Categories, continua and the growth of psychiatric knowledge

In search of disorders: internalizing symptom networks in a large clinical sample

“…Nosologies such as the DSM and ICD characterize mental health problems as a set of discrete, 'disease-like' entities. Although this approach has undoubtedly led to advancements in our understanding of mental illhealth, limitations such as arbitrary thresholds (Bebbington, 2015;Krueger & Eaton, 2015), heterogeneity within diagnostic categories (Fried, 2015;Olbert, Gala, & Tupler, 2014) and symptom overlap across diagnostic categories (Borsboom, Cramer, Schmittmann, Epskamp, & Waldorp, 2011), have likely contributed to the problems of high comorbidity and poor reliability. These issues in turn may have impeded our attempts to uncover and understand core physiological markers (Cross-Disorder Group of the Psychiatric Genomics Consortium, 2013; Kapur, Phillips, & Insel, 2012;Kendler, 2005;Sullivan, Daly, & O'donovan, 2012) and environmental risk factors for psychopathology (Green et al, 2010), and this has led to increasing calls to move towards data-driven models that may better capture the inherent complexity of psychopathological phenotypes (Kotov, Krueger, & Watson, 2018;Van Dam et al, 2017).…”

Evaluation of the validity and utility of a transdiagnostic psychosis dimension encompassing schizophrenia and bipolar disorder

“…1 Although this dichotomy remains in DSM-5, 2 the need for a dimensional approach to classification in psychiatry, 3 and inclusion of such an approach in updated versions of DSM-5 4 and the impending ICD-11 5 continues to be debated in view of calls for research that looks across diagnostic categories 3,5 and the persistent challenge of high comorbidity rates. [3][4][5][6][7][8] In recent years, the Kraepelinian dichotomy has been challenged in light of evidence on common aetiological factors in schizophrenia and bipolar disorder. 9 Evidence has accumulated that genetic risk is partly shared between schizophrenia and bipolar disorder.…”

Letter to the Editor

“…In his interesting Editorial on Categories, continua and the growth of psychiatric knowledge, Paul Bebbington [1] slightly mis-states my earlier paper. I was not arguing that all common mental disorders can be reduced to ''overarching anxious depression domain, together with single symptom qualifiers such as obsession or panic'', for two reasons: first, the additional symptoms are in the form of a multi-symptom sets of symptoms rather than a single symptom, and second it is possible to have a common mental disorder without being at all anxious-for example, non-anxious depression.…”