Teaching differential diagnosis with Anakin Skywalker: the duel between borderline personality disorder and bipolar disorder

Abstract Objective: Previous publications have focused on a leading pop culture phenomenon, Star Wars, to teach several issues in psychiatry, which can make understanding challenging themes easier. This article delves into matters of differential diagnoses regarding two psychiatric disorders. Methods: We examine and compare the symptoms and specificities of borderline personality disorder and bipolar disorder in the light of the fictional villain of the films, Darth Vader/Anakin Skywalker. Results and Conclusion: Our considerations of his diagnosis should be interpreted as an academic exercise with two main goals: to discuss the differential diagnosis between borderline personality disorder and bipolar disorder in an illustrative, soft, and ludic way; and to teach how to connect one’s behaviors with diagnostic criteria - in this case, those related to borderline personality disorder.

Fictional universes may facilitate the exploration of challenging themes and complex definitions.In this paper, we discuss how a popular character from Star Wars can be used in psychiatric discussions with trainees/students to address real-world issues on differential diagnoses between Borderline Personality Disorder (BPD) and Bipolar Disorder (BD).Specifically, we focus on the franchise's most famous fictional character, the villain Darth Vader/Anakin Skywalker.This paper is tongue specific in some places and assumes that the reader has a general knowledge of Star Wars.Finally, when discussing issues related to differential diagnoses between BPD and bipolar disorder BD, the current (categorical) diagnostic system and the main alternative (dimensional) diagnostic system for psychiatric conditions are brought into focus, since they directly impact diagnostic decision-making in the clinic.

Star Wars as a tool for teaching
Research from several scientific disciplines has taken advantage of Star Wars analogies for teaching (e.g., hematology/oncology; ergonomics methods) (Springer, 2014;Walker et al., 2016).Accordingly, Star Wars scenes and characters have been used to teach psychiatric disorders (Friedman & Hall, 2015a, 2015b;Hall & Friedman, 2015).
The Star Wars saga is considered amenable to various complex analyses, maybe as a result of the mythological and religious themes within the storyline (Lyden, 2003).Star Wars presents the requirements to be used as a teaching tool (Hall & Friedman, 2015), described as follows: (a) it is timeless, (b) universal in the scope of themes addressed, (c) well-known, and (d) sufficiently culturally incorporated to become a shorthand for a broader concept.
The main recurrent character in the six episodes is Anakin Skywalker.Anakin later develops into the villain Darth Vader.Some claim this character, probably one of the most well-known villains in the history of cinema, is among the main factors explaining Star Wars' success (Bui et al., 2011).Anakin Skywalker is a Force-sensitive human male, considered the Chosen One by some, and was a Jedi Knight of the Galactic Republic.Details on Anakin Skywalker's traits and history can be found in specific publications (Bray et al., 2017).

What side of the disorder? Darth Vader and the differential diagnoses
From the categorical diagnosis perspective, the literature tends to agree that Anakin Skywalker had BPD (Bui et al., 2011;Carvalho, 2017;Friedman & Hall, 2015a, 2015b;Hall & Friedman, 2015;Tobia et al., 2015), although there are controversies (Rocha et al., 2012).The BPD can be difficult to diagnose because of the symptoms it shares with other conditions, mainly mood disorders (Biskin & Paris, 2012).Specifically, BPD can be misdiagnosed as BD (American Psychiatric Association, 2013).
One meta-analysis (Fornaro et al., 2016) reported that comorbidity between BPD and BD is frequent, with about one in five people presenting a BPD-BD comorbid diagnosis.Although comorbidity is typical and several commonalities are present (Bøen et al., 2015), studies comparing BPD and BD suggest that they are separate and unique (De la Rosa et al., 2017).Our focus is on this premise, i.e., that BPD and BD have separate identities.Therefore, according to this paper's teaching purposes, we are more dedicated to identifying Anakin's primary disorder than discussing the possibility of comorbidity.
Misdiagnosing BPD as BD can occur with both BD-I and BD-II types, although researchers have argued that the similarities with BPD are more typical for the BD-II type and less for BD-I (Bayes et al., 2016).The manic episodes expected in BD-I patients (American Psychiatric Association, 2013) may facilitate its distinction from BPD.These are periods of atypical and persistently high levels of irritable mood, which may include grandiosity, a reduced need for sleep, distraction, racing thoughts, psychomotor agitation, and excessive involvement in activities with potentially painful consequences.According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnostic criteria, from the categorical perspective, patients with BD-II are not expected to present manic episodes but hypomanic episodes, which are less intense than manic episodes (for instance, hypomania does not usually lead to hospitalization).However, the differences between BD-I and BD-II are subtler than anticipated by diagnostic manuals (Novick et al., 2010;Kupka et al., 2007).Therefore, we will distinguish the BD types only when strictly necessary.
Emotional lability, impulsiveness, aggressiveness, depression, and anxiety are shared traits and symptoms between BPD and BD (Bøen et al., 2015;Wilson et al., 2007).Although similar, BPD and BD are distinctly described and categorized by psychiatric manuals as DSM-5 (American Psychiatric Association, 2013).The literature describes BPD as a pattern of impulsivity and general instability, including impairments in interpersonal relationships, self-image, and affects, and characterizes BD-I and BD-II types as having oscillating periods of depression and of abnormally elevated mood, called manic episodes.
Table 1 presents the symptoms and traits typically shared between BPD and BD, compares symptoms and traits in terms of frequency and intensity in each disorder, and informs some specificities on genetics and early events (see the first column).It also presents information regarding Anakin Skywalker (see columns three to five), discussed later in this paper.The last column concludes with a disorder recommendation.
The first step into a differential diagnosis for Anakin Skywalker may proceed from the severity of his pathological functioning.Considering that (a) his behaviors' representative traits are always very extreme (e.g., killing all Tusken Raiders represents the aggressiveness trait), and (b) previous literature suggests BPD as more severe than BD (although similar on Emotional lability) (Bøen et al., 2015;Mazer et al., 2019;Wilson et al., 2007), the most appropriate choice to interpret the traits and symptoms manifested by Anakin seems to be the BPD composition.
The typical symptoms from BD-I (i.e., manic episodes) are not clearly present in Anakin.He manifests signs of grandiosity solidly and recurrently, from his childhood to his adult years.However, as grandiosity is the sole sign related to manic episodes and its manifestation is not episodic, we can conclude that Anakin's grandiosity is an expression of a pathological trait, as previously stated (Carvalho, 2017;Hall & Friedman, 2015;Rocha et al., 2012).Anakin presents six of the nine diagnostic criteria composing BPD (Fornaro et al., 2016).Table 1 helps connect Anakin's behaviors and the diagnostic criteria.However, we showed substantial BPD specifications in Table 2 (e.g., abandonment avoidance, identity disturbance, and intense anger).For instance, we can observe self-related impairments as a form of identity disturbance (Anakin sometimes believes he should agree with the Jedi and sometimes goes against them).We can also see interpersonal impairments, such as the unstable and intense relationship with his wife, Padmé, which drives him to kill her, or with his mother, Shmi, which leads him to extinguish an entire Tusken Raiders village.The presence of self and interpersonal impairments is a reliable indicator of PD (American Psychiatric Association, 2013).As observed, the specificities of the pattern exhibited by Anakin resemble a BPD pattern.Note: a : Midi-chlorians are microscopic, intelligent life forms, and reside within the cells of all living organisms, allowing the Force to speak through them, making some beings sensitive to the Force (Carvalho, 2017); b : e.g., emotional abuse, emotional neglect, and physical neglect.Row cells regarding symptoms or traits are in grey for childhood, as the diagnostic of Borderline Personality Disorder (BPD) and Bipolar Disorder (BD) are based on symptoms and traits presented in adulthood (i.e., ≥ 18 years old).
According to our observations on Star Wars, Anakin presents a BPD pattern mainly related to emotional instability, impulsivity, and aggressiveness traits.Although DSM-5 does not provide BPD subtypes, Anakin's trait profile reflects the BPD impulsive type presented in the 10th revision of the International Classification of Diseases (World Health Organization, 1992).Anakin's BPD pattern is also compatible with the impulsive borderline traits described by Millon (2011), even though Anakin presents restlessness, irritability, and impatience, which is consistent with Millon's petulant borderline personality style.According to Millon (2011), petulant borderlines may be best characterized by extreme unpredictability and restless, irritable, impatient, and complaining behaviors.Nonetheless, Millon (2011) presents the impulsive borderline as seductive, shallow, erratic, intolerant to boredom and routine, and prone to losing control.Note: a : focus was given to anxiety, as irritability is also contemplated within the 8 th criterion; b : quote from Anakin; *: the reader must note that when episodes IV, V, and VI were released, Shmy Skywalker (Anakin's mother) and Padmé Amidala (Anakin's wife) had not yet been created.Therefore, in these episodes, there is no explicit evidence of Anakin's abandonment avoidance, although the Star Wars canon clearly suggests this trait in Vader (e.g., Fortress Vader saga in Star Wars Darth Vader comics 19 to 25).
Although it is possible to reach a conclusion about a probable diagnosis for Anakin, the decision between the diagnosis of BPD or BD is a difficult one (Phelps, 2014;Phillips & Kupfer, 2013), even when considering the diagnostic system that these nosological entities are inserted in (Leibenluft, 2014).In other words, the categorical diagnostic system tends to create artificial differences between functions that are less distinct in real life (Haslam et al., 2012;Leibenluft, 2014).Despite this attempt to differentiate psychopathological categories, for example, BPD and BD share several diagnostic criteria, and, in fact, they look nearly identical in the DSM-5, with the crucial exception of two criteria of BPD, that is, chronic emptiness and fear of abandonment.Unlike the categorical system, a dimensional diagnostic system allows the identification of profiles in which the symptoms and typical characteristics of two theoretically distinct psychiatric disorders are present.The greater flexibility of the dimensional model seems to reflect more adequately the complex human functioning regarding mental conditions and, therefore, several authors assert that a dimensional system has more validity and utility over the categorical model (Widiger & Trull, 2007).
From a dimensional perspective, Anakin possibly would not receive an exclusively BPD or BD diagnosis, but his pathological profile would be set up reflecting his major impairments.Figure 1 illustrates a possible profile for Anakin.The figure was created to reflect the diagnostic criteria presented in Table 2.In addition, the score from 0 to 3 was based on the alternative Model for Personality Disorders (American Psychiatric Association, 2013), where 2 and 3 are indicators of personality pathology.From a dimensional perspective, Anakin's score indicates functioning impairment for six criteria.Efforts to avoid abandonment, identity disturbance, affective instability, and intense anger are the characteristics with the most significant damage in the pathological pattern exhibited by Anakin.In addition, he does not reach the cutoff point for three criteria.As previously pointed out by the literature, the dimensional diagnostic model is more informative compared to the categorical model because, more than just fitting the patient into a category, it informs the clinician about the intensity of the damage in the evaluated pathological characteristics, establishing a clinically relevant profile for decision-making (Haslam et al., 2012;Leibenluft, 2014;Widiger & Trull, 2007).

Conclusion
In conclusion, we present our final word on Anakin Skywalker's diagnosis.However, we forked Anakin's diagnostic judgement both for the categorical perspective, which is the current model, and for the dimensional system, the main alternative model proposed.
Our conclusion was weighted considering previous publications in which psychiatric diagnosis for Anakin included a post-traumatic stress disorder hypothesis, a BPD hypothesis, or even the impossibility of closing in a specific diagnosis.Regarding the title of our paper, from a categorical perspective, the duel between BPD and BD comes to an end, and BPD prevails.In other words, evidence from the Star Wars films (Table 1) and the detailed look at BPD diagnostic criteria (including literature besides DSM) indicate that Anakin Skywalker's pathological pattern resembles the BPD pattern.Therefore, from a categorical perspective, our psychiatric diagnosis of Anakin Skywalker is BPD.
On the other hand, from a dimensional perspective, the diagnosis is more complex, encompassing symptoms and characteristics of both BPD and BD.It is possibly a more detailed diagnosis that truly reflects Anakin's daily pathological functioning since the dimensional model allows the construction of complex profiles composed of symptoms from various disorders.Specifically, from a dimensional perspective, Anakin exhibits a pattern of impairment mainly associated with exaggerated efforts to avoid abandonment, identity disturbance, affective instability, and intense anger.Based solely on a categorical model, Anakin could present a BPD diagnosis, which would imply that he shows, for example, dissociative symptoms and suicidal behavior, not reflecting the precise pathological profile presented by the character.The informative and detailed capacity of the dimensional diagnosis indicates the dangers of believing that we can make the distinction accurately (i.e., decide between one mental diagnosis or another), which can negatively impact clinical interventions.
Although we present a final word regarding Anakin Skywalker's mental disorder diagnosis, these considerations should be interpreted as an academic exercise with two main aims.First, to discuss the differential diagnosis between BPD and BD in an illustrative, soft, and ludic way.Second, to teach how to connect one's behaviors with diagnostic criteria, in this case, specifically related to BPD.We hope our effort with this paper in contributing to the ways to teach using Star Wars may help students and professionals in the mental health field discuss BPD (in contrast to BD).Moreover, we expect our paper to assist professionals in creatively elaborating presentations and lessons on psychiatric disorders and, of course, knowing a little more about the Star Wars universe.Furthermore, we emphasize the need to constantly question our conclusions and adopt a humble, scientific attitude toward our theoretical convictions -as Obi-Wan Kenobi would say, "Only a Sith deals in absolutes."

Figure 1
Figure 1Borderline Personality Disorder Dimensional profile of Anakin Skywalker

Table 1
reveals that Anakin's pattern resembles a BPD diagnosis more than a BD diagnosis.Nevertheless, this table does not show whether Anakin presents sufficient criteria for a BPD diagnosis.Table2presents the nine BPD criteria, examples representing each (when applicable), and our conclusion regarding their presence in Anakin.

Table 1
Shared features between Borderline Personality Disorder and Bipolar Disorder in Anakin Skywalker's behaviors