The structure of psychopathology and the association of environmental adversity

Abstract

Contemporary research has shown that psychiatric disorders are neither precise nor empirically valid as they contain heterogeneity within disorders, and comorbidity across diagnostic categories (Wolfe et al, 1988; Watson 2005; Markon, 2010; Kotov etal., 2010,2011). Recent research has utilised factor analysis to elucidate the fact that DSM/ICD diagnoses cluster together in superordinate global dimensions, i.e. Externalising, Internalising and Psychosis. This has highlighted the fact that the global dimensions can explain observed patterns of comorbidity and demonstrate broadly distinct spectra of psychopathology (Keyes et al, 2012). The current research of DSM Axis I disorders has identified three global dimensions which are a more natural yet empirical classification of mental illness (Markon, 2010). By employing a person centred approach such as latent profile analysis (LPA) it was possible to extract homogeneous groups of individuals who had similar levels of Internalising, Externalising and Psychosis. By using the latent profiles in the NCS and APMS datasets it was possible to assess the associations between the person-centred latent profiles and environmental adversity (EA) variables. The findings indicated that EA such as socio-demographics, adverse parenting, stressful life events and traumatic experiences are significantly predictive of the psychopathological profiles. Furthermore, latent class analysis of traumatic experience demonstrated particularly high odds ratios that were predictive of the more severe and milder psychopathological dispositions. The findings suggest that exposure to multiple traumata creates an epigenetic basis and progression to Externalising, Internalising and Psychosis dispositions. In summary, psychiatric diagnoses are more accurately explained by the global dimensions of Externalising, Internalising and Psychosis. EA variables are predictive of psychopathology and would appear to be causal in relation to the aetiology of psychiatric disorders or emotional imbalances. It may be advisable for therapists and psychiatrists to assess the clients’ life history for epigenetic effects from EA such as traumatic experiences and to formulate treatment plans that accordingly explore these experiences.

Date of Award	Jul 2015
Original language	English
Supervisor	Mark Shevlin (Supervisor) & Jamie Murphy (Supervisor)