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The Intolerance of Uncertainty Model (IUM) of Generalized Anxiety Disorder (GAD) attributes a key role to Intolerance of Uncertainty (IU), and additional roles to Positive Beliefs about Worry (PBW), Negative Problem Orientation (NPO), and Cognitive Avoidance (CA), in the development and maintenance of worry, the core feature of GAD. Despite the role of the IUM components in worry and GAD has been considerably demonstrated, to date no studies have explicitly assessed whether and how PBW, NPO, and CA might turn IU into worry and somatic anxiety. The current studies sought to re-examine the IUM by assessing the relationships between the model’s components on two different non-clinical samples made up of UK and Italian undergraduate students. One-hundred and seventy UK undergraduates and 488 Italian undergraduates completed measures assessing IU, worry, somatic anxiety, depression, and refined measures of PBW, NPO, and CA. In each sample, two mediation models were conducted in order to test whether PBW, NPO, and CA differentially mediate the path from IU to worry and the path from IU to somatic anxiety. Secondly, it was tested whether IU also moderates the mediations. Main findings showed that, in the UK sample, only NPO mediated the path from IU to worry; as far as concern the path to anxiety, none of the putative mediators was significant. Differently, in the Italian sample PBW and NPO were mediators in the path from IU to worry, whereas only CA played a mediational role in the path from IU to somatic anxiety. Lastly, IU was observed to moderate only the association between NPO and worry, and only in the Italian sample. Some important cross-cultural, conceptual, and methodological issues raised from main results are discussed.
Intolerance of Uncertainty (IU) can be defined as the “individual’s dispositional incapacity to endure the aversive response triggered by the perceived absence of salient, key, or sufficient information, and sustained by the associated perception of uncertainty” (
A robust body of research bolstered the evidence of IU, the model’s main feature, as a cognitive vulnerability factor for worry, as well as a maintaining factor for GAD (e.g.,
Despite the role of all components in worry and GAD has been considerably demonstrated (e.g.,
In the last decade a fast growing interest in the role of IU as a shared vulnerability factor for emotional disorders (e.g.,
Despite such a shift in the conceptualization of IU (from disorder-specific variable to transdiagnostic factor), we believe that gaining a better understanding of the mechanisms through which IU operates within specific conditions, leading to specific kinds of phenomenology, might help clarifying how processes may be specifically enacted in a way close to the expression of symptoms. Therefore, the main aim of the present study was to re-examine the original IUM model and, taking into account the previously mentioned evidence supporting the dominance and precedence of IU on worry/GAD (please refer to
First, research on analog samples could be appropriate when advancing theories and models aimed at understanding clinical phenomena, also because the phenotypic heterogeneity characterizing clinical populations, as well as the existence of comorbidity or treatment confounds, could represent a possible obstacle to the investigation of the etiology of psychological disorders (e.g.,
Second, we sought to preliminary investigate whether such a refined IUM model could be applicable across cultures. Notably, evaluating the existence of cross-cultural differences when dealing with depression and anxiety is generally encouraged (e.g.,
In light of the above-mentioned issues, we re-examined the Laval model for GAD by conducting two studies testing two different mediation models in two different undergraduate samples (UK and Italian). In particular, we aimed at testing whether PBW, NPO, and CA differentially mediate the path from IU to worry and the path from IU to somatic anxiety. We expected that:
PBW, in light of their content specificity to worry (
NPO would mediate the paths from IU to both worry and somatic anxiety. Indeed, findings by
In light of evidence supporting that higher IU leads to higher levels of worry (e.g.,
Lastly, since no previous studies comparing the IUM components across UK and Italian undergraduate samples were conducted, we decided to exploratory investigate the presence of any similarities and differences between groups without advancing specific hypotheses. However, keeping in mind that the British and the Italian cultures are claimed to differ in terms of “uncertainty avoidance” (
One hundred and seventy (86.5% females) UK undergraduate students entered Study 1. Participants were all students attending their 1st year aged between 18 and 30 years (
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Double data entry was performed to ensure data reliability. All statistical analyses were performed using the software Statistical Package for the Social Sciences (SPSS) version 22.
Prior to analyses, missing data (<1%) in questionnaires were replaced with the participant’s mean score on the respective measure. All measures were then screened for univariate and multivariate normality, and distributions of all continuous data were checked. Distributions on measures were considered normal according to figures of skew and kurtosis. Generally, scores were normally distributed with all items demonstrating acceptable levels of skewness and kurtosis (≤|1| ). The DASS-21 Anxiety and Depression scales evidenced significant skewness and were subsequently transformed to a normal distribution by applying a log10 transformation. Internal consistency of all measures was assessed by computing Cronbach alphas (α) coefficients.
Intercorrelations among all study measures were performed by calculating Pearson’s
Furthermore, since PROCESS allows testing conditional indirect effects of an independent variable, which means assessing an independent variable’s effect on the dependent variable through mediators, depending on a moderator (i.e., moderated mediation) (
Mean scores (SDs) obtained by participants (not transformed scores) on all the study’s measures are reported in
Mean, standard deviations and Cronbach alphas observed in the UK undergraduate sample in all study measures.
Cronbach alpha | |||
---|---|---|---|
IUS-12 | 30.38 | 10.47 | 0.93 |
WW-III | 91.36 | 22.97 | 0.94 |
NPOQ | 30.99 | 12.50 | 0.96 |
R-CAQ | 85.77 | 3.66 | 0.94 |
PSWQ | 52.49 | 14.94 | 0.78 |
DASS-21 Anxiety | 3.89 | 4.04 | 0.85 |
DASS-21 Depression | 4.66 | 4.25 | 0.89 |
Correlations (Pearson rs) between the scores on all measures observed in the UK undergraduate sample.
WW-III | NPOQ | R-CAQ | PSWQ | DASS-21 Anxiety | DASS-21 Depression | |
---|---|---|---|---|---|---|
IUS-12 | 0.19** | 0.70** | 0.47** | 0.68** | 0.53** | 0.50** |
WW-III | 0.20** | 0.26** | 0.28** | 0.19** | 0.23** | |
NPOQ | 0.49** | 0.68** | 0.53** | 0.58** | ||
R-CAQ | 0.36** | 0.40** | 0.40** | |||
PSWQ | 0.49** | 0.48** | ||||
DASS-21 Anxiety | 0.59** |
The first mediation analysis examined the indirect effects of IUS-12 scores on PSWQ scores through WW-III, NPOQ, and R-CAQ, controlling for DASS-21 Depression. Unstandardized regression coefficients of the direct effects are reported in
The overall model was significant (
Specific and total indirect effects of IU on worry and somatic anxiety through PBW, NPO, and CA controlling depression in the UK undergraduate sample.
Bootstrapped 99% CIs | |||||
---|---|---|---|---|---|
Dependent variable | Mediators | Point estimate | Lower | Upper | |
PSWQ | WW-III | 0.0029 | 0.0112 | -0.0196 | 0.0626 |
NPOQ | 0.3152 | 0.0810 | 0.1220 | 0.5729 | |
R-CAQ | -0.0208 | 0.0339 | -0.1252 | 0.0702 | |
Total | 0.2972 | 0.0810 | 0.1138 | 0.5287 | |
DASS-21-Anxiety | WW-III | 0.0000 | 0.0002 | -0.0005 | 0.0011 |
NPOQ | 0.0019 | 0.0018 | -0.0027 | 0.0068 | |
R-CAQ | 0.0010 | 0.0010 | -0.0016 | 0.0041 | |
Total | 0.0029 | 0.0021 | -0.0020 | 0.0089 |
Results from the first mediation model suggest that only NPO has a mediational role in the path from IU and worry in UK undergraduates. This finding provides only partial support to the original hypotheses, since neither PBW nor CA emerged to mediate the relationship between IU and worry. Furthermore, results from the second mediation model highlighted that the path from IU to somatic anxiety was not mediated by any of the three hypothesized mediators. Despite not confirming our hypotheses, such a result could be reasonable considering that the Laval model of GAD aimed to conceptualized PBW, NPO, and CA as specifically related to worry severity than to somatic anxiety symptom severity. Lastly, IU did not emerge to influence the mediational path to worry through NPO, thus it was not a moderator.
Four hundred and eighty-eight Italian undergraduate students (61.7% females), aged between 19 and 27 years (
The Italian translations of the above-described (please refer to Study 1) IUS-12, WW-III, NPOQ, and R-CAQ were administered. Since no validated version of those instruments was available at the time the study was conducted, the standard forward-back translation procedure was performed (e.g.,
Mean, standard deviations and Cronbach alphas observed in the Italian undergraduate sample in all study measures.
Cronbach’s alpha | |||
---|---|---|---|
IUS-12 | 24.63 | 6.44 | 0.81 |
WW-III | 93.39 | 25.21 | 0.94 |
NPOQ | 24.50 | 8.93 | 0.92 |
R-CAQ | 71.61 | 18.78 | 0.93 |
PSWQ | 43.83 | 11.27 | 0.68 |
BAI | 9.15 | 8.48 | 0.90 |
BDI-II | 9.65 | 8.23 | 0.90 |
Furthermore, the validated Italian version of the PSWQ (
Lastly, instead of the DASS-21, the Beck Anxiety Inventory (
The
The
The same procedure and data analytic strategy described in Study 1 were applied in Study 2. Also in Study 2 several variables, namely NPOQ, R-CAQ, BAI, and BDI-II evidenced significant skewness and were subsequently transformed to a normal distribution by applying a log10 transformation.
Furthermore, similar to Study 1, the employed depression measure (BDI-II) showed positive correlations with all the other variables (please refer to
Correlations (Pearson rs) between the scores on all measures observed in the Italian undergraduate sample.
WW-III | NPOQ | R-CAQ | PSWQ | BAI | BDI-II | |
---|---|---|---|---|---|---|
IUS-12 | 0.34** | 0.57** | 0.35** | 0.51** | 0.40** | 0.41** |
WW-III | 0.25** | 0.29** | 0.38** | 0.23** | 0.23** | |
NPOQ | 0.43** | 0.56** | 0.46** | 0.58** | ||
R-CAQ | 0.35** | 0.43** | 0.42** | |||
PSWQ | 0.53** | 0.49** | ||||
BAI | 0.57** |
Means (SDs) and Cronbach alphas obtained on all the study measures (not transformed scores) are displayed in
The first mediation analysis examined the indirect effects of IUS-12 scores on PSWQ scores through WW-III, NPOQ, and R-CAQ scores, controlling for BDI-II scores. Unstandardized regression coefficients of the direct effects are reported in
Specific and total indirect effects of IU on worry and somatic anxiety through PBW, NPO, and CA controlling depression in the Italian undergraduate sample.
Bootstrapped 99% CIs | |||||
---|---|---|---|---|---|
Dependent variable | Mediators | Point estimate | Lower | Upper | |
PSWQ | WW-III | 0.0989 | 0.0462 | 0.1888 | 0.4313 |
NPOQ | 0.1909 | 0.0377 | 0.0990 | 0.2958 | |
R-CAQ | 0.0077 | 0.0157 | -0.0298 | 0.0555 | |
Total | 0.2975 | 0.0462 | 0.1888 | 0.4313 | |
BAI | WW-III | 0.0005 | 0.0007 | -0.0013 | 0.0024 |
NPOQ | 0.0019 | 0.0012 | -0.0011 | 0.0051 | |
R-CAQ | 0.0022 | 0.0007 | 0.0007 | 0.0045 | |
Total | 0.0046 | 0.0015 | 0.0009 | 0.0086 |
The second mediation analysis examined the indirect effects of IUS-12 scores on BAI through WW-III, NPOQ, and R-CAQ scores controlling for BDI-II scores. Unstandardized regression coefficients of the direct effects are reported in
Findings emerged from the two mediation models were partially in line with our hypotheses. First, both PBW and NPO, but not CA, were significant mediators in the path from IU and worry; second, only CA (but not NPO) played a mediational role in the path from IU and somatic anxiety. Lastly, IU moderated only the association between NPO and worry: The higher were IU levels, the larger was the mediational effect of NPO.
The IUM for GAD identified four main components associated with the development and maintenance of worry: IU, PBW, NPO, and CA (
Our first hypothesis stated that PBW would have mediated the relationship between IU and worry but not the relationship between IU and somatic anxiety. As far as concern the path to worry, such an expectation was only partially sustained: Indeed, PBW emerged as a mediator only in the Italian sample. The different mediational patterns observed across samples is no better explained by a different degree of reliance in such beliefs across samples, since groups scored similarly on the WW-III (
The second hypothesis of the current study was that NPO and CA would have been mediators in the paths from IU to both worry and somatic anxiety. As far as concern NPO, it emerged to play a mediational role in the path from IU to worry both in Studies 1 and 2 thus demonstrating its involvement across cultures. On the other hand, NPO did not emerge to play any mediational role in the path from IU to somatic anxiety, which is in contrast with previous evidence highlighting this cognitive variable to be relevant also to somatic anxiety (e.g.,
To summarize, the current re-examination of the IUM for GAD showed that the original conceptualization of the model, claiming that IU contributes to worry and anxiety through PBW, NPO, and CA is substantially supported but only in the Italian undergraduate sample, whereas findings emerged from the UK one are controversial. The discrepancies characterizing main results obtained in the two samples further strengthen the recommendation of performing cross-cultural studies in the field of anxiety, since it looks like that people from different cultures might actually interpret and express their symptoms in a different way, and cross-cultural research should help in understanding why and how (
Several further limitations characterizing the present study should be taken into account. The sample sizes employed, despite not extremely small, do not allow to generalize emerged results. A further obstacle to the generalization of results is represented by the cross-sectional nature of the current data. Indeed, we tested a conceptually (and partially empirically demonstrated) plausible model, but many cross-sectional models have equally plausible alternatives; furthermore, a number of biases characterizing the tests of mediation when using cross-sectional data have been highlighted (e.g.,
Keeping in mind the above-mentioned limits, overall present results provide support to the current refinement of the original Laval model, where the IUM components are better conceptually integrated. Differential cross-cultural IU mechanisms, as well as potentially different worry domains across cultures, might have contributed to observed findings and deserve further investigation. Clinically, the findings tentatively suggest that understanding how people of different cultures understand and express uncertainty and IU may be central in our ability to target it effectively in therapy.
GB: Performed literature review, statistical analyses and wrote the manuscript. MG: Performed literature review and contributed in writing up the manuscript. EC, NB, and RP: Performed data collection, data entry, and support to data analyses. MF: Designed and supervised the entire project.
MF declares he has received training honoraria and book royalties on closely related topics. All the other authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Portions of the present findings have been presented at three different symposia held at: The 40th Annual European Association for Behavioural and Cognitive Therapies (EABCT) Congress; the 43rd British Association for Behavioural and Cognitive Psychotherapies (BABCP) Annual Conference; the 8th World Congress of Behavioral and Cognitive Therapies (WCBCT).