Foundations of idiographic methods in psychology and applications for psychotherapy

Abstract

Researchers have long called for greater recognition and use of longitudinal, individuallevel research in the study of psychopathology and psychotherapy. Much of our current research attempts to indirectly investigate individual-level, or idiographic, psychological processes via group-based, or nomothetic, designs. However, results from nomothetic research do not necessarily translate to the individual-level. In this review, we discuss how idiographic analyses can be integrated into psychotherapy and psychotherapy research. We examine and review key statistical methods for conducting idiographic analyses. These methods include factor-based and vector autoregressive approaches using longitudinal data. The theoretical framework behind each approach is reviewed and critically evaluated. Empirical examples of each approach are discussed, with the aim of helping interested readers consider how they may use idiographic methods to analyze longitudinal data and psychological processes. Finally, we conclude by citing key limitations of the idiographic approach, calling for greater development of these analyses to ease their successful integration into clinical settings.

An Examination of Idiographic Networks of Posttraumatic Stress Disorder Symptoms

“…Instead, describing these individual‐level processes requires estimating idiographic symptom networks. We believe that this distinction is critical as our field moves toward adopting a more personalized model of psychological dysfunction and empirically supported care (Fisher, 2015; Fisher & Boswell, 2016; Piccirillo & Rodebaugh, 2019). The present study estimated contemporaneous and temporal networks for 20 participants with current PTSD.…”

“…Finally, these results also highlight the importance and utility of estimating idiographic symptom networks. As noted, although cross‐sectional nomothetic networks provide robust descriptions of symptom importance and symptom associations that occur at the group‐level, these fall short of describing the organization or presentation of symptoms within a single individual as they occur over time (Fisher et al., 2017, 2018; Piccirillo & Rodebaugh, 2019). For example, although negative trauma‐related emotions is a symptom that has exhibited high centrality in cross‐sectional networks in the literature (Armour et al., 2017; Mitchell et al., 2017), the symptom was among the least central symptoms in Bob's contemporaneous network.…”

“…The past decade has seen several efforts to tailor psychological interventions to the needs and characteristics of each individual patient (Fisher & Boswell, 2016; Piccirillo & Rodebaugh, 2019). The present results show the potential utility of combining idiographic approaches and network theory to move the field closer to this goal.…”

“…That is, the variance and covariance of PTSD symptoms in cross‐sectional group data are not equivalent to the variance and covariance of these same symptoms for a single individual over time. Further, although some past research has estimated multilevel networks from longitudinal data as a way to address the limitations of cross‐sectional PTSD networks (Greene et al., 2018; Hoffart et al., 2019), these studies still fall short of describing the person‐specific nature of these intraindividual processes due to violations of the underlying homogeneity assumptions of these models (Fisher, Medaglia, & Jeronimus, 2018; Molenaar, 2005; Piccirillo & Rodebaugh, 2019). Thus, it follows that insights about the nature of PTSD gleaned from nomothetic networks are unlikely to adequately inform researchers and clinicians about processes occurring at the individual level.…”

“…Over the past decade, researchers have increasingly pushed for a renewed emphasis on idiographic methods, as these might be useful for tailoring psychological interventions to the experiences of individual patients (Fisher, 2015; Fisher & Boswell, 2016; Piccirillo & Rodebaugh, 2019). These authors have argued that idiographic methods will be critical to the creation of precision mental health systems and the personalization of assessment and intervention (Fisher et al., 2019; National Institutes of Health, 2017).…”