J Schizophr Res. 2017; 4(1): 1030.
Psychopathology is the Science of Symptoms and Signs of Mental Disorders, USA
*Corresponding author: Ahmed Aboraya, Psychopathology is the Science of Symptoms and Signs of Mental Disorders, USA
Received: April 12, 2017; Accepted: April 19, 2017; Published: April 26, 2017
Inspired by Barrios’ classification of psychopathology (descriptive, experimental and psychodynamic) , psychopathology can be expanded into the following 4 subtypes :
- Qualitative psychopathology (descriptive, phenomenological): focus on the form of symptoms. Examples: types of hallucinations (auditory and visual), types of delusions (paranoid, somatic, grandiose…etc.).
- Quantitative (numerical) psychopathology: assigning numbers to symptoms and signs. Example: Duration of auditory hallucination: (1) < 1 hour, (2) 1-4 hours, or (3) > 4 hours per day. Quantitative psychopathology is useful in measuring severity of symptoms, efficacy of treatment, hypothesis testing and other research inquiries.
- Etiological psychopathology: focus on the causes of symptoms. Are auditory hallucinations due to PTSD or a brain tumor?
- Experimental psychopathology: the study of the relationship between an individual’s psychopathology and objective measures such as hormone level or a brain imaging procedure.
At the turn of the twentieth century, Kraepelin conceptualized the disease model of dementia praecox (schizophrenia) and his classification model was enshrined in Western psychiatry for more than a century . The disease model of schizophrenia included three core symptoms (delusions, hallucinations and disorganized thoughts) that were included in all diagnostic systems because they were the most frequently reported by patients . The inclusion of three different groups of symptoms into the disease model of schizophrenia goes against the tenet of the disease model of classification because two patients with totally different symptoms can have the same diagnosis. In 1970, Robins and Guze published a seminal article proposing five phases of achieving valid classification of mental disorders: clinical description, laboratory study, exclusion of other disorders, follow-up study, and family study . The main point of Robins and Guze evidence-based approach is to create homogeneous groups so that researchers and clinicians can study etiology, pathogenesis, and treatment. The DSM diagnostic criterion for schizophrenia, which follows the disease model, does not identify homogeneous populations because patients with different presentations satisfy the official criteria. That explains why after forty five years, the Robins and Guze approach did not solve the problem of classification of schizophrenia .
Another failed attempt to salvage the disease model of schizophrenia is the delineation of schizophrenia subtypes (paranoid, disorganized, catatonic, undifferentiated, and residual), which have shown to be unreliable and inconsistent over time . Eventually, the DSM-5 dropped the schizophrenia subtypes altogether and replaced them with “schizophrenia spectrum.” The model of schizophrenia as one disease has failed researchers and clinicians over the span of the 20th century.
If one wonders why it has taken psychiatry so long to discard a single disease model of schizophrenia, Keshavan et al. has the answer: the relative recency of developments in neuroscience . During the last three decades of the 20th century, there has been an explosion in neuroscience and brain imaging techniques allowing scientists to study brain structures and function even at a cellular and molecular level. Structural imaging (CT, MRI), functional imaging (fMRI), Positron Emission Tomography (PET), Single Photon Emission Tomography (SPECT), Magnetic Resonance Spectroscopy (MRS), genomics, pharmacogenomics, biomarkers, endophenotypes, epigenetic modifications, genetic variants and translational neuroscience technologies are some examples. There are new advances in neuroscience that will lead to “neuroscience-informed nosology” [8,9]. Kendler used a broader term, “scientifically based psychiatric nosology,” which will guide researchers and clinicians toward new classification of psychosis and other mental disorders in the 21st century .
Today, most experts agree that schizophrenia is not one disease, but many distinct diseases with overlapping symptoms . I think it is time to move away from the failing disease model of schizophrenia and march into experimental psychopathology research. Uncovering the biological bases of individual symptoms may prove to be as or more helpful than studying constellations of symptoms (syndromes) in order to understand the pathophysiology of the illness .
I opine that neuroscience-informed nosology contains three essential components (A, B, C):
A. Core Psychopathology: Mental health system exists because patients come to doctors with symptoms and signs; it is a starting point . Until recently, the reliability of measurement of individual symptoms and signs has been neglected. With the publication of the Standard for Clinicians’ Interview in Psychiatry (SCIP), more than 180 symptoms and signs of adult psychopathology have been reliably measured [2,14,15]. More research is needed to identify reliable items for eating disorders, attention/deficit disorder and personality disorders.
Here is an example of a reliable psychopathology item:
MC1. Auditory hallucinations:
Do you hear noises (like music, whispering sounds) or voices talking to you when there is no one around?
Are the voices like a real voice or just thoughts in your mind?
Do voices ask you to do things?
0 Patient has no auditory hallucinations.
1 Patient has auditory hallucinations.
2 Patient has auditory hallucinations with command.
B. Experimental psychopathology: The correlation of psychopathology and objective measures starts with individual item(s), followed by carefully selected groups of items in sequence.
- One-item experimental psychopathology: In psychosis, researchers start with patients with only one symptom, such as auditory hallucinations, and examine the correlation between auditory hallucinations and brain changes.
- Selected two-item experimental psychopathology: Researchers can select patients with two symptoms together (e.g. auditory hallucination and visual hallucination) and examine their correlations with brain changes.
- Selected multiple-item experimental psychopathology: After performing adequate one-item and two-item experiments, researchers may decide to examine the brain changes in patients with several symptoms such as tangentiality, delusions and auditory hallucinations.
As experimental psychopathology research advances, researchers can use the epistemic iteration principle [previously used by Chang  in the science of temperature and applied to psychiatric nosology by Kendler ]. In essence, epistemic iteration is a scientific process with three sequential steps. First, science is built on what has been done before. Second, science advances with a bottom up approach (one-item experiments, then two-item experiments, then multiple-item experiments). Third, as scientific knowledge accumulates successive iterations and revision of experiments leads to a better approximation of reality. Kendler proposed using epistemic iteration in scientifically based psychiatric nosology, leading to “more accurate approximations of the reality of psychiatric illness” .
C. Neuroscience-Informed Nosology: based on the information generated from psychopathology experiments and epistemic iteration, researchers will eventually identify several diseases that constitute what we call the “schizophrenia spectrum” today.
Modern psychiatric nosology research in the 21st century is based upon experimental psychopathology research and has already yielded with promising results [17-21]. Measuring the symptoms and signs of psychopathology items reliably at the level of individual items and correlating them with the brain changes in vivo is the right approach to unveil the mystery of psychiatric disorders such as the “schizophrenia spectrum.”
- Berrios G. The History of Mental Symptoms: Descriptive Psychopathology since the Nineteenth Century. Cambridge, Cambridge University Press. 1998.
- Aboraya A, Nasrallah H, Muvvala S, El-Missiry A, Mansour H, Hill C, et al. The Standard for Clinicians' Interview in Psychiatry (SCIP): A Clinician-administered Tool with Categorical, Dimensional, and Numeric Output-Conceptual Development, Design, and Description of the SCIP. Innov Clin Neurosci. 2016; 13: 31-77.
- Craddock N, Owen M. Molecular genetics and the Kraepelinian dicotomy: one disorder, two disorders, or do we need to start thinking afresh? Psychiatric Annals. 2010; 40: 88.
- Kendler KS. Phenomenology of Schizophrenia and the Representativeness of Modern Diagnostic Criteria. JAMA psychiatry. 2016; 73: 1082-1092.
- Robins E, Guze SB. Establishment of diagnostic validity in psychiatric illness: its application to schizophrenia. Am J Psychiatry. 1970; 126: 983-987.
- Keshavan MS, Clementz BA, Pearlson GD, Sweeney JA, Tamminga CA. Reimagining psychoses: an agnostic approach to diagnosis. Schizophrenia research. 2013; 146: 10-16.
- Sedler MJ. Foundations of the new nosology. The Journal of Medicine and Philosophy. 1994; 19: 219-238.
- Keshavan MS. Classification of psychotic disorders: need to move toward a neuroscience-informed nosology. Asian J Psychiatr. 2013; 6: 191-192.
- Keshavan MS. Nosology of psychoses in DSM-5: inches ahead but miles to go. Schizophrenia research. 2013; 150: 40-41.
- Kendler KS. An historical framework for psychiatric nosology. Psychological medicine. 2009; 39: 1935-1941.
- Tandon R, Nasrallah HA, Keshavan MS. Schizophrenia, "just the facts" 5. Treatment and prevention. Past, present, and future. Schizophrenia research. 2010; 122: 1-23.
- Ozomaro U, Wahlestedt C, Nemeroff CB. Personalized medicine in psychiatry: problems and promises. BMC Med. 2013; 11: 132.
- Keshavan MS. How endophenotype data are best combined with clinical information? Schizophrenia bulletin. 2015; 41: S21.
- Aboraya A. The Validity Results of the Standard for Clinicians’ Interview in Psychiatry (SCIP). Schizophrenia bulletin. 2015; 41: S103-S104.
- Aboraya A, El-Missiry A, Barlowe J, John C, Ebrahimian A, Muvvala S, et al. The reliability of the standard for clinicians' interview in psychiatry (SCIP): a clinician-administered tool with categorical, dimensional and numeric output. Schizophrenia research. 2014; 156: 174-183.
- Chang H. Inventing Temperature: Measurement and Scientific Progress. New York, NY, Oxford University Press. 2004.
- Pinkham AE, Liu P, Lu H, Kriegsman M, Simpson C, Tamminga C. Amygdala Hyperactivity at Rest in Paranoid Individuals With Schizophrenia. The American journal of psychiatry. 2015; 172: 784-792.
- Padmanabhan JL, Tandon N, Haller CS, Mathew IT, Eack SM, Clementz BA, et al. Correlations between brain structure and symptom dimensions of psychosis in schizophrenia, schizoaffective, and psychotic bipolar I disorders. Schizophrenia bulletin. 2015; 41: 154-162.
- Kindler J, Jann K, Homan P, Hauf M, Walther S, Strik W, et al. Static and dynamic characteristics of cerebral blood flow during the resting state in schizophrenia. Schizophrenia bulletin. 2015; 41: 163-170.
- Frankle WG, Cho RY, Prasad KM, Mason NS, Paris J, Himes ML, et al. In vivo measurement of GABA transmission in healthy subjects and schizophrenia patients. The American journal of psychiatry. 2015; 172: 1148-1159.
- Nozaki S, Kato M, Takano H, Ito H, Takahashi H, Arakawa R, et al. Regional dopamine synthesis in patients with schizophrenia using L-[beta-11C]DOPA PET. Schizophrenia research. 2009; 108: 78-84.