Psychiatric relativity

Recently, the head of the Palistinian health services claimed that the high prevalence rates of Post-Traumatic Stress Disorder (PTSD) that have been reported in Palestine are wrong. The argument behind this claim is that Palestinians live in consistently traumatic conditions. Hence, the “symptoms” they report are normal reactions to extreme circumstances. The idea that these reactions are symptoms of mental disorders results from overlaying Western psychiatric diagnostic systems on a social reality that does not fit them.

The argument is contestable but also interesting. Our culture has medicalized psychiatric conditions to such a great extent that most people think of them as “brain disorders”. Depression, PTSD, and anxiety are basically expressions of something going haywire inside our skulls. Because biology is, in most people’s minds, associated with “hard” scientific categories, this promotes the idea that mental disorders are invariant over cultures. Even though causes and prevalence of PTSD may differ between, say, The Netherlands and Palestine, the disorder is the same.

Does the presumed neural basis of mental disorders have scientific backing? Not as much as you might think. Despite trillions of euros and dollars having been invested in the search for biomarkers in psychiatry, no biological correlates are sufficiently robust to be included as diagnostic criteria in psychiatric classification systems. Instead, most diagnoses require the pattern of symptoms to not just be present, but also to disturb daily functioning in social, relational, and professional contexts. In other words, as long as you’re able to maintain a stable relationship, have a job, and fulfil your social role, many diagnoses are out of reach, whatever biological abnormalities your brain may feature.

Naturally, daily functioning in the social world has to do with the way that social world is structured. If society condemns homosexuality, being gay is more likely to cause anxiety and feelings of worthlessness; if drugs are illegal, drug addicts are more likely to encounter problems with law enforcement; if social reality is a constant warzone, living with anxiety can become the norm rather than the exception. In other words, even in this rather mundane sense, psychiatric diagnoses have a cultural dimension built into them. In a deeper sense, one might also hold that human cognitive schemes are fundamentally shaped by culture and language (the so-called Sapir-Whorf hypothesis), and as such our psychological reality is as much a cultural artefact as it is a biological phenomenon. To the extent that this is true, few culturally invariant categories may exist at all.

What does the situation look like empirically? In the past few years I have been involved in the psychometric analysis of psychiatric symptoms, and have seen dozens of datasets from different countries and on different disorders. My hunch is that the similarities across countries, genders, age groups, and cultures are larger than the differences. However, the available data are limited, and the methodology for investigating this issue adequately still has to be invented. As is so often the case in our field, the empirical jury is still out.