Distribution of psychological distress is stable in recent decades and follows an exponential pattern in the US population

Abstract

The prevalence of psychological distress is fairly stable in industrialised countries in recent decades, but the reasons for this stability remain unknown. To investigate the mechanisms underlying stability of psychological distress in the general population of the United States, we analysed the mathematical patterns of the distribution of psychological distress in recent decades. The present study utilised the Kessler psychological distress scale (K6) data from the 1997‒2017 United States National Health Interview Survey. We used overlap coefficients and graphical analysis to investigate the stability and mathematical patterns of the K6 distribution. Overlap coefficients and graphical analysis demonstrated that the distribution of K6 total scores was stable in the United States over the past two decades. Furthermore, the distributions of K6 total scores exhibited an exponential pattern, with the exception of the lower end of the distribution. These findings suggest that the lack of change in the prevalence of psychological distress over several decades is due to the stability of psychological distress distribution itself. Furthermore, the stability of the distribution of psychological distress over time may be linked to the exponential pattern of psychological distress distribution.

Psychological distress associated with COVID-19 quarantine: Latent profile analysis, outcome prediction and mediation analysis

“…In the face of threats, stress promotes environmental adaptation through an orchestrated neuro-hormonal and sympathetic response ( De Kloet et al., 2005 ; Ellis and Del Giudice, 2019 ). Psychological distress exists on a continuum in the population, from a transient and adaptive response to stressors, to those at the extreme end which may be at higher risk for mental disorders ( Kessler et al., 2010 ; Tomitaka et al., 2019 ). Intense psychological distress is a hallmark of mental disorders associated with poorer health outcomes and increased mortality risk ( Barry et al., 2020 ; Phillips, 2009 ).…”

“…and personal resources (i.e., personality, income, perceived control, etc.) modulate individuals´ level of psychological distress ( Byles et al., 2014 ; Drapeau et al., 2012 ; Tomitaka et al., 2019 ). Considering such factors from a diathesis-stress perspective, individuals’ response to stressors may be mediated by perceived threat intensity and the ability to cope with such external demands ( Beck and Dozois, 2011 ; Lazarus, 1966 ).…”

Patterns of item score and total score distributions on depression rating scales in the general population: evidence and mechanisms

“…Recent analyses of large-scale data have revealed that total scores in self-rated depression scales exhibit a common distribution in the general population. For example, as shown in Figures 1 A, 1B, and 1C, right-skewed distributions of total scores are similarly observed in the CES-D data from the Japanese Active Survey of Health and Welfare [ 12 ], the PHQ-9 data from the National Health and Nutrition Examination Survey [ 11 ], and the K6 data from the National Health Interview Survey in the United States (US) [ 14 ]. Generally, a score of ≧ 16 on the CES-D, a score of ≧ 10 on the PHQ-9, and a score of ≧ 13 on the K6 are defined as the cut-point for clinical depression.…”

“…Furthermore, responses to all depressive symptom items show a proportional relationship between response options, except for the lower end option [ 10 ]. These findings have been confirmed repeatedly by analyzing large-scale data collected from dozens of nationally representative surveys in the US, EU, and Japan [ 12 , 13 , 14 , 15 ].…”

“…The process of screening excluded 86 articles because they were not related to mathematical patterns of item score and total score distributions on depression rating scales. The remained 16 articles were considered relevant to this current review [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. The ethics committees of Kyoto University Graduate School of Medicine and Panasonic Health Center do not consider literature analysis to be human research and, thus, the need for ethical approval was waived.…”