Is it possible to identify a psychiatric disorder using a structural brain scan? According to a team of researchers from Europe and Australia this can indeed be the case. In a recently published study in NeuroImage, researchers Carles Soriano-Mas et al. demonstrate that structural brain scans can identify subjects suffering from obsessive-compulsive disorder (OCD) with a 93.1% classification accuracy (for a whole-brain comparison). In addition, individual variance in OCD symptom severity was correlated with the measured neural differences. In other words, the more you suffer from OCD the more you are likely to stick out in the analysis as an oddball, compared to a healthy norm.
Here is an image showing the structural differences between OCD patiens (n=72) and healthy controls (n=72):
In the image, the heat scale indicates regions where OCD patients differ significantly from controls at the whole brain level. Interestingly, when the researchers focused on the most intense regions the predictive value of the brain scans dropped to 76.6% accuracy. This means that a whole-brain approach is the optimal for determining whether a subject is suffering from OCD.
The study clearly demonstrates that neuroscience is moving in the direction of single-subject analysis, and the application of advanced analysis methods to determine whether a given individual is structurally (or functionally) within the normal range. If the means are there, when will we see them being used — and misused? After all, if a brain scan has the close to 100% accuracy of telling whether a person is suffering from OCD, why not use it in the clinic right away? Or better, why not expect applicants to an important company position take such a scan? After all, if you suffer from OCD, you are less likely to be able to be in such a position, right? And while we’re at it, why not try for a similar approach for depression, anxiety, stress and introversion?
Are we right in being sceptical towards the application of such measures of psychic health? Methodological problems aside, should such a measure provide a robust assessment tool, why should we not use it? After all, psychological testing is really aimed at uncovering who people are. Apply for a top position and you are likely to be submitted to psychological and cognitive profiling. If scanners provide a better accuracy, would it not be preferable to use this method? Since society has decided to allow psychological and IQ testing, such measures should really be just another improved method. As a consequence, we should not be surprised to see them being used pretty soon — if they are not already in the stores.
The solutions are far from clear in the muddy waters following the blazing trail of neuroscience. As neuroscientific methods move along and create new opportunities, new problems arise, too. What is important is to bring these issues up front in the media and other forums of such debate. Neuroethics is as important as ever.