Individual Specificity of Psychiatric Disorders with fMRI

    Psychiatric disorders have such a high prevalence throughout the world. Further, there is no indication that these disorders will noticeably decrease or cease to exist soon. In the United States alone, the Center for Disease Control and Prevention reports that more than 50% of Americans will receive a diagnosis of one psychiatric disorder or another in their life and that 20% will have to cope with a disorder each year (Center for Disease Control and Prevention, 2018). There has been a substantial amount of recent research that has gauged the plausibility and trajectory of using neuroimaging techniques such as fMRIs in clinical settings to be able to give accurate prognoses and diagnoses to patients. The two articles we will look at here appear to converge onto the same opinion. Together, the researchers appear to form a consensus that current fMRI techniques fail to meet the necessary clinical standards due to being unable to give reliable and accurate results to each individual patient seeking medical answers and greater self-understanding. 

    In the article, “Defining Individual-Specific Functional Neuroanatomy for Precision Psychiatry”, by Caterina Gratton and colleagues, the researchers argued for the implementation of a newer and more advanced fMRI technique in precision fMRI (pfMRI). Their main claim held that conventional fMRI techniques are inadequate at providing clear and accurate individualized results of any type of neuropathology or psychiatric disorder. That is, these neuroimaging techniques show minimal translatability to clinics that are attempting to assess a patient’s current prognosis or create a possible diagnosis. Gratton and colleagues based their view on findings from previous studies that suggested average group functional neuroanatomy in different brain regions using fMRIs is ineffective at observing individual heterogeneity of many psychiatric disorders. Further, fMRI techniques may produce noisy and unreliable results at an individual level. The researchers provide a strong case for pfMRI which involves taking larger sets of fMRI data of individuals to potentially solve the previous inefficiency of fMRI techniques. They are of the opinion that their pfMRI work amounts to the requirements for something to be clinically useful in that the technique should provide greater reliability, stability across contexts, and sensitivity at an individual level for clinical psychiatry. 

    In the article, "Current Challenges in Translational and Clinical fMRI and Future Directions”, by Karsten Specht, Specht presented the current and many difficulties that plague and obstruct the usage of fMRIs in clinical settings for psychiatric purposes. Major problems identified by the researcher rest in the limited understanding of the blood-oxygen-level-dependent (BOLD) signal used in fMRIs as well as how reliable and stable this indirect measure of brain activity is across individuals. That is, the hemodynamic response measured may be influenced by endogenous and exogenous factors that may prove difficult to control for every individual to undergo an fMRI scan and adds to the possible individual variability with fMRIs. There are many confounds that may impact an individual’s fMRI results and accentuate the need for standardization of conditions for patients as well as the subsequent analysis of the results to improve the clinical potential of fMRI usage for psychiatry. Additionally, many disorders are given on a broad spectrum that ranges from normal to severely abnormal, so individuals present themselves with a variety of symptoms. Specht viewed this as one of many focal points to fix as more distinct classifications could, in the future, improve diagnosability of disorders using fMRIs. There was some consideration to meta-analyses and machine learning as potential solutions to the numerous difficulties related to fMRIs. However, much more intensive research was advised before giving serious consideration to either of these two potential solutions. The final thoughts given suggest that the likelihood of clinical fMRI usage for psychiatric disorders should improve soon due to ongoing and future research. 

    Both articles discuss the numerous limitations of fMRIs that restrict their use from clinical settings for diagnosing psychiatric disorders and providing updated changes in the conditions of patients. There are required clinical standards that must be met for clinical use before fMRIs can be used in clinical psychiatry. Many sources of variability such as influences on the hemodynamic response, noise, and insufficient datasets for individuals have been the focus of the research conducted by Gratton and colleagues as well as by Specht. That is, the results of fMRI scans are unreliable at an individual level and not yet appropriate for consideration in clinical settings. Nonetheless, numerous researchers are intensively working to determine how to increase the reliability, stability, and sensitivity of fMRI techniques such that clinics can begin using this neuroimaging technique to better diagnose patients with psychiatric disorders. 

Citations:  

Centers for Disease Control and Prevention. (2018, January 26). Learn About Mental Health - Mental Health - CDC. Centers for Disease Control and Prevention. https://www.cdc.gov/mentalhealth/learn/index.htm#:~:text=How%20common%20are%20mental%20illnesses,some%20point%20in%20their%20lifetime.&text=1%20in%205%20Americans%20will,illness%20in%20a%20given%20year. 

Gratton, C., Kraus, B. T., Greene, D. J., Gordon, E. M., Laumann, T. O., Nelson, S. M., … Petersen, S. E. (2020). Defining individual-specific functional neuroanatomy for precision psychiatry. Biological Psychiatry, 88(1), 28–39. https://doi.org/10.1016/j.biopsych.2019.10.026 

Specht, K. (2020). Current Challenges in Translational and Clinical fMRI and Future Directions. Frontiers in Psychiatry, 10. https://doi.org/10.3389/fpsyt.2019.00924