Defining the Optimal Threshold Score for Panic Agoraphobic Spectrum - Short Version (PAS-SV) Questionnaire in Clinical and General Population

1.1. Panic Disorder and Agoraphobia

Panic Disorder (PD) is an extremely frequent anxiety disorder, with prevalence rates in the general population of 2.1 and 4.7% [1, 2]. According to the DSM-5-TR, panic disorder is characterized by unexpected and recurrent panic attacks, followed by worry, fear, and behavioral changes [3]. By panic attack, the DSM-5 means a sudden wave of intense fear or intense discomfort that peaks within minutes, and during this time, four (or more) of thirteen symptoms occur, such as palpitation, sweating and trembling [4]. Panic disorder frequently tends to assume a chronic pattern, significantly impacting quality of life and representing a significant healthcare expense. The chronic nature of PD often necessitates long-term management strategies, which can be both resource-intensive and challenging for patients. Effective interventions and timely treatment are crucial in mitigating the long-term impacts on individuals’ daily functioning and overall well-being. These factors suggest the importance of implementing the effectiveness of the prevention, diagnosis and treatment processes [5]. This need appears even more urgent considering the high rate of comorbidity with other mental disorders, concerning 80 percent of individuals with PD, such as major depressive disorder, alcohol and substance use disorder, and other anxiety disorders [6]. These include Agoraphobia (AG), a diagnosis differentiated from panic disorder in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and characterized by fear and anxiety in agoraphobic situations [3]. A diagnosis of AG can be found in 80.9% of individuals with PD, and several studies have concluded that the coexistence of the two disorders results in a worsening of panic disorder in terms of course, prognosis, and response to treatment [7].

1.2. The Spectrum Model

Beyond an overt diagnosis of a mental disorder, numerous studies have shown that even subthreshold psychopathological symptomatology, not reaching the threshold for meeting DSM criteria, is capable of significantly impacting the individual’s quality of life [8-11]. Several studies have shown how even subthreshold psychopathological manifestations are sometimes capable of impairing an individual's functioning, thus meriting early identification [12-20]. Regarding PD and AG (PAD), some authors highlighted that, beyond the DSM criteria, a parade of other panic-agoraphobic symptoms can occur both in individuals diagnosed with PAD and in patients suffering from other mental disorders, such as separation anxiety disorder or mood disorders, without being able to be framed in a proper diagnosis of PD or AG [11, 18, 21, 22]. In order to capture such subthreshold manifestations, a Structured Clinical Interview for the Panic-Agoraphobic Spectrum (SCI-PAS) and the corresponding self-report form (PAS-SR) were developed as part of the Spectrum Project [11]. The long completion time of the questionnaire, corresponding to about 50 minutes, as well as the outdated nature of some items referring to old diagnostic criteria, led to the development of a revised and shortened version of thetool, called the Panic-Agoraphobic - Short Version (PAS-SV) and characterized by. This version showedhigh level of internal consistency and excellent test-retest reliability [22, 23]. However, to date, the PAS-SV lacks a validated threshold to quantitatively establish the presence of PAD as well. The presence of a validated threshold would allow better use of the instrument as a screening tool in clinical and nonclinical settings. Additionally, having a validated threshold can facilitate early intervention by identifying individuals who may not yet meet full diagnostic criteria but are at risk of developing significant symptoms. This proactive approach could potentially reduce the severity of the disorder and improve long-term outcomes.

1.3. Aim

The purpose of this study was to evaluate the best threshold of the PAS-SV for determining the presence of significant panic disorder and agoraphobia (PAD) in a clinical setting and healthy controls (HC).

2.1. Participants and Procedure

For the aims of this study, we evaluated a convenient sample consecutively recruited between September 2022 and December 2023 at the Psychiatric Clinic of the University of Pisa. The sample was composed of two groups: patients with full-blown PD or AG (PAD) and healthy controls (HC). The first group was recruited amongst adult outpatients with a PAD diagnosis according to DSM-5 criteria who were following a treatment program for PAD. The Structured Clinical Interview for DSM-5, Research Version (SCID-5-RV) [24] was used to confirm the diagnosis of PD and AG, as well as the absence of mental disorders among HC subjects. All subjects were clinically assessed according to DSM-5 criteria. Moreover, all subjects completed the PAS-SV and the PDSS (Panic Disorder Severity Scale). All subjects enrolled in this research received clear information about the study and had the opportunity to ask questions before they provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Ethics Committee of Azienda Ospedaliero Universitaria Pisana (reference number 23326).

2.2. Measures

Assessment procedures included the SCID-5-RV [23] and the Panic-Agoraphobic - Short Version (PAS-SV) questionnaire. Evaluations were carried out by psychiatrists, who were trained and certified in the use of the study instruments.

The PAS-SV [22] is composed of 78 items, organized into 4 domains. The first domain investigates the presence of symptoms belonging to a panic attack as described in the DSM-5-TR, while the second domain includes the possible atypical manifestations of panic, i.e., not included within the DSM. The third domain regards the possible concerns and behaviors related to the presence of panic, such as sensitivity to medication, sensitivity to reassurance, and separation anxiety. Finally, the fourth domain explores the presence of agoraphobic and claustrophobic symptoms in different circumstances, both included and not included in the DSM description of “Agoraphobia”. “The PAS-SV was administered in a controlled setting to ensure that participants understood the questions and could respond accurately. The questionnaire's design allows for the assessment of both DSM-5 criteria and subthreshold symptoms, which are critical for capturing the full spectrum of panic and agoraphobic symptoms.

The PDSS is an instrument tailored to evaluate the presence and severity of panic disorder and associated symptoms, featuring seven domains: frequency of panic attacks; distress during panic attacks; anticipatory anxiety; agoraphobic fear and avoidance; interoceptive fear and avoidance; impairment of or interference in work functioning; impairment of or interference in social functioning. Scores are organized on a Likert scale ranging from 0 to 4. A score equal to or above 9 is indicative of a possible PD [24, 25].

2.3. Statistical Analyses

Chi-square tests and ANOVA analyses were employed for comparing socio-demographic variables. The Mann–Whitney U test was used to compare PAS-SV scores among the two groups. A Receiver-Operating Characteristics (ROC) curve was utilized to find the threshold value of the PAS-SV total score that best identifies the subjects meeting the DSM-5 criteria for full-blown PAD. According to the definition of accuracy, the ROC analysis was built on the basis of sensitivity and specificity for different cut-offs. We computed Cohen’s Kappa in order to evaluate the concordance between PAS-SV and PDSS in identifying PD subjects vs HC. Statistical analyses were conducted using SPSS version 26.0 [26].