Modern functional brain imaging techniques can be a dynamic process of looking at psychopathology

Modern functional brain imaging techniques are available to psychiatrists and are promising modern-day 'telescopes' to explore in vivo brain activity. Modern psychiatric neuroimaging suggests that only phenomena that may be seen and mathematically computed throughout the scan are real. As imaging techniques have grown ever more sophisticated, they have become in some cases surrogates for nature, rather than representations of it. Such a neuro-realistic approach is, therefore, grounded in the belief that psychiatric imaging enables us to capture a visual proof of brain activity.

However, nearly 3 decades after Johnstone's first computerised axial tomography of the brain of schizophrenics, no consistent or reliable anatomical or functional alterations have been unequivocally associated with any mental disorder, and no clinical application is currently available for psychiatric neuroimaging. No available article has ever addressed in a comprehensive way the methodological and theoretical limits and the high cost-to-benefit ratio of imaging techniques in clinical psychiatry. The phenomena observed by the scan 'speak hypothetically' about the true nature of psychiatric psychopathology seen in clinical experience. This is forgotten as a result of the seductive nature of pictures.

However, we need concepts that lead our observations. Thus, psychiatrists need to have a concept before looking at the scan (a priori hypotheses). Moreover, as Galileo did with the telescope, when they look through the scan, they also need to close one eye and decide which aspect of the phenomenon psychosis not to observe (methodological reductionism). Also, unlike the movements of the earth, mental disorders are not immutable phenomena and psychiatrists cannot simply rely on methodological reductionism (i.e. decide what to observe and what not to observe) in psychiatric imaging and on a priori hypotheses. The history of psychiatry shows that diagnostic criteria and psychopathological concepts are not eternal entities, but reveal themselves to the observer to be diverse and ever changing. In other words, our concepts of psychosis are developed by what is observed with a scanner. These modern techniques often radically alter the phenomena under investigation, and the exact nature of this alteration is frequently poorly understood.

Only by speaking 'ex suppositione', describing mental phenomena and psychiatric disorders hypothetically, modern psychiatric imaging can become a powerful part of the dynamic process of looking at psychopathology and to ontogenetically develop our knowledge. In this fluid and dynamic course of human knowledge about mental diseases, as the poet Rilke stated: truth is a human construct to unveil what is hidden, each time afresh and never lasting.