The Nighttime Fears Scale: Development and psychometric evidence of a standardized self-report scale to assess nighttime fears in children

Highlights

• The Nighttime Fears Scale is a new self-report measure for assessing children’s nighttime fears.

• Exploratory and confirmatory factor analyses supported a four-factor structure.

• The scale consists of 21 items measuring potentially fear-provoking stimuli at nighttime.

• Adequate internal consistency, test-retest reliability and validity were found.

• This study provided initial support for the use of a promising standardized tool.

Abstract

Nighttime fears are highly prevalent in children and are linked to children’s distress and internalizing problems, especially childhood anxiety. Although its assessment may be critical, there is a lack of available standardized self-reports. This study aimed to describe the development and psychometric evaluation of the Nighttime Fears Scale (NFS), a new standardized self-report for assessing nighttime fears in school-aged children. The construction of the scale was based on prior relevant research and involvement of researchers and clinicians, experts in childhood anxiety, and fears. A total of 794 Spanish-speaking children (51.1 % girls) aged 8–12 years completed the NFS along with measures of anxiety, sleep problems, internalizing and externalizing problems, and positive behaviors. Exploratory and confirmatory factor analyses supported a four-factor structure of the NFS, consisting of 21 items measuring a range of potentially fear-provoking stimuli at nighttime. Strong internal consistency (alphas ranging from .87 to .94), adequate test-retest reliability, and evidence of convergent, divergent and incremental validity was found. This study provides initial support for the use of the NFS by clinicians and researchers, suggesting that it is a promising tool for a rapid and easily-administered assessment to identify the presence and intensity levels of a set of common children’s nighttime fears.

Introduction

Specific fears are considered normative and highly prevalent in children, with rates above 86 % of children presenting at least one fear being reported, while their intensity may differentiate normative from clinical manifestations (Laporte et al., 2017). Normative fears tend to be transitory, but if they occur intensively, problematic symptoms can arise, which can evolve into anxiety disorders if they persist (Beesdo-Baum & Knappe, 2012). The presence of nighttime fears among schoolchildren has been shown to be quite common, with rates around 70 % (Gordon, King, Gullone, Muris, & Ollendick, 2007; Muris, Merckelbach, Ollendick, King, & Bogie, 2001). In most children, they are a developmentally normative occurrence, and are transient and non-problematic. Some children may also experience these fears intensely and persistently, generating considerable child and family distress and interference (Gordon & King, 2002; King, Ollendick, & Tonge, 1997).

Despite the considerable frequency of nighttime fears (e.g., fear of the dark, imaginary stimuli such as monsters or ghosts; Laporte et al., 2017; Meltzer et al., 2009), the available literature continues to be limited but has been growing over the last decades. Existing research has proposed that nighttime fears are heterogeneous and can include fear of a variety of stimuli (e.g., darkness, noises, being alone, imaginary creatures, intruders; King et al., 1997). Moreover, relevant studies addressing the frequency and content of nighttime fears in community samples of schoolchildren have reported interesting data. For instance, the study by Muris et al. (2001) found in 4- to 12-year-old children that fear of intruders (e.g., kidnappers, burglars) was the most common nighttime fear, followed by fear of imaginary creatures (e.g., monsters, ghosts), frightening dreams, environmental threats (e.g., thunderstorms, the dark), animals (e.g., spiders), and frightening thoughts (e.g, worry about parents dying or about personal health). These authors also found that nighttime fears were more prevalent in the age range of 7–12 years than in younger children, and similar in girls snd boys. Furthermore, Gordon et al. (2007) showed that children aged 8–12 ha d significantly more and more severe nighttime fears than adolescents aged 13–16 years, with girls reporting higher nighttime fears than boys. These authors classified nighttime fears similarly to Muris et al. (2001) and found that the most frequent nighttime fears were related to environmental threats (indoor or outdoor noises), personal security (intruders), frightening dreams (fear of bad dreams), darkness (fear of the dark), and imaginary creatures (e.g., ghosts, witches, skeletons).

Fear is intended to be an adaptative and integrated behavioral, physiological, and cognitive-emotional response to danger. However, inappropriate or excessive fear can be linked to psychiatric disorders, including anxiety disorders (e.g., phobias; Fanselow & Pennington, 2018; Garcia, 2017). In this regard, specific fears have been related to internalizing problems (i.e., symptoms of depression and anxiety) and anxiety disorders such as separation anxiety disorder, specific phobia, and generalized anxiety disorder (Muris, Mannens, Peters, & Meesters, 2017; Muris, Merckelbach, Mayer, & Prins, 2000). Similarly, nighttime fears have been related to the presence of moderate levels of anxiety, but may also be related to the above-mentioned anxiety disorders in a small percentage of children (Gordon et al., 2007; Muris et al., 2001). Symptoms of such anxiety disorders and overall anxiety are highly prevalent in school-age children within the 8–12 age range. These are, in turn, associated with considerable risk of homotypic and heterotypic comorbidity (e.g., depression), significant impairment, and a high symptom persistence (Canals, Voltas, Hernández-Martínez, Cosi, & Arija, 2019; Romero et al., 2010). Moreover, children’s nighttime fears have been related to sleep problems (e.g., difficulties in sleeping alone, resistance to going to bed, sleeping less), internalizing and externalizing symptoms, and it is argued that frequent nighttime fears may be a maintenance or risk factor of sleep-disruptive practices (El Rafihi-Ferreira, Lewis, McFayden, & Ollendick, 2019).

Therefore, considering that nighttime fears can have negative effects on children's lives warrants the need for their accurate assessment and early detection. In addition, considering the heterogeneous nature of nighttime fears and that they occur mostly as part of normal child development and are not problematic (Gordon & King, 2002; Muris et al., 2001), having adequate and specific assessment tools would be especially interesting to tap them efficiently and to deepen their study and understanding within child development. However, although progress has been made in the development of effective treatments for nighttime fears in recent years (e.g., Lewis, Amatya, Coffman, & Ollendick, 2015; Simon, Driessen, Lambert, & Muris, 2020), the literature shows the need to develop more specific assessment instruments. Self-report instruments are considered an important assessment method because internalizing experiences, such as fears and fear-related anxiety, are not always observable and are only accessible through the child's introspection (Muris, 2019). Previous relevant studies tended to use only children’s interviews to assess nighttime fears and not self-report questionnaires. This has been noted as a limitation and it has been argued that interviews may involve limitations (e.g., interviewer interpretation bias), whereas standardized self-report questionnaires can be also useful in identifying specific fear-producing stimuli through predetermined fear categories or structures (Gordon et al., 2007; Muris et al., 2001). Moreover, self-report questionnaires are among the most commonly used assessment methods in clinical psychology. It allows a quick assessment with low financial and time cost, it offers information given by the respondent, it can be applied in clinical and epidemiological studies, and within a more comprehensive assessment (Demetriou, Ozer, & Essau, 2015).

Following Kushnir, Gothelf, and Sadeh (2015), prior research focused on school-aged children’s common fears has relied on standardized self-report questionnaires composed of lists of potentially fear-provoking situations or stimuli. For instance, widely used for the measure fearfulness, including a variety of specific fears types (e.g., fears of animals, heights, danger, death, unknown things, social or medical situations), are the revised version of the Fear Survey Schedule for Children (FSSC-R; Ollendick, 1983) or the Koala Fear Questionnaire (KFQ; Muris et al., 2003). However, they are not designed to measure fears only experienced at nighttime, and few items refer to stimuli that could be considered to specifically occur at night, when the children score it (e.g., darkness-related fears, scary dreams). In this regard, to the best of our knowledge, there is currently a lack of self-report questionnaires focused on specifically assessing nighttime fears. Some recent studies have used self-reports to evaluate only a specific nighttime-related fear (e.g., the dark), but created only for the study purposes (e.g., Simon et al., 2020). Authors such as Mooney (1985) and Mooney, Graziano, and Katz (1985) tried to advance in the study of nighttime fears and used original checklists for its research (i.e., including categories such as “security-separation or loss of others,” “security-personal life, loss, and safety,” “inherent characteristics,” “dark,” “dreams,” and “imaginal-numinous”). Nevertheless, this approach was not further developed in terms of analyzing psychometric properties and providing a reliable and valid self-report instrument to be widely used. Although these early contributions were important in this field, they have been serving mainly to guide the classifications of nighttime fears in subsequent research (e.g., Gordon et al., 2007).

Therefore, it is still necessary to advance in the development of a self-report questionnaire with sound psychometric properties to specifically assess children's nighttime fears and to fill in this gap. Thus, given the paucity of specific self-reports available in this field, this study aimed to describe the development and psychometric properties of a new measure, the Nighttime Fears Scale (NFS). The NFS was intended to offer advantages such as providing an innovative standardized self-reporting instrument that (a) is brief, easily administered, reliable, and valid, allowing researchers and clinicians to quickly identify the presence and intensity levels of a range of common nighttime fears from the children’s perspective, b) can be useful mainly to improve the study and understanding of normative nighttime fears in childhood, but also the early detection of problematic fears in large epidemiological investigations, and c) can be used in conjunction with other strategies (e.g., interview) in a more in-depth assessment throughout the clinical or research process. The current research consists of two steps. In Step 1, we developed a new scale to assess nighttime fears in children. In Step 2, we examined the psychometric properties of the final version of this new tool in a sample of Spanish-speaking children aged 8–12 years, taking into account prior findings suggesting a greater frequency and severity of nighttime fears in this age group (Gordon et al., 2007; Muris et al., 2001), as well as a considerable presence of emotional problems (e.g., Canals et al., 2019; Romero et al., 2010).