Issues in Interdisciplinarity 2019-20/Evidence in the Diagnosis of Schizophrenia

Introduction
The ever-increasing influence of neuroscience within the mental health field has brought to light both the shortcomings of psychology's past as well as the obstacles facing psychology as it moves forward. Methodologically speaking, these obstacles are frequently presented as a dichotomy between quantitative and qualitative forms of evidence gathering, the implications of which being their opposition or incompatibility. As a result, it is not uncommon for the so-called competing sides to clash with one another. However, it is the contention of a growing number of holistic practitioners that this forced mutual exclusivity proves not only a mistake, but an impossibility; due partly to the nature of the social sciences, wherein overlapping biological, social, and psychological  influences are the topic of much debate.

This particular matter takes the forefront of nosographic considerations in the diagnosis of schizophrenia, which must attempt to reconcile “objective knowledge of brain functioning with the subjective experiences of schizophrenia.”

The following article outlines and critiques the most prominent evidence-gathering approaches for the diagnosis of schizophrenia, before presenting an interdisciplinary framework as a promising means to bridge the division between quantitative and qualitative inquiry.



Schizophrenia
Schizophrenia is a psychiatric disorder marked by distortions in reality, changes in language patterns and behaviour, and is often accompanied by auditory or visual hallucinations, along with delusional or paranoid thinking. While the mechanisms of schizophrenia are unknown, mental health professionals, alongside neurologists and geneticists, speculate that the primary causes of schizophrenia are genetic and environmental.

Genetics
The microscopic quantitative approach seeks to define a relationship between the genomic loci and the disorder. Different experimental methods have been used, e.g. the linkage analysis (Ng et al. in 2009) and the candidate gene approach. These methods have identified specific genes linked to the illness such as DISC1. These experiments lack reliability because of the many alleles that are associated with the disease and other mental disorders. The solution was to conduct a Genome-wide association study whose findings were replicable and achieving a Genome-wide significance. However, they could not be specific to schizophrenia.

Anatomy
The macroscopic quantitative approach is to identify brain's structure abnormalities using MRI and CT scans (Whitford et al. in 2006). With these imaging methods researchers discovered that mental illness frequently correlated with ventricular enlargement and a decreased volume of grey and white matter. These anatomical variants mostly affect the patient’s language processing functions which are a symptom of many mental disorders.

However, the ventricular enlargement is usually only noticeable in the latter stages of schizophrenia and therefore of limited usefulness in early diagnosis.

Socio-Anthropological Evidence
Social sciences are needed to conceptualise and analyse "subjective" data, a central part of schizophrenia research.

Culture and Environment
Anthropology primarily provides qualitative evidence. Human beings, within their cultural context, tend to take into account various less tangible components of diagnosis.

Schizophrenia is pathoplastic in nature; hallucinations are shaped by the individual’s environmental influences. For example, ancestry-worship is a common theme in hallucinations amongst rural Africans.

Ethnographic studies have estimated that black people are six times more probable to be diagnosed as schizophrenic than average in the UK. Cognitive explanations suggest that British-African and Afro-Caribbeans express their thoughts differently from Caucasians. Psychiatric clinicians fail to identify cultural idioms and are more likely to diagnose patients from ethnic minorities with mental disorders. This elicits the question of what behaviour is considered abnormal and whether the criterion is fully dependent on the socio-cultural norms that surround the individual. Moreover, 'ethnic density’, associated with the social isolation of Afro-Caribbean communities in Western culture due to migration, has proven to be more of an influence than their socioeconomic status. Further variables to consider:
 * Differences between genders.
 * Age, especially in findings indicating men to be prone to schizophrenia earlier than women, leading to their earlier hospitalisation. The earlier diagnosis of men may also indicate a delay in diagnosing women, though they have generally shown better response towards the treatment.
 * The release of oestrogen as a possible explanation for the abovementioned, although further research will be necessary for its consideration as a form of therapy.
 * Marital status, as studies like that of Denmark and Mayhem's Case Registers appear to indicate that single young men are more likely to suffer schizophrenia. It is important to note, however, that no evidence supports marriage as a preventative method to schizophrenia.

Contemporary Psychology
As behavioural psychology has gained steady prominence through its adherence to more recognisable  scientific research and evidence gathering practices, an inverse correlation may be seen in the utilisation of subjective phenomenal experience as a nosographic tool in much of “mainstream psychology.” Increasingly, however, it is becoming evident that the complex nature of the human experience cannot be satisfactorily reduced to mere numerical data.

One criticism of neurobiological perspectives holds that they leave out the “person”. This presents a particular point of tension for those who conceptualise schizophrenia as an alteration of the experience of self or of ipseity (ipse being the Latin "self"), with ipseity defined as the experience of “basic self” through the awareness that 'I am the subject of this thought and I am the cause of the thought'.

Several alterations in ipseity may occur. One aspect is hyper-reflexivity, wherein the self-consciousness of oneself is exaggerated. In this state, previously unnoticed subconscious thoughts are experienced akin to external objects. Another facet is diminished self-affection, wherein the subject experiences decreased consciousness of themselves as the subject of their thoughts/actions. This leads to a passivity feeling described by patients as “I don't feel myself”; “I am half awake.” In schizophrenia, the above are accompanied by loss of contact with reality. Those with 'healthy' psychology view the world through articulation and context, defined as “common sense”; but for those with schizophrenia, the world appears decontextualised.

Future Research
Neglect of the first-person perspective in empirically-based approaches to the diagnosis of schizophrenia has reinvigorated interest in phenomenological diagnostic approaches, as popularised by Jaspers, Minkowski, Binswanger, Blankenburg, and Conrad. These approaches argue that neglecting the first-person perspective on alterations in ipseity—as the DSM-IV is disposed to do— "poses a serious threat for the validity of contemporary research: merely subjective phenomena are generally subjected to strict [third-person perspective] operationalizations and thereby dissected from their rich first-personal experiential qualities – however central those may be for the schizophrenic condition.”

Given that first-person experiential qualities may include qualitative data about both a patient’s attitude towards their illness as well as information about their surroundings, the interdisciplinary relevance of this line of inquiry is made readily evident.

Looking toward the future of research in schizophrenia, studies on the potentiality of phenomenologically inspired interventions and models, like those conducted by Nischk, Dölker, Rusch, and Merz, as well as those focused on person-centred psychopathology, show great promise as complementary methodologies to supplement current practices which find difficulty bridging the qualitative-quantitative evidence gap. Ultimately, more research will be necessary to determine the contribution of these efforts conclusively; however, these models presently appear to hold the most promise for expressing the validity, repeatability, and reliability of qualitative accounts of schizophrenia, such as those from introspection.