Portuguese validation of the Adult Separation Anxiety—Questionnaire (ASA-27)

Abstract

Despite the prevalence of ASAD, to our knowledge, there is no previous Portuguese validated questionnaire to assess this disorder. [...]the purpose of this study was to develop a Portuguese version of the ASA-27. [...]the items were translated back into English by two trained translators and compared with the original ones. [...]two undergraduate students were inquired about the comprehension and adequacy of the items. Confirmatory factor analysis (CFA) was used to confirm the unique factor structure (all items loading on a single factor). Because of the lack of normality, the sample size (N > 200), and the

About the Authors:

Antonio Ruiz-García

Contributed equally to this work with: Antonio Ruiz-García, Óliver Jiménez, Davinia María Resurrección, Javier Fenollar-Cortés

Roles Conceptualization, Data curation, Writing – original draft, Writing – review & editing

Affiliation: Department of Psychology, Universidad de Córdoba, Córdoba, Spain

Óliver Jiménez

Contributed equally to this work with: Antonio Ruiz-García, Óliver Jiménez, Davinia María Resurrección, Javier Fenollar-Cortés

Roles Conceptualization, Methodology, Writing – original draft

Affiliation: Department of Personality, Assessment and Psychological Treatment, Faculty of Psychology, Universidad de Málaga, Málaga, Spain

ORCID logo https://orcid.org/0000-0003-0314-8396

Davinia María Resurrección

Contributed equally to this work with: Antonio Ruiz-García, Óliver Jiménez, Davinia María Resurrección, Javier Fenollar-Cortés

Roles Conceptualization, Supervision, Writing – original draft, Writing – review & editing

* E-mail: [email protected]

Affiliation: Department of Psychology, Universidad Loyola Andalucía, Seville, Spain

ORCID logo https://orcid.org/0000-0002-0046-8020

Marco Ferreira

Roles Data curation, Methodology, Resources, Writing – original draft, Writing – review & editing

¶‡ These authors also contributed equally to this work.

Affiliation: Instituto Superior de Educação e Ciências, ISEC Lisboa, Lisboa, Portugal

ORCID logo https://orcid.org/0000-0002-5547-4188

José Reis-Jorge

Roles Data curation, Investigation, Methodology, Validation, Writing – review & editing

¶‡ These authors also contributed equally to this work.

Affiliation: Instituto Superior de Educação e Ciências, ISEC Lisboa, Lisboa, Portugal

ORCID logo https://orcid.org/0000-0002-8031-600X

Javier Fenollar-Cortés

Contributed equally to this work with: Antonio Ruiz-García, Óliver Jiménez, Davinia María Resurrección, Javier Fenollar-Cortés

Roles Data curation, Formal analysis, Methodology, Software, Writing – original draft

Affiliation: Department of Psychology, Universidad Loyola Andalucía, Seville, Spain

ORCID logo https://orcid.org/0000-0001-6154-8836

Introduction

Separation anxiety disorder (SAD) was considered a childhood and youth disorder until the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) [1–3]. Nowadays, DSM includes the onset in childhood but also occurring during adulthood, with different clinical manifestations [4–8]. Additionally, a recent study found that a third of the diagnoses during childhood continued during adulthood [9].

Adult separation anxiety disorder (ASAD) showed similar clinical manifestations than in the children population. Specifically, in adults, the symptoms of the disorder are high anticipatory anxiety about symbolic or real separation from the home or attachment figures [10], offspring leaving the parental home, the end of a relationship [11] or moving to a new city. In addition, thoughts of harm or worry about befalling the attachment figures may occur, particularly in cases of separation from, or need to stay in touch with the attachment figures [12–14]. Several studies have highlighted that almost 43% of people reported the onset of a SAD during their adulthood, more specifically around their twenties [15, 16].

Different studies have found that ASAD has been associated with other anxiety and emotional disorders during adulthood [17] and a higher prevalence of panic disorder or bipolar type 2 disorder [18]. ASAD is associated with several comorbid clinical disorders such as post-traumatic stress disorder, anxiety, prolonged grief, emotional or personality disorders [13, 19–24]. Several studies have found a relationship between ASAD and panic disorder [12, 25–28]. In patients with panic disorder or generalized anxiety disorder, the comorbidity between the diagnosis and ASAD is almost 40% [29]. In this line, other studies have found that ASAD was comorbid with bipolar type 1 disorder [25, 30,31].

The lifetime prevalence of ASAD in the general population is 4.8%, being higher in low-middle income countries (5.5%) than in middle- and high-income countries (4.7%) [32]. Higher prevalence was found in Colombia and the United States (9.8% and 9.2%, respectively). In Europe prevalence rates are 1.2% in Spain, 2% in Germany and 3.5% in France. Noteworthy is the prevalence in Portugal (6.4%) with one of the highest rates in high-income countries [32]. However, these studies have a major limitation: they were conducted with retrospective cohorts and assessed ASAD employing a modification of the DSM-IV A criteria of SAD to adapt it to adults [33]. This limitation needs to be taken into account and there is a need to carry out new prospective cohort studies with the DSM-5 criteria [4].

ASAD prevalence is higher among women than men [32]. Specifically, the proportion of cases is higher among women with low-middle sociocultural status who might have overcome adversities during childhood, lived in a dysfunctional family environment or been exposed to traumatic experiences [9]. These risk factors can trigger the development of the SAD both during childhood and adulthood [9]. Specifically, in Portugal the lifetime prevalence is higher among women (7.2%) than in men (5.7%) [32].

Despite the relevance of the ASAD, there are few instruments designed to assess this disorder in the adult population. The first instrument to evaluate ASAD was the Adult Separation Anxiety Questionnaire (ASA-27) [34] based on the first clinical interview designed to assess this disorder. The ASA-27 questionnaire contains 27 items with a four Likert-type response options and has been adapted to the Turkish population [35] and Spanish population [33]. Both validations have shown adequate psychometric properties. Cronbach’s alpha internal consistency were .92 and .93 for the Spanish validation and the Turkish validation, respectively [33, 35]. The Spanish validation loaded on a single factor as the original validation of the ASA-27 (33, 34].

Despite the prevalence of ASAD, to our knowledge, there is no previous Portuguese validated questionnaire to assess this disorder. Therefore, the purpose of this study was to develop a Portuguese version of the ASA-27. Specific objectives were: (a) to adapt ASA-27 questionnaire to the Portuguese population; (b) to assess the psychometric properties, internal consistency, and convergent validity; and (c) to provide clinical criteria for the clinical population.

Materials and methods

Participants

The whole sample (N = 267) included 73 men (27.3%) with a mean age of 46.1 years (SD = 14.1) and 194 women (72.7%) with a mean age of 38.3 (SD = 12.0) years. The overall mean age of the combined sample was 40.5 years (SD = 13.1). They were mostly employed (82.4%), with a bachelor’s degree or higher (79.8%), living with their own family (59.9%), and having no treatment (74.2%) (see Table 1). The sample was large enough given the model structure with a single latent variable [36].

[Figure omitted. See PDF.]

Table 1. Demographic characteristics of Portuguese sample (n = 267).

https://doi.org/10.1371/journal.pone.0248149.t001

Measures

The instrument ASA-27 was translated to Portuguese with the parallel back-translation procedure [37, 38] independently by two bilingual researchers (MF and JRJ). First, the items were translated from English to Portuguese and discrepancies were solved among the two researchers. Second, the items were translated back into English by two trained translators and compared with the original ones. Finally, two undergraduate students were inquired about the comprehension and adequacy of the items. We found no major difficulties with the semantic equivalent of the items in the Portuguese version (see S1 Table in S1 File). In order to assess convergent validity of the questionnaire, several instruments assessing similar constructs have been used, such as trait-state anxiety, attachment and emotional dependence.

State-Trait Anxiety Inventory (STAI) [39, 40]. This inventory assesses state and trait anxiety with 40 Likert-type items. The Portuguese validation showed a good internal consistency for both State anxiety and Trait anxiety (Cronbach’s alpha .80 and .90, respectively).

Composite Codependency Scale (CCS) [41, 42]. This scale assesses codependence with 19-items Likert-type scale from 1 (strongly disagree) to 5 (strongly agree). This scale has three subscales and a total scale, all showing good internal consistency (Cronbach’s alpha: interpersonal control = .67; self-sacrifice = .74; and emotional suppression = .75; total scale = .80).

Procedure

Data collection was done through an online survey. The online questionnaire included socio-demographic outcomes: age, gender, educational level, home environment, work status, marital status, medical status.

The inclusion criteria were being an adult (>18 years old), having Portuguese nationality, and being able to understand Portuguese. In order to include the largest possible number of participants from different age groups and backgrounds we started by sending the questionnaire to our private and professional contacts and asked them to forward it to their own contacts. From 326 responses, 59 of them were excluded for not meeting the criteria. The sample was recruited using a snowball sampling method. There was no reward for participation in the study.

Participants were informed and provided informed consent to participate in the study. The study protocol was approved by the Ethics Commission of Direção Geral para a Investigação e Desenvolvimento, ISEC Lisboa.

Data analysis

Descriptive statistics, Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), internal consistency, and incremental validity were calculated both with the overall sample; analyses were also conducted by gender and age range groups. Given the data distribution a Principal Axis Factor was chosen as factor extraction method [43]. The scree plot was used to determine the number of factors to retain–looking for the break point in the data where the curve flattens out-, a procedure recommended by Costello & Osborne (2005) [44]. Minimum values of 0.32 for factor loadings [45] and 0.80 for KMO statistic were stablished [46]. Confirmatory factor analysis (CFA) was used to confirm the unique factor structure (all items loading on a single factor). Because of the lack of normality, the sample size (N > 200), and the ordinal data, mean and variance adjusted weighted least squares (WLSMV) was selected [47]. Fit measures were computed, such as the χ2 statistic, the root mean square error approximation (RMSEA), the CFI, and the TLI. The standard for good model fit was as follows: (a) CFI ≥ 0.95, (b) RMSEA ≤ 0.06, and (c) SRMR ≤ 0.06 [48]. Internal consistency was assessed using McDonald’s ω [49], defined as the proportion of item variance explained by the latent factors, and Cronbach’s α (to compare with the original scale reliability results). McDonald’s ω was calculated omitting each of the items, with the inclusion criterion that the internal consistency should be no greater than that of the scale without the omission of items.

Possible differences between groups (gender and age range groups, respectively) were also tested. Mann-Whitney analyses were run, and the effect size was calculated. A correlation of .10 is considered a small effect, a correlation of .30 is considered a medium effect, and a correlation of .50 is considered a large [50].

Partial correlation analyses (aged adjusted) were carried out between the total score for the Portuguese version of ASA-27 and the rest of the scales for convergent validity. Regarding incremental validity, hierarchical linear regression models were tested by steps to explore whether the Portuguese version of ASA-27 had a unique predictive power over STAI subscales total scores compared with CCS total score.

CFAs were computed using Mplus [51], and the rest of the analyses were computed with JASP version 0.11.1 [52].

Results

Factor analyses and reliability

Descriptive statistics for the items included in the Portuguese version of ASA-27 are shown in Table 2.

[Figure omitted. See PDF.]

Table 2. Descriptive statistics of the Portuguese version of ASA-27.

https://doi.org/10.1371/journal.pone.0248149.t002

The factors tested (variance, covariance, mean, median, standard deviation, skewness, kurtosis and Standardized Factor Loadings) are presented in Table 3.

[Figure omitted. See PDF.]

Table 3. Variance (diagonal), covariance and standardized factor loadings of items from CFA of the Portuguese version of the ASA-27.

https://doi.org/10.1371/journal.pone.0248149.t003

EFA suggested a single-factor structure with items loading from .322 (tem 3) to .798 (item 14). As can be seen in Fig 1, the curve quickly flattens out after the first factor. The explained variance for the first factor was 32.5% (a possible second factor explained 4.7% of the variance). The goodness of fit of the EFA was adequate (KMO = .915).

[Figure omitted. See PDF.]

Fig 1. Scree plot for the Exploratory Factor Analysis (EFA) of the Portuguese validation of the Adult Separation Anxiety—questionnaire (ASA-27).

https://doi.org/10.1371/journal.pone.0248149.g001

The unidimensional model was proposed for the CFA (every item loading on a single factor), the same as in the original validation of the measure [34]. The unique factor model showed adequate fit indices for the overall sample and all subsamples (see Table 4). For the overall sample, CFI and TLI were higher than .90—the minimum value in order to ensure that misspecified models are not accepted [48]—but slightly lower than .95. RMSEA value was lower than .06. Relative normed chi-square was within the adequate range (χ2/df = 1.91). Item residual variances ranged between .186 (item 3) and .733 (item 14); therefore, there were no negative values for residual variances. As evidence of reliability, the omega coefficient was high (ω = .92); that is, more than 90% of item variance was explained by the latent factor.

[Figure omitted. See PDF.]

Table 4. Goodness-of-fit and reliability indices for the Portuguese version of ASA-27 obtained by gender and age-range groups.

https://doi.org/10.1371/journal.pone.0248149.t004

When the CFAs were re-run by groups, mixed results were found. However, it should be considered that samples were quite small for some groups. So, we should be careful in the interpretation of these results. While the larger sample groups (i.e., «women», «18–35» and «36–25» groups) showed adequate goodness-of-fit, the shorter sample groups (i.e. «men» and «51–80» groups; both groups with fewer than 100 cases) showed poor goodness-of-fit.

Differences between age and gender

Kolmogorov-Smirnov tests indicated that ASA-27 score did not follow a normal distribution (D(267) = .130, p< .001), so non-parametric statistics were calculated. The analysis revealed the existence of differences in ASA-27 scores according to gender (U = 5845.0, p = .028) but not for the age range group (χ2(2) = 5.20, p = .074). The Mann-Whitney test indicated that ASA-27 scores were higher for women (Mdn = 14.5) compared with men (Mdn = 13.0), but the effect size was small (r = -.16). Regarding the post-hoc analysis for age range, there were significant differences between «18 to 35» (Mdn = 15.5) and «36 to 50» groups (Mdn = 13.0) in ASA-27 median scores (U = 6066.5, p = .028) with small effect size (r = .18). There were no differences between the «51 to 80» group and the rest of the age range groups.

Convergent and incremental validity correlations

Age was significantly correlated with ASA-27 the Portuguese Version of ASA-27 (r = -.13, p = .032), STAI Trait (r = -.13, p = .044), and Self-Sacrifice (r = .17, p = .007). No more significant correlations were found. Spearman and Partial correlations (age-adjusted) between the Portuguese version of the ASA-27 with STAI and CCS scales are displayed in Table 5. All correlations between ASA-27 and STAI scales were large and significant. Results were similar by gender. Higher scores on both the state and trait anxiety were associated with significantly higher scores on the Portuguese version of the ASA-27 for every sample (overall, men and women samples). Correlations were slightly higher in the women sample than in the other samples.

[Figure omitted. See PDF.]

Table 5. Convergent validity of the Portuguese version of the ASA-27 (age adjusted).

https://doi.org/10.1371/journal.pone.0248149.t005

However, while all the correlations between ASA-27 and CCS total score and subscales were significant for the overall sample (small to medium effect), results were different by gender samples. Both for overall and women samples, higher scores on ASA-27 were significantly associated with higher scores on CCS total score and subscales. In contrast, scores on the CCS total and subscales were not significantly related to ASA-27 scores for the men sample.

Regarding incremental validity, Table 6 shows the results from the hierarchical linear regression models to explore the unique predictive value of the Portuguese version of ASA-27 over CCS on STAI. Gender, but not age, was a substantive predictor of STAI scales. When CCS subscales were added, Suppression of Emotions subscale was a better predictor of STAI subscales than the gender (although gender improved their standardized regression coefficients). In the next step, ASA-27 score was added, and the magnitude of the standardized regression coefficients for the Suppression of Emotions subscale was reduced, although still significant. The ASA-27 added moderate incremental improvements to the amount of variance accounted by the models on scores of STAI scales (ΔR2 = 23, p < .001 for STAI-State; ΔR2 = 24, p < .001 for STAI-Trait). Therefore, the Portuguese Version of the ASA-27 had a moderate to high unique predictive value, relative to the CCS on anxiety both as trait and state.

[Figure omitted. See PDF.]

Table 6. Hierarchical regression analyses on anxiety measures.

https://doi.org/10.1371/journal.pone.0248149.t006

Discussion

In the last two decades, the relevance of separation anxiety in adulthood has been highlighted [6]. In this context, the creation and development of new instruments adapted for the adult population is needed.

The main objective of the present study was to develop and to analyse the psychometric properties of a Portuguese version of the ASA-27 with a non-clinical sample of Portuguese adults. This is the first instrument available to assess ASAD in the Portuguese population. Overall, the psychometric properties of the instrument were good when considering a one factor structure. The analysis of the factor structure yielded conclusive results, as in the other validation studies and the original instrument [33–35].

The factorial structure of the questionnaire has been shown to be unifactorial, that is, all items load in a single factor, as in the original version [34] and in its adaptations to Turkish [35] and Spanish [33]. However, in this study the adjustment was slightly higher in the RMSE index for men, although confirmatory factor analyses by groups (men and women) have been performed in small groups. Therefore, it would be necessary to confirm it with larger samples of both men and women. However, the adjustment is adequate for the total sample.

Our results support the instrument’s convergent validity, with a total ASA-27 score correlated positively with co-dependency scale and both anxiety state and trait. The data yields interesting results regarding gender and age. ASA-27, in both the overall sample and women sample, correlated positively with CCS total and subscales scores, but these results were not significant for the men group. However, ASA-27 correlated positively with the STAI both in trait and state also in the men sample. Yet these results were not found in previous adaptations [33, 35], which might support the fact that ASAD is associated with being women [20]. These differences might show different profiles between genders. Despite group differences, the model showed an appropriate goodness-of-fit.

Due to the absence of specific instruments to assess ASAD among the Portuguese population, the present study has important theoretical implications. This study yields empirical support to the notion of the new diagnosis of ASAD recently included in DSM-5. In addition, the availability of this scale has practical implications allowing a more accurate diagnosis of anxiety problems comorbid with ASAD. The availability of this instrument can be very useful for clinicians in evaluating other cases, seeing their psychological intervention improved when considering emotional aspects such as separation anxiety, which are usually not considered when addressing other psychological problems such as other types of anxiety problems, or depressive problems [53]. In this regard a recent study found that ASAD was highly prevalent in non-responders to standard anxiety treatment [49]. The development of instruments to assess this novel diagnosis can provide novel information about separation anxiety being a transdiagnostic variable. Therefore, properly detecting separation anxiety problems must be an important objective to improve treatments and their effectiveness, to solve clinical issues.

Some limitations should be considered. Firstly, despite the sample size, a snowball procedure was followed reflecting some consequences of a convenience sample. Data collection could be improved through using for example random sampling procedures. Secondly, although above the minimum for the implemented psychometric techniques, it would be useful to test psychometric properties with larger men samples or with different educational levels to increase the power of the analyses. Finally, it would be interesting for future studies to examine the relationship of ASA-27 with other related constructs such as dependent personality. Future studies should address normative data of the ASA-27 Portuguese for clinical population.

Conclusion

The main scientific benefit of using this scale validation analysis is developing the habit of asking fundamental questions about the construct investigated. In this study, ASA-27 Portuguese was found to be a reliable and valid instrument in assessing the presence of separation anxiety symptoms in adults. The time spent to complete the scale is reduced, which can increase its reliability. This instrument can be useful to obtain accurate information about the diagnosis of SAD in adulthood. In other words, the results can be consistently reproduced. Furthermore, the satisfactory internal consistency and stability scores supported its good reliability. All the findings support the conclusion that ASA-27 questionnaire is an adequate measure of ASAD and can be used with confidence among the Portuguese population.

Supporting information

S1 File.

https://doi.org/10.1371/journal.pone.0248149.s001

(DOCX)

Citation: Ruiz-García A, Jiménez Ó, Resurrección DM, Ferreira M, Reis-Jorge J, Fenollar-Cortés J (2021) Portuguese validation of the Adult Separation Anxiety—Questionnaire (ASA-27). PLoS ONE 16(3): e0248149. https://doi.org/10.1371/journal.pone.0248149

References

1. American Psychiatric Association (APA). Diagnostic and Statistical Manual of Mental Disorders (DSM-5), 5th Ed. Arlington: American Psychiatric Association; 2013.

2. Milrod B, Markowitz JC, Gerber AJ, Cyranowski J, Altemus M, Shapiro T, et al. Childhood separation anxiety and the pathogenesis and treatment of adult anxiety. Am J Psychiatry. 2014; 171(1): 34–43. pmid:24129927

3. Schneier FR, Moskow DM, Choo T-H, Galfalvy H, Campeas R, Sanchez-Lacay A. A randomized controlled pilot trial of vilazodone for adult separation anxiety disorder. Depress Anxiety. 2017; 34(12): 1085–1095. pmid:29071764

4. Bögels S, Knappe S, Clark LA. Adult separation anxiety disorder in DSM-5. Clin Psychol Rev. 2013; 33: 663–674. pmid:23673209

5. Manicavasagar V, Marnane C, Pini S, Abelli M, Rees S, Eapen V. et al. Adult Separation Anxiety Disorder: A disorder comes of age. Curr Psychiatry Rep. 2010; 12: 290–297. pmid:20552302

6. Manicavasagar V, Silove D. Why are we still missing adult separation anxiety disorder in clinical practice? Aust N Z J Psychiatry. 2016; 50(8): 807–808. pmid:27343899

7. Park S-C, Kim Y-C. Anxiety Disorders in the DSM-5: Changes, Controversies, and Future Directions. In: Kim Y-C, editor. Anxiety Disorders. Advances in Experimental Medicine and Biology. Singapore: Springer; 2020. pp. 187–196. https://doi.org/10.1007/978-981-32-9705-0_12 pmid:32002930

8. Silove DM, Rees S. Separation anxiety disorder across the lifespan: DSM-5 lifts age restriction on diagnosis. Asian J Psychiatr. 2014; 11: 98–101. pmid:25453710

9. Carmassi C, Gesi C, Massimetti E, Shear MK, Dell’Osso L. Separation anxiety disorder in the DSM-5 era. Journal of Psychopathology. 2015; 21: 365–371.

10. Silove DM, Slade T, Marnane C, Wagner R, Brooks R, Manicavasagar V. Separation anxiety in adulthood: dimensional or categorical? Compr Psychiatry. 2007; 48(6): 546–53. pmid:17954140

11. Mabilia D, Di Riso D, Liso A, Bobbio A. A Prediction Model for Separation Anxiety: The Role of Attachment Styles and Internalizing Symptoms in Italian Young Adults. J Adult Dev. 2019; 26: 286–294. https://doi.org/10.1007/s10804-019-09327-y

12. Gesi C, Abelli M, Cardini A, Lari L, Di Paolo L, Silove D, et al. Separation anxiety disorder from the perspective of DSM-5: clinical investigation among subjects with panic disorder and associations with mood disorders spectrum. CNS Spectr. 2015; 21(1): 70–75. pmid:25704393

13. Pozzi G, Bruschi A, De Angelis A, Pascucci M, Hatzigiakoumis DS, Grandinetti P, et al. Adult separation anxiety and TCI-R personality dimensions in patients with anxiety, alcohol use, and gambling: A preliminary report. J Biomed Biotechnol. 2014; 5: 680985. https://doi.org/10.1155/2014/680985

14. Posavac SS, Posavac HD. Adult separation anxiety disorder symptomology and susceptibility to marketing persuasion. J Soc Clin Psychol. 2017; 36(2): 158–169. https://doi.org/10.1521/jscp.2017.36.2.158

15. Kessler RC, Üstün TB. The World Mental Health (WMH) survey initiative version of the World Health Organization (WHO) Composite International Diagnostic Interview (CIDI). Int J Methods Psychiatr Res. 2004; 13: 93–121. pmid:15297906

16. Shear K, Jin R, Ruscio AM, Walters EE, Kessler RC. Prevalence and correlates of estimated DSM-IV child and adult separation anxiety disorder in the National Comorbidity Survey Replication. Am J Psychiatry. 2006; 163: 1074–1083. pmid:16741209

17. Dell’Osso L, Carmassi C, Corsi M, Pergentini I, Socci C, Maremmani A, et al. Adult separation anxiety in patients with complicated grief versus healthy control subjects: relationships with lifetime depressive and hypomanic symptoms. Ann Gen Psychiatry. 2011; 10: 29. pmid:22032687

18. Hale WW, Berg A, Malhotra S. An examination of separation anxiety disorder symptoms in adults from a clinical population. J Syst Integr Neurosci. 2018; 4(2): 1–5. https://doi.org/10.15761/JSIN.1000198

19. Bruschi A, De Angelis A, Grandinetti P, Pastucci M, Janiri L, Pozzi G. Disturbo d’ansia di separazione dell’adulto: evidenze di letteratura e implicazioni cliniche. Riv Psichiatr. 2012; 47(5): 355–364. pmid:23160046

20. Carmassi C, Gesi C, Corsi M, Pergentini I, Cremone IM, Conversano C, et al. Adult separation anxiety differentiates patients with complicated grief and/or major depression and is related to lifetime mood spectrum symptoms. Compr Psychiatry. 2015; 58: 45–49. pmid:25595519

21. Dogan D, Yoldas C, Kocabas O, Memis CO, Sevincok D, Sevincok L. The characteristics of the comorbidity between social anxiety and separation anxiety disorders in adult patients. Nord J Psychiatry. 2019; 73(6): 380–386. pmid:31322453

22. Gesi C, Carmassi C, Shear KM, Schwartz T, Ghesquiere A, Khaler J, et al. Adult separation anxiety disorder in complicated grief: an exploratory study of frequency and correlates. Compr Psychiatry, 2017; 72: 6–12. pmid:27683967

23. Möller EL, Bögels SM. The DSM-5 Dimensional Anxiety Scales in a Dutch non-clinical sample: psychometric properties including the adult separation anxiety disorder scale. Int J Methods Psychiatr Res. 2016; 25(3): 232–239. pmid:27378317

24. Pini S, Abelli M, Troisi A, Siracusano A, Cassano GB, Shear KM, et al. The relationships among separation anxiety disorder, adult attachment style and agoraphobia in patients with panic disorder. J Anxiety Disord. 2014; 28: 741–746. pmid:25218272

25. Costa B, Pini S, Baldwin DS, Silove D, Manivasagar V, Abelli M, et al. Oxytocin receptor and G-protein polymorphisms in patients with depression and separation anxiety. J Affect Disord. 2017; 218: 365–373. pmid:28499211

26. Kossowsky J, Pfaltz MC, Schneider S, Taeymans J, Locher C, Gaab J. The separation anxiety hypothesis of panic disorder revisited: a meta-analysis. Am J Psychiatry. 2013; 170(7): 768–781. pmid:23680783

27. Pini S, Abelli M, Shear KM, Cardini A, Lari L, Gesi C, et al. Frequency and clinical correlates of adult separation anxiety in a sample of 508 outpatients with mood and anxiety disorders. Acta Psychiatr Scand. 2010; 122: 40–46. pmid:19824987

28. Silove DM, Marnane CL, Wagner R, Manicavasagar VL, Rees S. The prevalence and correlates of adult separation anxiety disorder in an anxiety clinic. BMC Psychiatry, 2010; 10: 10–21. pmid:20109169

29. Manicavasagar V, Silove D, Curtis J, Wagner R. Continuities of separation anxiety from early life into adulthood. J Anxiety Disord. 2000; 4: 1–18. pmid:10770232

30. Perugi G, Toni C, Maremmani I, Tusini G, Ramacciotti S, Madia A, et al. The influence of affective temperaments and psychopathological traits on the definition of bipolar disorders subtypes: A study on Bipolar I Italian national sample. J Affect Disord. 2012; 136: e41–e49. pmid:20129674

31. Pini S, Abelli M, Mauri M, Muti M, Lazzetta P, Banti S, et al. Clinical correlates and significance of separation anxiety in patients with bipolar disorder. Bipolar Disord. 2005; 7(4): 370–376. pmid:16026490

32. Silove DM, Alonso J, Bromet E, Gruber M, Sampson N, Scott K, et al. Pediatric-onset separation and Adult-onset Separation anxiety disorder across countries in the World Mental Health Survey. Am J Psychiatry. 2015; 172: 647–656. pmid:26046337

33. Ruiz-García A, Jiménez Ó, Fenollar-Cortés J, Cano-Marín J, Ojeda-Mora MA, Selva Á, et al. Adaptación y validación al español del Cuestionario de Ansiedad por Separación en el Adulto (ASA-27). RIDEP. 2019; 53(4): 153–167. https://doi.org/10.21865/RIDEP53.3.12

34. Manicavasagar V, Silove D, Wagner R, Drobny J. A self-report questionnaire for measuring separation anxiety in adulthood. Compr Psychiatry. 2003; 44(2): 146–153. pmid:12658624

35. Dirioz M, Alkin T, Yemez B, Onur E, Eminagaoglu B. The validity and reliability of Turkish version of Separation Anxiety Symptom Inventory and Adult Separation Anxiety Questionnaire. Turk Psikiyatri Derg. 2012; 23(2): 108–116. https://doi.org/10.5080/u6364 pmid:22648873

36. Kline RB. Principles and practice of structural equation modeling. Nueva York: The Guilford Press; 2016.

37. Brislin RW. The wording and translation of research instruments. In Lonner WJ, Berry JW, editors. Field methods in cross-cultural psychology. Newbury Park: Sage Publications; 1986. pp. 137–164.

38. Muñiz J, Elosua P, Hambleton RK. Directrices para la traducción y adaptación de los tests: segunda edición. Psicothema. 2013; 25(2): 151–157. pmid:23628527

39. Spielberger CD, Gorsuch RL, Lushene R, Vagg PR, Jacobs GA. Manual for the State-Trait Anxiety Inventory. Palo Alto: Consulting Psychologists Press; 1983.

40. Silva D. Inventário de Estado-Traço de Ansiedade. In Gonçalves MM, Simões MR, Almeida LS, Machado C, editors. Avaliação psicológica: Instrumentos validados para a população portuguesa, vol. I. Coimbra: Quarteto 2003; pp. 45–63.

41. Marks ADG, Blore RL, Hine DW, Dear GE. Development and validation of a revised measure of codependency. Aust J Psychol. 2011; 64(3): 119–127. https://doi.org/10.1111/j.1742-9536.2011.00034.x

42. Pereira IR. Escala compósita de codependência: adaptação para a população portuguesa: M.Sc. Thesis, Universidade de Lisboa. Faculdade de Psicologia. 2017. Available from: http://hdl.handle.net/10451/33813

43. Fabrigar L. R., Wegener D. T., MacCallum R. C., & Strahan E. J. Evaluating the use of exploratory factor analysis in psychological research. Psychol Methods. 1999; 4(3): 272–299. http://dx.doi.org/10.1037/1082-989X.4.3.272

44. Costello A. B., & Osborne J. Best practices in exploratory factor analysis: Four recommendations for getting the most from your analysis. Practical assessment, research, and evaluation. 2005; 10(1), 7.

45. Tabachnick B. G., & Fidell L. S. (2001). Using multivariate statistics. Boston, MA: Allyn & Bacon.

46. Howard M. C. (2016). A review of exploratory factor analysis decisions and overview of current practices: What we are doing and how can we improve?. Int J Hum-Comput Int. 2016; 32(1): 51–62. http://dx.doi.org/10.1080/10447318.2015.1087664

47. Flora DB, Curran PJ. An empirical evaluation of alternative methods of estimation for confirmatory factor analysis with ordinal data. Psychol Methods. 2004; 9: 466–491. pmid:15598100

48. Hu LT, Bentler PM. Cutoff Criteria for Fit Indexes in Covariance Structure Analysis: Conventional Criteria Versus New Alternatives. Struct Equ Modeling. 1999; 6(1): 1–55. https://doi.org/10.1080/10705519909540118

49. McDonald RP. Test theory: A unified treatment. Mahwah: Lawrence Erlbaum Associates, Inc; 1999

50. Cohen J, Cohen P, West SG, Aiken LS. Applied multiple regression/correlation analysis for the behavioral sciences (3rd ed.) London: Lawrence Erlbaum Associates Publishers; 2003

51. Muthén LK, Muthén BO. Mplus User’s Guide. Seventh Edition. Los Angeles, CA: Muthén & Muthén; 1998–2012.

52. JASP Team (2020). JASP (Version 0.13.1) [Computer software].

53. Milrod B, Altemus M, Gross C, Busch F, Silver G, Christos P, et al. Adult separation anxiety in treatment nonresponders with anxiety disorders: delineation of the syndrome and exploration of attachment-based psychotherapy and biomarkers. Compr Psychiatry. 2016; 66: 139–145. pmid:26995247