Psychometric Properties of Difficulties in Emotion Regulation Scale (DERS) on Young Nigerian People

A cross-sectional survey design was adopted to validate the Difficulties in Emotion Regulation Scale (DERS) on Nigerian university undergraduates. A multistage sampling technique was used to purposively select 1338 (mean age ± SD 19.86 ± 2.95) participants made up of 512 (38.3%) male, and 826 (61.7%) were female. Participants were drawn from four selected universities in Osun state, southwestern Nigeria. Participants responded to the Difficulties in Emotion Regulation Scale, and the Structured Interview for Disorders of Extreme Stress (SIDES) Affect Dysregulation Scale. Observed internal consistency of DERS showed a Cronbach’s alpha coefficient of .90, a Spear-man-Brown coefficient of .80 and Guttman Split-Half coefficient of .80. The items that measure awareness of emotion had a weak corrected item-total correlation and did not discriminate well. A significant positive correlation was observed between DERS and SIDES, revealing a correlation coefficient validity score of (r = .622, p = .000). The DERS has acceptable psychometric properties for the Nigerian population. Observed gender-based norms were ≥113.15 and ≥114.07 for male and female respectively. DERS is found to be gender-sensitive. A re-work or expunging of the items measuring awareness to fit with the construct of emotional regulation was recommended.


Introduction
Emotion dysregulation has been defined as a multidimensional construct encompassing maladaptive responses to negative affective states. Emotion dysregulation is described by a lack of emotional awareness and understanding, no acceptance or avoidance of emotions, an unwillingness to experience negative affective states as part of achieving desired goals, difficulties controlling behaviour in the face of emotional distress, and deficits in the modulation of emotional arousal (Glenn & Klonsky, 2010;Gratz & Roemer, 2004). Emotion dysregulation has been linked to suicidal behaviour (Gomez-Exposito et al., 2016;Pisetsky, Haynos, Lavender, Crow, & Peterson, 2017). It is characterized by difficulties in emotional awareness, clarity, and acceptance and difficulties managing emotions and refraining from impulsive behaviours when in distress (Gratz & Roemer, 2004). The diagnosis and symptoms of emotional dysregulation are linked to an increased risk of future suicide attempts (Smith, Velkoff, Ribeiro, & Franklin, 2019). According to Rania, Monell, Sjolander and Bulik (2020), emotion dysregulation was linked to suicidality in Swedish participants. Suicide, according to some popular beliefs, is an attempt to flee, motivated by severe negative emotional experiences and occurring with little to no planning (e.g., Mann, Waternaux, Haas, & Malone, 1999).
Some theories which emphasize the significant emotional (e.g., fear) and physical (e.g., pain) distress associated with suicide attempts contend that people must gradually develop the capacity to commit lethal self-harm and that they are more likely to do so through deliberate attempts to die rather than frantic attempts to escape aversive states (Joiner, 2005). It might be stated that if suicide attempts are attempts to escape painful affective states, emotion dysregulation could be a credible motivating force behind this behaviour.
The Difficulties in Emotion Regulation Scale (DERS) (Gratz & Roemer, 2004) is a widely used but controversial self-report tool that assesses emotion dysregulation in a broad sense. To date, the original validation document has been cited approximately 3000 times, translated into various languages, and inspired the creation of several short forms (DERS-16; DERS-SF; DERS-18) (Bjureberg et al., 2016;Kaufman et al., 2016;Victor & Klonsky, 2016). The DERS' theoretical paradigm (Gratz & Roemer, 2004) is based on "third-wave" cognitive behavioural therapy approaches, which argue that experiential avoidance plays a fundamental role in the genesis and maintenance of most forms of emotional disturbance. Experiential avoidance is described as intolerance of (typically negative) emotional events as well as maladaptive attempts to escape them (e.g., Hayes et al., 1996). Emotion regulation abilities are considered intact in this framework when an individual can behave in a way that helps the achievement of a priori goals, especially in the face of negative affect or other intense emotional experiences.
The model upon which the DERS is based (Gratz & Roemer, 2004) proposes four broad facets of emotion regulation: 1) awareness and understanding of emotions; 2) acceptance of emotions; 3) the ability to control impulses and behave in accordance with goals in the presence of negative affect; 4) access to emotion regulation strategies that are perceived to be effective for feeling better.
This methodology has mostly been adopted in practical clinical research and therapy settings. This clinical-contextual model of emotion regulation is fundamentally different from popular emotion regulation models based on basic affective science (Aldao, 2013;Gross & Jazaieri, 2014). Affective science-based frameworks have a narrower conception of emotion regulation and place a greater emphasis on process rather than anticipated trait-level abilities (Aldao, 2013;Gross & Jazaieri, 2014;Gross, 2015).
The DERS was created to measure trait-level perceived emotion regulation capacity, as defined by the clinical-contextual paradigm of Gratz and Roemer (2004). The original development and validation study's exploratory factor analysis showed a six-or seven-component structure. The six-factor structure was deemed more interpretable and was divided into six sub-dimensions: 1) a lack of emotional Awareness (Awareness); 2) a lack of emotional clarity (clarity); 3) difficulty regulating behaviour when distressed (Impulse); 4) difficulty engaging in goal-directed cognition and behaviour when distressed (Goals); 5) unwillingness to accept certain emotional responses (Non-acceptance); 6) a lack of access to strategies for feeling better. Several later factor analytic investigations back up the initial six-factor model's fit across a range of populations, including undergraduate students (Perez et al., 2012) and teenagers (Weinberg & Klonsky, 2009;Neumann et al., 2010). Despite the wide use and acceptance of this scale, it is yet to receive adequate research attention in Nigeria.
The DERS has not been validated on any Nigerian population to our knowledge. The undergraduates from Nigerian universities were chosen not because they had the greatest levels of emotion-related illnesses. Emotion dysregulation, on the other hand, is a substantial health concern for roughly 5% to 10% of teenagers and young people in the general population, according to figures in the literature. Depression is now again an increasing concern among Nigeria's student population. Depressive symptoms have been linked to a disruption in nega-

Study setting
This study was carried out in four different universities in Osun State. These included one Public State-owned University, two Private Faith-based Universities, and one private non-faith-based University.
One thousand three hundred thirty-eight undergraduates were drawn from four universities in Osun state, southwestern Nigeria. The eligibility criteria included registered undergraduate students who were currently on full-time study bases at the time of data collection and were found within the selected universities campuses. Also, only those who consented to be part of the study were included.

Statistical Analysis
Descriptive statistics, including mean and standard deviation, were used to determine demographic characteristics of the participants.

Results
The demographic distribution of respondents by sex indicated that 512 (   Disorders of Extreme Stress (SIDES) Affect Dysregulation Scale (Brown et al., 2012) was .622, p = .000. This result showed that DERS is valid for the Nigerian population.

Norms for DERS
The 95% confidence interval (CI) was used to determine the cutoff points for DERS. The derived CI based on a sample of 481 male participants was between a range of 92.7 and 96.0. On the other hand, the derived CI for females based on 780 samples was between a range of 90.6 and 93.7. The mean plus one standard deviation of ≥113.15 and ≥114.07 was considered the cutoff points (norm) for the male and female samples. Scores above the norm implied emotion dysregulation. This is summarized in Table 3.
As summarized in Table 4, the score of the mean plus 1 standard deviation of each of the subscales of the DERS was used to determine the cutoff for the subscales.

Discussion
The focus of this study is to obtain a psychometric property for the difficulties in emotion regulation scale (DERS) for the Nigerian adolescent population. Consistent with previous findings (Gratz & Tull, 2010;Nordgren et al., 2019;, the DERS on Nigerian samples has excellent internal consistency, showing a Cronbach's alpha of .90. This, by implication, shows a good inter-relatedness of the items of the DERS, unidimensionality and homogeneity of the construct (Cortina, 1993;Bland & Altman, 1997) among the Nigerian population. The alpha score is also not too high to render some items redundant as the alpha values did not exceed the maximum value of .90 (Streiner, 2003;DeVellis, 2003).
Our study's high Cronbach's alpha score shows that DERS has a strong internal  (Bland & Altman, 1997;Streiner, 2003) for all items in the subscales except for lack of emotional clarity which reported (α = .54). This indication showed that the clarity items should be used with caution among Nigerian samples (Deepa-Enlighten, 2017) or adapted to suit the population. The explanation for this could be due to social-cultural differences.
Again we found that the items that measure awareness reported weak corrected  (Giromini et al., 2012), chronic pain patients (Kökönyei et al., 2014), adults with severe mental illness (Fowler et al., 2014), and adult outpatients receiving Dialectical Behavior Therapy (DBT) (Fowler et al., 2014), have found poor fit for a six-factor solution in a variety of populations (Osborne et al., 2017). In general, these studies suggest that a revised five-factor model with the Awareness subscale and items removed provides a better match to the data (Bardeen et al., 2012;Fowler et al., 2014;Osborne et al., 2017).
Finally, the obtained norm for the Nigerian sample is a novel addition to the scale as the developer, and previous users of DERS did not indicate a norm for the scale. The norm derived from this study also established the gender sensitivity of the scale. According to Goubet and Chrysikou (2019), the effect of gender on emotion regulation has not been given adequate study. Gender differences in emotion regulation may explain gender differences in clinical presentation in some psychopathologies (Hyde et al., 2008;Nolen-Hoeksema, 2012). Thus establishing norms in measures such as DERS is essential for clinical practice in addition to its usefulness in research.

Conclusion and Recommendations
Based on the findings, the 36-item DERS showed good internal reliability and a valid measure of emotional regulation. This analysis indicates that DERS is reli-Psychology able and valid for the Nigerian population. Also, the items that measure awareness of emotion had a weak corrected item-total correlation. However, the items that measure the Awareness dimension did not discriminate well and thus were ambiguous and confusing to participants. Hence authors recommend that the awareness subscale be re-worked to fit with the construct of emotional regulation or expunged altogether from the scale. Norms for the composite and dimensions of DERS were established, and DERS is observed to be gender-sensitive based on this.
The DERS is recommended for use in clinical settings, especially among people with emotional disorders such as anxiety disorders, mood disorders, obsessivecompulsive disorders, psychotic disorders, eating disorders, conduct disorders and trauma-related disorders to assess emotion regulation. Also, the associations between emotion regulation, impulsivity and suicidal behaviours can be properly assessed using the DERS. Using the DERS could help make the proper diagnosis and the correct treatment procedure. Also, researchers' DERS can be used in research settings to provide information on the factors of Emotion Dysregulation across people in the general public and clinical settings.

Ethical Approval
Human subjects were used in this work; hence research ethics for human subjects were followed in accordance with the Helsinki Declaration.

Informed Consent
Prior to administering the instruments, respondents' consent was requested.
Respondents were permitted to quit at any point throughout the survey because participation was optional and confidentiality was guaranteed.