How is SPECT beneficial to Dimensional approaches in the Assessment and Treatment of Psychopathologies?

Currently, the traditional way of assessing and diagnosing patients is through a categorical approach called the Diagnostic and Statistical Manual of Mental Disorders (DSM). There are many issues involving this approach, mostly because of its lack of validity. It creates distinct mental disorder categories, oversimplifying the complexities of human disorders. In some cases, two people who have the same disorder can present completely different symptom clusters, commonly known as a problem of heterogeneity in psychiatric disorders. Comorbidity is another common issue adding to the layer of complexity in clinical presentation in psychiatric disorders. With many more issues, such as stigma and labeling, the lack of multidimensionality representation, the emergence of other approaches became necessary in the field.

Dimensional approaches, instead of categorical ones became preferred. Particularly, the Hierarchical Taxonomy of Psychopathology (HiTOP) and the Research Domain Criteria (RDoC) are worth mentioning and are approaches that have been getting some traction in recent years.

HiTOP is a system that mental health providers can use to organize and assess psychopathologies better, considering the complexity of psychopathologies and their presentation. This system groups related symptoms together, which is extremely relevant for the high incidence of comorbidity in psychopathologies. Below is an example of how eleven different DSM-5 classes of psychopathologies can be incorporated into the HiTOP. This also helps “diagnose” people who don’t neatly fit into a criterion for a mental disorder, since applying discrete categories to mental disorders does not account for the complexity of human symptomalogy presentation.

RDoC, is an approach to used for researching mental disorders that focuses on understanding the basic dimensions (domains) of functioning across different levels of analysis, such as genes, brain circuits, cells, behaviors, and self-reports. RDoC takes a holistic approach to understanding human functioning and mental health conditions. It encourages the integration of multiple levels of analysis to provide a more comprehensive understanding of the emergence and manifestation of mental illnesses. While this model isn’t utilized for psychiatric disorder assessment and diagnosis, it offers an improved approach to such processes.

SPECT brain scans do not show distinctive patterns for each mental disorder, in other words, it does not prove the existence of distinctive DSM-based criteria for mental disorders. SPECT aligns more accurately with dimensional approaches. Rather than relying on symptom clusters provided by the patients, SPECT could aid in the creation of neurobiological profiles that can be associated with their symptoms, alongside the usage of frameworks such as HiTOP and RDoC. Further, personalized medicine should be the goal, as everyone manifests disorders differently and responds to treatments differently. Treating patients with the same type of medicine/therapy is bound to fail as it does not take their neurobiology and individual differences into account. SPECT is not meant to diagnose patients, but simply aid in guiding clinicians to the right path towards diagnosing and treating their patients. It is important to note that such dimensional approaches are still not covered by insurance companies, which brings me to one of the goals of this blog. By comparing, at least superficially, the DSM with more modern frameworks I aim to persuade the reader to join me in advocating for broader insurance coverage of alternative methods beyond the DSM. I dare say that this advocacy is particularly pertinent to the principle of nonmaleficence, one of the five moral principles of the Code of Conduct every psychologist is obligated to serve (more on this later, stay tuned).