuss how the diary format enables us to have direct access to subjective experience and reflect on treatment of mental illness in the past. This is much more illustrative than any textbook. Above all, I read it to reaffirm that although we have some way to go in psychiatry we are, after all, on the right track.