The (based on evidence) neuroscience against the rise of multiple psychiatric diagnoses
11/04/2023 at 07:04:38
Author: Lucas Galdino
Blog
Despite the widespread number of misconceptions on mental health and psychiatric disorders, neuroscience-based on quantitative evidence has shown effective pieces of evidence against the unique reliability of diagnosis based on behavior manifestation. In fact, the way we study the brain has changed in the last decades. In the field of psychiatric neuroscience, it is common to observe studies with complete opposite results from both behavioral or physiological measures. But, do you know what is a behavioral or physiological measure?
Well, a physiological measure employs the quantitative recording of any biological variable, from the number of red cells in your blood mop slices to the anatomical / functional activity in the brain using fMRI or EEG. From this point of view, behavioral evidence employs the observation of a phenomenon using quantitative or qualitative measures that occur using multiple physiological substrates and result in a physical observation, such as run, move your hand, scream, have lunch, or even have sex (Figure 1).
Figure 1 - Schematic representation of an emergent behavior onset through multiple interactions among physiological substrates and its complex connections.
However, as described before, a behavior (or a psychiatric symptom or disorder) can emerge from multiple complex interactions among the physiology. It can explain the controversial results in neuroscience papers in the psychiatric field, once different physiological measures may emerge the same behavior. To get things straight, Drysdale et al., 2017 described at least four different brain patterns in depressive patients, showing that different physiological interactions could “create” the same symptom (Figure 4).
Figure 2 - Four different functional accounts in both limbic and cortical regions in depressed patients. The size of red and blue balls represents the clustering coefficient in the resting-state functional connectivity of the patients.
Chun et al., (2013) found physiological pieces of evidence on the schizophrenic and bipolar brain using the classic GO/NOGO paradigm through EEG recording. They found several functional similarities into P300 amplitudes across psychiatric disorders, which were both different from the healthy subjects (Figure 3).
Figure 3 - Mean amplitudes of NoGo P300 for healthy controls, bipolar disorder and schizophrenic patients for left visual field stimuli (LVF) and right visual field stimuli (RVF) over the a) frontal midline (Fz), b) central left (C3), c) central midline (Cz), and d) central right (C4).
Otherwise, it is also observed in the opposite pattern: patients with different psychiatric disorders exhibit equal physiological patterns. In this case, the physiological manifestation could emerge different symptoms and then leads to different diagnoses. Thus, in this case, do you think that psychiatrists take into account the exhibited behavior, or the functional/anatomical patterns when prescribing pharmacological or therapeutic approaches?
Lucas Galdino
