Journal of Mental Health and Human Behaviour

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 23  |  Issue : 2  |  Page : 86--92

Psychopathology and emotional deficits among patients with psychogenic nonepileptic seizures: A comparative study


Anand Thaman1, Naina Sharma2, Rajeev Gupta1,  
1 Manas Psychology Epilepsy and De-Addiction Centre, Ludhiana, Punjab, India
2 Department of Psychology, Punjabi University, Patiala, Punjab, India

Correspondence Address:
Anand Thaman
Manas Psychology Epilpesy and De-Addiction Centre, Tagore Nagar, Ludhiana, Punjab
India

Abstract

Introduction: Psychogenic nonepileptic seizures (PNESs) are a neuropsychiatric condition involving involuntary episodes of movements, sensation, perception and behaviour which otherwise resemble epileptic seizures (ESs) but without any electrical discharges of brain cortices. High psychiatric comorbidity is found in PNES which may precipitate or perpetuate this condition. Moreover, disruption in emotional processing is attributed as the cause of its onset. Objectives: This study aimed to evaluate the broad psychopathological index and overall symptom distress along with emotional processing deficits as compared to epilepsy and control group. Materials and Methods: The study consisted of three groups, i.e., PNES (n = 37), ES (n = 30), and healthy control group (n = 37). Brief Symptom Inventory measuring nine dimensions of psychiatric symptoms and overall distress was applied for evaluating psychopathological profile of three groups. Emotional processing scale-25 was used to measure emotional processing deficits in five areas. Results: PNES group had higher number of females, higher symptoms of psychopathology, and increased overall symptom distress as compared to ES and control group. Similarly, PNES group showed more deficits while processing their emotions in all areas. Conclusion: Understanding psychopathology and emotional processing deficits in PNES provides clinicians a clearer picture and ready reference for devising biological and psychosocial interventions in these patients.



How to cite this article:
Thaman A, Sharma N, Gupta R. Psychopathology and emotional deficits among patients with psychogenic nonepileptic seizures: A comparative study.J Mental Health Hum Behav 2018;23:86-92


How to cite this URL:
Thaman A, Sharma N, Gupta R. Psychopathology and emotional deficits among patients with psychogenic nonepileptic seizures: A comparative study. J Mental Health Hum Behav [serial online] 2018 [cited 2019 Dec 16 ];23:86-92
Available from: http://www.jmhhb.org/text.asp?2018/23/2/86/270987


Full Text



 Introduction



Psychogenic nonepileptic seizures (PNES) are a neuropsychiatric condition involving involuntary episodes of movements, sensation, perception and behaviour (crying, vocalization, expression of emotions, etc.) which otherwise superficially resembles epileptic seizures (ESs) but without any electrical discharges of brain cortices. Cases of PNES are frequently seen in both neurology and psychiatric clinics. This is the reason International League Against Epilepsy has considered it among ten key neuropsychiatric issues in epilepsy.[1] About 20% of individuals, who experience seizure of any kind, receive final diagnosis as PNES.[2]

Multiple etiologies have been proposed to explain PNES. Beside some predisposing biological vulnerabilities, it is mostly explained through psychosocial and cognitive variables. According to these, PNES occurs when individual's capacity to integrate or synthesize mental components seriously impairs during high stress and intense emotional situations. It causes disturbances in voluntary control increases suggestibility and breakdown of psychological system.[3],[4] During the episode, all painful, traumatized, distressful and forbidden emotions bypass conscious experiences and dissociate themselves from awareness and finally manifest into somatic and cognitive symptoms.[5] Further, it is a pathological cognitive mechanism in response to sudden distress or may be reinforced maladaptive coping style to deal with life stressors.[6] It has been documented that patients with PNES report more incidents of the past or current history of sexual or physical abuse or traumas,[7] unresolved chronic stressors,[8],[9] unhealthy family or interpersonal relationships,[9] communication, and interactional difficulties[10] in their lives.

Moreover, PNES patients have far more psychiatric disorders or psychopathology than in epileptic patients or the general population.[11],[12],[13] One or more comorbid psychiatric conditions exist in almost all PNES patients during the course of their illness.[14] Lifetime prevalence of psychopathology has been found, especially depressive disorders (57%–85%), anxiety/panic disorders (11%–50%), somatization and pain disorders (22%–84%), post-traumatic stress disorder (35%–49%), dissociative disorders (22%–91%), and personality disorders (10%–86%).[15],[16],[17] Dissociative and somatization disorders are the most common findings in PNES patients.[11],[18] This psychopathology further contributes to physical, psychological, and emotional distress in these patients than epilepsy and the general population.[19]

Further, the role of emotions (explicit or implicit) as a contributory factor is described in almost all theories of dissociation or conversion[20],[21],[22],[23] which are the key components of PNES. It is assumed that PNES is actually a manifestation of abnormal emotional processing.[24] PNES patients inconsistently process their emotions with limited options. During emotional processing, they become either overly focused on certain emotions or show excessive avoidance and also find it difficult to identify, express, and regulate their emotions.[21],[25] Emotional regulation a process responsible for the monitoring, evaluation, and modulation of emotional reaction to accomplish one's goal[26] is either seriously disturbed or malfunctioned in PNES patients. These patients report significantly high emotional suppression and less cognitive reappraisal than healthy control while processing their emotions.[27],[28],[29]

An extensively studied component “alexithymia” which is an inability to express affect verbally leading to manifestation of inner psychic distress in the form of physical complaints[30] has been found higher in PNES patients as compared to normal population.[28],[31],[32] Similarly, increased level of emotional avoidance and its positive correlation with the onset of PNES has been constantly reported.[20],[21],[33],[34],[35] Thus, PNES patients show deficits in all areas of emotional processing, i.e., perception, awareness, appraisal, expression, modulating, and regulating as compared to healthy individuals.[36]

Therefore, psychopathology and emotional deficits both together make PNES a tricky puzzle for clinicians and researchers. Because of its overlapping and shared psychopathology with other psychiatric disorders, PNES is considered as a cluster of symptoms rather than a single disorder. On the other hand, studying emotions and its components as a “process”[37] in PNES patients has been recent focused. Only few studies have been done so far and require further evidence to support this model.

The present study aimed to explore detailed psychopathological profile of PNES patients and overall distress generated out of their symptoms. Another aim of this study was to objectively measure emotional processing deficits which were hypothesized as important variable in PNES. Epilepsy and healthy control group were added to study the difference among them in terms of psychopathology and emotional processing deficits.

 Materials and Methods



The current study was conducted at one of the reputed neuropsychiatric hospitals of Ludhiana between the years 2016 and 2017. Sample consisted of three groups – patients with confirmed diagnosis of PNES (n = 37), epilepsy (n = 30), and matched healthy controlled (n = 37). This study was dully approved by Ethical Committee of Punjabi University, Patiala.

Inclusion criteria

  • Confirmed diagnosis of PNES/ES given by neurologist/neuropsychiatrist supported by Video electroencephalograph (vEEG)/EEG/radiological examination and history of symptoms
  • Minimum two seizure episodes with one episode within the past 15 days
  • Age between 16 and 40 years
  • Minimum X passed and able to sign written consent.


Exclusion criteria

  • Coexisting condition (PNES/ES)
  • History of congenital or developmental disorder
  • Psychosis/bipolar depression/major depression/mania as a primary diagnosis
  • Seizures occur solely during alcohol or drug consumption or withdrawal.


Matched control healthy sample

Participants in this group have been recruited from community after matching sociodemographic characteristics with PNES patients and whose score was <10 on PGI health questionnaire (N1) – Hindi version.[38] This questionnaire has 38 questions divided into two sections which screen both physical and psychological symptoms. An overall score of <10 is considered as normal. Written consent was obtained from all the participants.

Tool used

Semi-structured interview pro forma

Semi-structured interview pro forma was devised to collect information on sociodemographic variables including Kuppuswamy socioeconomic status scale.[39]

Brief symptom inventory

This tool is a brief version of Symptom Checklist-90-Revised for measuring symptoms of psychiatric and medical patients. Brief Symptom Inventory (BSI) is 53 items, five-point scale ranging from “not at all” to extremely (0–4). It measures nine primary symptoms dimensions, namely somatization, obsessive compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism. Beside these three global indices, i.e., Global Severity Index (GSI), Positive Symptom Distress Index, and Positive Symptom Total Distress (PSTD) are also generated. Although BSI is not used as a diagnostic tool, still it has clinically sound construct validity and predictive value for psychiatric diagnosis.[40],[41]

Emotional processing scale-25

Revised version of 25 items emotional processing scale (EPS-25) was used in this research. It has five subdomains, namely suppression, unregulated emotions, impoverished emotional experiences, sign of unprocessed emotions, and avoidance. Rating is taken on ten-point scale from completely disagree (0–1) to completely agree is (8-9). Composite score is also calculated to see the overall deficits in emotional processing. Moderate-to-high reliability has been reported for its subdomains.[42],[43]

Both BSI and EPS-25 are self-report measures originally in the English language. For EPS, Hindi version was also available[44] and given to patients. BSI is symptom-based inventory in simple English. However, necessary help was provided to patients in the form of translation/explanation in regional language.

Statistical analysis

Data were analyzed through Microsoft Excel 2007 “add in” advanced statistical tool package. Frequencies, percentage, mean, and standard deviation were calculated for demographical and other variables. One-way ANOVA was performed separately on each dimension of BSI and EPS-25 to see differences in scores of three groups. Further, post hoc Tukey test (Honest significant difference) was applied to evaluate difference of scores in two groups, i.e., PNES versus ES, PNES versus control, and ES versus control.

 Results



In [Table 1], sociodemographical profiles of three groups are given. PNES group had 97% of females with a mean age of 29.97 ± 7.04, 65% were married, 68% belonged to Sikh religion, 54% were from nuclear family, 49% were from urban background, 40% had qualification up to graduation or postgraduation, and 43% from upper middle socioeconomic status.{Table 1}

In ES group, 73% of patients were females, with mean age of 25.23 ± 6.05, 63% were unmarried, 57% were Hindus, 67% belonged to joint families, 40% had qualification up to secondary grade, and 63% came from upper middle socioeconomic status.

Controlled group consisted of 37 participants equally matched with PNES group on sex, age, marital status, nature of habitat, education, and socioeconomic status.

[Table 2] indicates comparison of three groups on BSI scores measuring psychopathology on nine psychiatric dimensions. Results showed that three groups were statistically differed in their mean scores (F value) on all dimensions including three global indices.{Table 2}

When compared two groups, it was found that mean scores of PNES group (Tukey honestly significant difference [HSD]) were significantly higher on all dimensions of psychopathology from ES except PSTD whereas higher from control group on all dimensions including three global indices.

Similarly, mean scores of ES group were significantly higher (Tukey HSD) on somatization, OCD, depression, psychoticism, and on three global indices than control group.

[Table 3] shows comparison of scores for three groups on EPS. Results indicated that mean scores of three groups (F scores) were statistically differed on all dimensions of EPS-25 including overall composite scores.{Table 3}

When scores of two groups compared, it was found that mean scores of PNES group were significantly higher on all areas of emotional processing including composite scores from both ES and control group.

However, no significant difference was found between the mean scores of ES and control group on emotional processing dimensions including overall composite score.

 Discussion



The present study was an attempt to evaluate and compare the psychopathological profile and emotional processing deficits among PNES, ES, and control groups. In this study female predominance was found in PNES as compared to ES group. These results are consistent with previous epidemiological studies wherein 70-80% of female prevalence has been reported in PNES patients.[45],[46],[47],[48] A study from India reported 10:1 female-to-male ratio,[49] whereas in other two studies, females consisted of 84%–95% of total sample.[50],[51] More prevalence of females in PNES has both psychological and biological explanations. Higher incidents of sexual, physical, and emotional traumas[46],[47] along with inherent functional variability of neuro-circuits in brain which are responsible for cognitive and emotional processing make females more vulnerable to PNES in reaction to their stressors.[48]

Mean age of PNES group in the current study is reported as 29.97 ± 7.04, which is consistent with the peak age of onset (18–30 years) reported in literature.[45],[52] Similarly, studies from India described the mean age of PNES between 21 and 29.[49],[50],[51],[52],[53],[54] It is recognized that the third decade of life is a time full of challenges and transitions such as career, job stability, choice of partner, marriage, child rearing, and making adjustment into families which brings lot of psychological and emotional distress.[55] Those who could not cope up with their distress are more prone to varied psychopathology.[6],[55]

In current study PNES group scored significantly higher on all dimensions of psychopathology as compared to ES and control. In other words PNES patients expressed more symptoms of somatization, depression, anxiety, phobic anxiety, paranoid ideation, and psychosis than other two groups. They also had high interpersonal sensitivity and direct or indirect hostility. Both the scores of GSI (measuring overall distress) and PST (reflecting number of symptoms) were found higher in PNES as compared to other two groups. However, no significant difference was observed in PSTD scores of PNES and ES group, indicating the distress of actually reported symptoms.

High comorbid psychopathology in PNES patients as compared to epilepsy had been reported throughout the literature.[56],[57],[58] In review articles, rates of depression were reported between 8.9% and 85% and anxiety between 4.5% and 70%.[58],[59] More prevalence of specific anxiety disorders such as posttraumatic stress disorder (14%–33%), generalized anxiety disorder (GAD) (9%–47%), panic disorder (45%–56%), phobias (2%–33%), and OCD (4%) had also been reported in PNES patients which was significantly higher than the normal population.[60],[61] Somatization which is a predominant defense mechanism used by PNES patients to express psychological distress in the form of physical symptoms had been found higher in PNES patients.[62],[63] Studies conducted in India also reported high prevalence of depression (up to 90%), anxiety (up to 62.3%), and somatization (up to 32%) in PNES patients; however, no comparative study with ES or control group was available.[49],[51]

The prevalence of psychosis in PNES patients had been documented in few studies (7%–20%) which was significantly higher than ES group (3%).[61],[64] Interpersonal sensitivity indicating feeling of inadequacy, insecurity, inferiority, and impoverish interpersonal relationship with significant caregivers[41] had been measured indirectly in few studies. It was found that attachment insecurity with caregivers is reported higher in PNES group as compared to ES and general population, and it has direct relationship with psychopathology and emotional regulation.[65],[66] Similarly, aggression and stress-related emotions such as anxiety and depression were found to be correlated to PNES in few studies.[67],[68],[69]

Comorbidity in psychiatric disorders may represent different manifestations of two stages of the same underlying condition or there may be the same correlated risk factors or one condition may predispose to another disorder.[70] It is argued that symptoms of one disorder can be the direct cause of the arising of other symptoms.[71],[72],[73] For example, symptoms of major depressive episode such as sleep deprivation may cause symptoms of GAD such as irritability and fatigue.[72] Another explanation called liability spectrum which states that comorbidity reflects the existence of smaller number of constructs that underlies multiple disorders.[74] These propositions may also be applied on PNES patients. As psychopathological symptoms already exist in patients which later exaggerate into full fledge PNES episode due to ongoing emotional stressors.

Plethora of studies explained the complex and multidimensional construct of emotions and its role for the onset of PNES. Results of the present study showed high emotional processing deficits in PNES patients as compared to ES and control group. Thus, patients with PNES had more maladaptive coping styles for handling their emotional distress. They were high on suppression, repetitive and intrusive feeling (unprocessed emotions), difficulty in regulation of emotions, excessive avoidance to emotional triggers, and detaching themselves from the actual emotional experiences.

Findings of this research were similar with the results of a previous study using the same emotional processing instrument,[36] which reported significantly higher emotional processing deficits in PNES group on all dimensions as compared to healthy control participants. Other studies measured different components of emotional processing reported consistent findings. For example, the use of expressive suppression to regulate their emotions was found higher in PNES as compare to control group, whereas they use very less cognitive reappraisal to aware and understand their negative emotions.[27] “Alexithymia” which has positive correlation with intrusive experiences, dissociation, and defensive avoidance was found significantly higher in PNES than healthy control.[31] In a separate study, two clusters of PNES patients were found; one with little emotional dysregulation but still had increased avoidance and emotional unawareness and the second who had significant emotional dysregulation and faced high psychiatric issues.[28],[29]

Thus, deficits of emotional processing suggested that PNES patients perceive their distressed emotions as uncontrollable and overwhelming. They may have a fear of being intolerable emotional experiences thus cope either by avoiding them excessively or suppress it through detaching themselves from true feelings. Moreover, they may attribute their emotional experience to external cause such as somatic discomfort and pains. In this way, their emotional dilemma remains unprocessed till it becomes uncontrollable, results into breakdown of already vulnerable cognitive emotional system and ultimately manifests into PNES.

Limitations and implications of the study

The present research has some limitations. It is a cross-sectional study with a small sample size, and data were collected from single center only. Self-reported measures of both BSI and EPS-25 have its own limitations. Further these questionnaires were filled by the patients immediately after the recent episode(s) and during their course of treatment which may give ceiling effects to scores.

However, this study has many practical implications too. It assessed broad psychopathological index in PNES patients and overall symptom distress. Thus, this study focuses more on the presence of symptoms rather clinical diagnosis, as some researchers emphasized that “it is misleading to say comorbidity in PNES rather it is the manifestation of various psychiatric symptoms.”[75] Furthermore, treating PNES alone without considering psychopathological symptoms gives poor outcomes.[76] All psychiatric disorders have their own cognitive, behavioral, and emotional coping mechanisms for which different psychological and medical approach is required. By studying each case separately and their psychopathological index, an individual treatment plan is possible.

Like psychopathology, understanding emotional profile of the patient with PNES also gives an edge to the professionals in the treatment process. Concept of emotional processing has various dimensions ranging from perception of information, awareness to regulation, and expression, and thus, deficits may present at any stage. Results of study will help clinicians to design an interventional plan based on the theoretical model of EP, which may improve emotional processing and ultimately facilitate the patients to be aware and connected to their feelings in a positive and realistic way. Finally, it is perhaps the only study of its own kind in India which attempted to compare and explored psychopathological index along with emotional aspects in PNES, ES, and control groups.

 Conclusion



PNES patients showed higher psychopathological symptoms and distress along with significant deficits in their emotional processing styles. Findings of the current study supported the notion that PNES must not be considered as a single clinical entity, but the cluster of various psychiatric symptoms having common elements. Further, nonpharmacological intervention such as cognitive behavioral therapy needs to be focused more on uninterrupted smooth emotional processing which may help in absorbing traumatic and unpleasant experiences in more adaptive ways.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1Kerr MP, Mensah S, Besag F, de Toffol B, Ettinger A, Kanemoto K, et al. International consensus clinical practice statements for the treatment of neuropsychiatric conditions associated with epilepsy. Epilepsia 2011;52:2133-8.
2Kotsopoulos IA, de Krom MC, Kessels FG, Lodder J, Troost J, Twellaar M, et al. The diagnosis of epileptic and non-epileptic seizures. Epilepsy Res 2003;57:59-67.
3Bowman ES. Why conversion seizures should be classified as a dissociative disorder. Psychiatr Clin North Am 2006;29:185-211, x.
4Kuyk J, Van Dyck R, Spinhoven P. The case for a dissociative interpretation of pseudoepileptic seizures. J Nerv Ment Dis 1996;184:468-74.
5Bowman ES, Markand ON. The contribution of life events to pseudoseizure occurrence in adults. Bull Menninger Clin 1999;63:70-88.
6Tojek TM, Lumley M, Barkley G, Mahr G, Thomas A. Stress and other psychosocial characteristics of patients with psychogenic nonepileptic seizures. Psychosomatics 2000;41:221-6.
7Reilly J, Baker GA, Rhodes J, Salmon P. The association of sexual and physical abuse with somatization: Characteristics of patients presenting with irritable bowel syndrome and non-epileptic attack disorder. Psychol Med 1999;29:399-406.
8Griffith JL, Polles A, Griffith ME. Pseudoseizures, families, and unspeakable dilemmas. Psychosomatics 1998;39:144-53.
9Krawetz P, Fleisher W, Pillay N, Staley D, Arnett J, Maher J. Family functioning in subjects with pseudoseizures and epilepsy. J Nerv Ment Dis 2001;189:38-43.
10Frances PL, Baker GA, Appleton PL. Stress and avoidance in pseudoseizures: Testing and assumptions. Epilepsy Res 1999:34;241-9.
11Lesser RP. Psychogenic seizures. Neurology 1996;46:1499-507.
12Jones SG, O'Brien TJ, Adams SJ, Mocellin R, Kilpatrick CJ, Yerra R, et al. Clinical characteristics and outcome in patients with psychogenic nonepileptic seizures. Psychosom Med 2010;72:487-97.
13Seneviratne U, Briggs B, Lowenstern D, D'Souza W. The spectrum of psychogenic non-epileptic seizures and comorbidities seen in an epilepsy monitoring unit. J Clin Neurosci 2011;18:361-3.
14Turner K, Piazzini A, Chiesa V, Barbieri V, Vignoli A, Gardella E, et al. Patients with epilepsy and patients with psychogenic non-epileptic seizures: Video-EEG, clinical and neuropsychological evaluation. Seizure 2011;20:706-10.
15Reuber M. Psychogenic nonepileptic seizures: Answers and questions. Epilepsy Behav 2008;12:622-35.
16Tellez-Zenteno JF, Patten SB, Jetté N, Williams J, Wiebe S. Psychiatric comorbidity in epilepsy: A population-based analysis. Epilepsia 2007;48:2336-44.
17Gaitatzis A, Trimble MR, Sander JW. The psychiatric comorbidity of epilepsy. Acta Neurol Scand 2004;110:207-20.
18Ettinger AB, Devinsky O, Weisbrot DM, Goyal A, Shashikumar S. Headaches and other pain symptoms among patients with psychogenic non-epileptic seizures. Seizure 1999;8:424-6.
19Baslet G, Roiko A, Prensky E. Heterogeneity in psychogenic nonepileptic seizures: Understanding the role of psychiatric and neurological factors. Epilepsy Behav 2010;17:236-41.
20Goldstein LH, Mellers JD. Ictal symptom of anxiety, avoidance behaviour and dissociation in patients with dissociative seizures. J Neurol Neurosurg Psychiatr, 2006: 77; 616-21.
21Baslet G. Psychogenic non-epileptic seizures: A model of their pathogenic mechanism. Seizure 2011;20:1-3.
22Lesser RP. Treatment and outcome of psychogenic nonepileptic seizures. Epilepsy Curr 2003;3:198-200.
23Goldstein LH, Mellers JD. Recent developments in our understanding of the semiology and treatment of psychogenic nonepileptic seizures. Curr Neurol Neurosci Rep 2012;12:436-44.
24Roberts NA, Reuber M. Alterations of consciousness in psychogenic nonepileptic seizures: Emotion, emotion regulation and dissociation. Epilepsy Behav 2014;30:43-9.
25Williams IA, Levita L, Reuber M. Emotion dysregulation in patients with psychogenic nonepileptic seizures: A systematic review based on the extended process model. Epilepsy Behav 2018;86:37-48.
26Gratz KL, Roemer L. Multidimensional assessment of emotion regulation and dysregulation: Development, factor structure and initial validation of difficulties in emotion regulation scale. J Psychopathol Behav Assess 2004;26:41-54.
27Gul A, Ahmad H. Cognitive deficits and emotion regulation strategies in patients with psychogenic nonepileptic seizures: A task-switching study. Epilepsy Behav 2014;32:108-13.
28Brown RJ, Bouska JF, Frow A, Kirkby A, Baker GA, Kemp S, et al. Emotional dysregulation, alexithymia, and attachment in psychogenic nonepileptic seizures. Epilepsy Behav 2013;29:178-83.
29Uliaszek AA, Prensky E, Baslet G. Emotion regulation profiles in psychogenic non-epileptic seizures. Epilepsy Behav 2012;23:364-9.
30Taylor GJ, Bagby RM, Parker JD. The alexithymia construct. A potential paradigm for psychosomatic medicine. Psychosomatics 1991;32:153-64.
31Myers L, Matzner B, Lancman M, Perrine K, Lancman M. Prevalence of alexithymia in patients with psychogenic non-epileptic seizures and epileptic seizures and predictors in psychogenic non-epileptic seizures. Epilepsy Behav 2013;26:153-7.
32Bewley J, Murphy PN, Mallows J, Baker GA. Does alexithymia differentiate between patients with nonepileptic seizures, patients with epilepsy, and nonpatient controls? Epilepsy Behav 2005;7:430-7.
33Dimaro LV, Dawson DL, Roberts NA, Brown I, Moghaddam NG, Reuber M. Anxiety and avoidance in psychogenic nonepileptic seizures: The role of implicit and explicit anxiety. Epilepsy Behav 2014;33:77-86.
34Bakvis P, Spinhoven P, Zitman FG, Roelofs K. Automatic avoidance tendencies in patients with psychogenic non-epileptic seizures. Seizure 2011;20:628-34.
35Cronje G, Pretorius C. The coping style and health related quality of life of South African patients with psychogenic non-epileptic seizures. Epilepsy Behav 2013;29:581-4.
36Novakova B, Howlett S, Baker R, Reuber M. Emotion processing and psychogenic non-epileptic seizures: A cross-sectional comparison of patients and healthy controls. Seizure 2015;29:4-10.
37Rachman S. Emotional processing. Behav Res Ther 1980;18:51-60.
38Wig NN, Verma SK. PGI health questionnaire: A simple neuroticism scale in India. Indian Journal of Psychiatry 1973;15:80-8.
39Kohili C, Kishor J, Kumar N. Kuppusway's socioeconomic scale-update for July 2015. Int J Prev Curative Community Med 2015;1:1-3.
40Derogatis LR. Brief Symptoms Inventory: Administration and Procedure Manual. Baltimore, US: Clinical Psychometric Research; 1975.
41Derogatis LR, Melisaratos N. The brief symptom inventory: An introductory report. Psychol Med 1983;13:595-605.
42Baker R, Thomas S, Thomas PW, Owens M. Development of an emotional processing scale. J Psychosom Res 2007;62:167-78.
43Baker R, Thomas S, Thomas PW, Gower P, Santonastaso M, Whittlesea A. The emotional processing scale: Scale refinement and abridgement (EPS-25). J Psychosom Res 2010;68:83-8.
44Dubey A, Pandey R. Cross Cultural Validation of Factor Structure of Emotional Processing Scale. Conference Paper ICRAHC. Varanasi: Banaras Hindu University; 2012.
45Asadi-Pooya AA, Sperling MR. Epidemiology of psychogenic nonepileptic seizures. Epilepsy Behav 2015;46:60-5.
46Oto M, Conway P, McGonigal A, Russell AJ, Duncan R. Gender differences in psychogenic non-epileptic seizures. Seizure 2005;14:33-9.
47Myers L, Trobliger R, Bortnik K, Lancman M. Are there gender differences in those diagnosed with psychogenic nonepileptic seizures? Epilepsy Behav 2018;78:161-5.
48Asadi-Pooya AA. Psychogenic nonepileptic seizures are predominantly seen in women: Potential neurobiological reasons. Neurol Sci 2016;37:851-5.
49Patidar Y, Gupta M, Khwaja GA, Chowdhury D, Batra A, Dasgupta A. Clinical profile of psychogenic non-epileptic seizures in adults: A study of 63 cases. Ann Indian Acad Neurol 2013;16:157-62.
50Kumar S, Singh PK, Kumar A. Phenomenology and diagnosis associated with psychogenic non-epileptic seizures. East J Med Sci 2017;2:12-7.
51Khandelwal D, Sharma NK. To study the clinical and neurological profile and assessing the outcomes predictors of patients with psychogenic nonepileptic seizures (PNES): A study of 74 cases. Int J Sci Res 2018;7:24-9.
52Meierkord H, Will B, Fish D, Shorvon S. The clinical features and prognosis of pseudoseizures diagnosed using video-EEG telemetry. Neurology 1991;41:1643-6.
53Krumholz A, Niedermeyer E. Psychogenic seizures: A clinical study with follow-up data. Neurology 1983;33:498-502.
54Dhiman V, Sinha S, Rawat VS, Harish T, Chaturvedi SK, Satishchandra P. Semiological characteristics of adults with psychogenic nonepileptic seizures (PNESs): An attempt towards a new classification. Epilepsy Behav 2013;27:427-32.
55Testa SM, Krauss GL, Lesser RP, Brandt J. Stressful life event appraisal and coping in patients with psychogenic seizures and those with epilepsy. Seizure 2012;21:282-7.
56Bowman ES, Markand ON. Psychodynamics and psychiatric diagnosis of pseudoseizure subjects. Am J Psychiatry 1996;153:57-63.
57Lancman ME, Lambrakis CC, Steinhardt MI. Psychogenic pseudoseizures: A general overview. In: Ettinger AB, Kanner AM, editors. Psychiatric Issues in Epilepsy: A Practical Guide to Diagnosis and Treatment. Philadelphia: Lippincott Williams & Wilkins 200; 1379-90.
58Brown RJ, Reuber M. Psychological and psychiatric aspects of psychogenic non-epileptic seizures (PNES): A systematic review. Clin Psychol Rev 2016;45:157-82.
59Diprose W, Sundram F, Menkes DB. Psychiatric comorbidity in psychogenic nonepileptic seizures compared with epilepsy. Epilepsy Behav 2016;56:123-30.
60de Araujo Filho GM, Ferreira Caboclo LO. Anxiety and mood disorders in psychogenic non-epileptic seizures. J Epilepsy Clin Neurophysiol 2007;13:28-31.
61Scévola L, Teitelbaum J, Oddo S, Centurión E, Loidl CF, Kochen S, et al. Psychiatric disorders in patients with psychogenic nonepileptic seizures and drug-resistant epilepsy: A study of an argentine population. Epilepsy Behav 2013;29:155-60.
62McKenzie PS, Oto M, Graham CD, Duncan R. Do patients whose psychogenic non-epileptic seizures resolve, 'replace' them with other medically unexplained symptoms? Medically unexplained symptoms arising after a diagnosis of psychogenic non-epileptic seizures. J Neurol Neurosurg Psychiatry 2011;82:967-9.
63Reuber M, House AO, Pukrop R, Bauer J, Elger CE. Somatization, dissociation and general psychopathology in patients with psychogenic non-epileptic seizures. Epilepsy Res 2003;57:159-67.
64Alessi R, Valente KD. Psychogenic non-epileptic seizures at a tertiary care center in Brazil. Epilepsy Behav 2013;26:91-5.
65Holman N, Kirkby A, Duncan S, Brown RJ. Adult attachment style and childhood interpersonal trauma in non-epileptic attack disorder. Epilepsy Res 2008;79:84-9.
66Reuber M, Pukrop R, Bauer J, Derfuss R, Elger CE. Multidimensional assessment of personality in patients with psychogenic non-epileptic seizures. J Neurol Neurosurg Psychiatry 2004;75:743-8.
67Walczak TS, Bogolioubov A. Weeping during psychogenic nonepileptic seizures. Epilepsia 1996;37:208-10.
68Gardner DL, Goldberg RL. Psychogenic seizures and loss. Int J Psychiatry Med 1982;12:121-8.
69Mökleby K, Blomhoff S, Malt UF, Dahlström A, Tauböll E, Gjerstad L. Psychiatric comorbidity and hostility in patients with psychogenic nonepileptic seizures compared with somatoform disorders and healthy controls. Epilepsia 2002;43:193-8.
70Rutter M. Comorbidity: Concept, claims and choices. Crim Behav Ment Health 1997;7:265-85.
71Borsboom D, Cramer AO. Network analysis: An integrative approach to the structure of psychopathology. Annu Rev Clin Psychol 2013;9:91-121.
72Borsboom D, Cramer AO, Schmittmann VD, Epskamp S, Waldorp LJ. The small world of psychopathology. PLoS One 2011;6:e27407.
73Bringmann LF, Vissers N, Wichers M, Geschwind N, Kuppens P, Peeters F, et al. Anetwork approach to psychopathology: New insights into clinical longitudinal data. PLoS One 2013;8:e60188.
74Krueger RF, Markon KE. Reinterpreting comorbidity: A model-based approach to understanding and classifying psychopathology. Annu Rev Clin Psychol 2006;2:111-33.
75Beghi M, Negrini PB, Perin C, Peroni F, Magaudda A, Cerri C, et al. Psychogenic non-epileptic seizures: So-called psychiatric comorbidity and underlying defense mechanisms. Neuropsychiatr Dis Treat 2015;11:2519-27.
76Baslet G, Seshadri A, Bermeo-Ovalle A, Willment K, Myers L. Psychogenic non-epileptic seizures: An updated primer. Psychosomatics 2016;57:1-7.