• Detailed clinical assessment with collateral info needed 
• Symptomatic longitudinal profile must be considered prior to definitive diagnosis

A detailed clinical assessment comprised of collateral information is necessary to diagnose adolescents with affective instability while the mental health professional needs to consider the symptomatic longitudinal profile of a related patient before making a definitive diagnosis.

These points were made in a brief report on the ‘Diagnostic overlap between adolescent affective instability in borderline personality and juvenile bipolar disorder in Sri Lanka’ which was authored by M. Chandradasa, W.K.T.R. Fernando and K.A.L.A. Kuruppuarachchi (all three attached to the Kelaniya University's Medical Faculty's Psychiatry Department and the same University’s Psychiatry Unit at the Colombo North Teaching Hospital in Ragama), and published in the Sri Lanka Journal of Psychiatry's 10th Volume's Second Issue in December, 2019.

Borderline personality disorder is, as defined in the American Psychiatric Association's ‘Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition (DSM 5)’, a psychiatric disorder that is known to have a pervasive pattern of instability in affect regulation, problems in interpersonal relationships, deficits in impulse control, and an unstable self image. This personality disorder has led to concerns for the mental health services due to, according to M. Kaess, R. Brunner and A. Chanen's ‘Borderline personality disorder in adolescence’, D.W. Black, N. Blum, B. Pfohl and N. Hale's ‘Suicidal behaviour in borderline personality disorder: Prevalence, risk factors, prediction, and prevention’ and F. Leichsenring, E. Leibing, J. Kruse, A.S. New and F. Leweke's ‘Borderline personality disorder’, the associated high risk of self harm and suicide, impairment in psychosocial functioning, and a high burden on the families. N. Perera's ‘Prevalence of personality disorders in late adolescents with drug abuse’ found a 35% prevalence of borderline personality disorder in young substance users in individual rehabilitation centres in Sri Lanka. Further, M. Chandradasa, L. Champika, S. Mendis and N. Fernando's ‘Female offenders with psychiatric disorders in Sri Lanka’ diagnosed borderline personality disorder among 8% of the participants admitted to a forensic in-patient unit. 

Bipolar disorder is, per J. Hunt, C.M. Schwarz, P. Nye and E. Frazier's ‘Is there a bipolar prodrome (an early symptom indicating the onset of a disease or illness) among children and adolescents?", a mood disorder that is known to impair youth behaviour, family, and social functioning. The impact of bipolar disorder is higher on the person and the families due to the relapsing nature of the illness. P.K. Arachchige, K.M. Senevirathne, V.P. Eranga, P.L. Fernando, M.U. Peiris, K.A. Kuruppuarachchi and S.S. Williams' ‘A naturalistic observational study of patients with bipolar affective disorder from two tertiary care hospitals in Sri Lanka’ reports that more than half of the patients experience their first relapse of bipolar disorder within two to five years from the onset of the illness. Family members of the patient are at risk at times, as manic relapses may be associated with violent behaviour. M. Chandradasa, L. Champika and T.N. Rajapakse's ‘Association of family history of bipolar disorder with the risk of violence in in-patient mania: A cohort study’ revealed significantly higher rates of unemployment, the harmful use of alcohol, the absence of confiding relationships and violence related risk scores in participants with a positive family history of bipolar disorder.

The World Health Organisation's ‘Adolescent health and development’ defines adolescents as individuals between the ages of 10-19 years. Both borderline personality disorder and bipolar disorder could begin to show initial symptoms during this period of transition. Of these symptoms, affective instability is, as noted in J. Richetin, E. Preti, G. Costantini and C. De Panfilis's ‘The centrality of affective instability and identity in borderline personality disorder: Evidence from network analysis", considered t                                                                                o be a central feature of borderline personality disorder. Affective instability is a psychopathological feature seen with a complex construct that includes primary and secondary emotions. Each emotion, as explained in S.M. Renaud and C. Zacchia's ‘Toward a definition of affective instability’, has its characteristics, amplitude, and duration. There is a rapid shift from the neutral affect to an intense affect, and this is associated with a dysfunctional modulation of emotions. This clinical phenomenon is often confused with mood lability (something that is constantly undergoing change or is likely to undergo change), as in bipolar disorders. Affective instability is, as elaborated in P.S. Santangelo, J. Koenig, T.D. Kockler, M. Eid, J. Holtmann, S. Koudela-Hamila, P. Parzer, F. Resch, M. Bohus, M. Kaess and U.W. Ebner-Priemer's ‘Affective instability across the lifespan in borderline personality disorder - A cross-sectional electronic diary study, the highest in persons with borderline personality disorder at a young age, and declines with ageing. Apart from borderline personality disorder, affective instability is seen in bipolar disorder. However, affective instability in borderline personality disorder is more associated with interpersonal events than in bipolar disorder, per D.B. Reich, M.C. Zanarini, C.J. Hopwood, K.M. Thomas and G.M. Fitzmaurice's ‘Comparison of affective instability in borderline personality disorder and bipolar disorder using a self report measure’.

Personality disorder vs. bipolar 

Differentiating borderline personality disorder from bipolar disorder in young people, as emphasised in E.d. Giacomo, F. Aspesi, M. Fotiadou, A. Arntz, E. Aguglia, L. Barone, S. Bellino, B. Carpiniello, F. Colmegna, M. Lazzari, L. Lorettu, F. Pinna, A. Sicaro, M.S. Signorelli and M. Clerici's ‘Un-blending borderline personality and bipolar disorders’, is a clinical challenge due to the presence of overlapping symptoms such as impulsivity, emotional and affective instability, irritability and sexual arousal. Because of these overlapping symptoms, there is a claim that borderline personality disorder and bipolar disorder lie in a singular spectrum. However, H. Yu, Y-J. Meng, X-J. Li, C. Zhang, S. Liang, M-L. Li, Z. Li, W. Guo, Q. Wang, W. Deng, X. Ma, J. Coid and T. Li's ‘Common and distinct patterns of grey matter (makes up the outer-most layer of the brain, and gets its grey tone from a high concentration of neuronal cell bodies) alterations in borderline personality disorder and bipolar disorder: Voxel based meta analysis’, which was a neuro-imaging study, revealed that they have distinct grey matter volume and grey matter density patterns and that borderline personality disorder showed decreased grey matter volume and grey matter density in the bilateral medial prefrontal cortex (a cortical [relating to the outer layer of the cerebrum {the principal and most anterior part of the brain in vertebrates, located in the front area of the skull and consisting of two hemispheres, left and right, separated by a fissure, and which is responsible for the integration of complex sensory and neural functions and the initiation and coordination of voluntary activity in the body}] region with different cell types and projections, and which integrates information from numerous input structures and converges updated information to output structures through the connections with other cortical and sub-cortical areas), the bilateral amygdala (a small part of the brain which is a major processing centre for emotions and also links emotions to many other brain related abilities, especially memories, learning and the senses), and the right parahippocampal gyrus (a grey matter cortical region of the brain that surrounds the hippocampus [a complex brain structure embedded deep into temporal lobe and which has a major role in learning and memory] and is part of the limbic system [the part of the brain involved in our behavioural and emotional responses, especially when it comes to behaviours we need for survival: feeding, reproduction and caring for our young, and the fight or flight responses], and which plays an important role in memory encoding and retrieval), while bipolar disorder was associated with decreases in the bilateral medial orbital frontal cortex (a prefrontal cortex region in the frontal lobes of the brain which is involved in the cognitive process of decision making), the right insula (a portion of the cerebral cortex folded deep within the lateral sulcus [the fissure separating the temporal lobe from the parietal {a key part of one’s understanding of the world around one and which processes the sense of touch and assembles input from the other senses into a form that one can use and also helps one understand where one is in relation to other things that one’s senses are picking up around one} and frontal lobes] within each hemisphere of the mammalian brain, and the insulae are believed to be involved in consciousness and play a role in diverse functions usually linked to emotion or the regulation of the body's homeostasis) and the right thalamus (an egg shaped structure in the middle of the brain, that is known as a relay station of all incoming motor [movement] and sensory information [hearing, taste, sight and touch, but not smell] from the body to the brain).

Complex presentations of affective instability in adolescence could be misdiagnosed and could deprive the patient of evidence based treatment. This could be further complicated in Sri Lanka due to, per M. Chandradasa and K.A. Kuruppuarachchi's ‘Child and youth mental health in post-war Sri Lanka’ and M. Chandradasa and L. Champika's ‘Sub-specialisation in postgraduate psychiatry and implications for a resource limited specialised child and adolescent mental health service’, limited child and adolescent mental health services. 

Chandradasa et al. described three adolescents with affective instability, treated for bipolar disorder.

Case one 

A 15-year-old girl presented with a four week history of school refusal. Her parents reported that she had frequent intense arguments with them about non-significant daily matters. On further assessment, there was a history suggestive of poor impulse control, leading to verbal and physical aggression towards the family members and three episodes of deliberate self harm by self cutting during the past three years. She stated that she had a feeling of emptiness within her despite being supported by her family. Clinical observations and collateral information revealed that she had rapid mood changes, ranging from brief dysphoria to marked irritability. At times, there were disinhibited behaviours, with her approaching adult male strangers. She was an adoptee, had been exposed to violence in early life and was noticed to have a difficult temperament since early childhood, with frequent tantrums and frustration intolerance. Recently, she had been seen by a psychiatrist and had been commenced on lithium carbonate (an inorganic compound, the lithium salt of carbonic acid is a white salt which is an essential medicine for its efficacy in the treatment of mood disorders such as bipolar disorder) as for bipolar disorder. Her symptomatology did not change after being treated with lithium for six months.

Case two 

A 16-year-old boy presented with episodes of short lasting anger, irritability and truancy in the context of frequent interpersonal conflicts with his school peers and parents. He often idealised some of his school colleagues, labelling them as ‘true friends’. However, almost always, these friendships ended with bitter conflict and devaluation. He frequently threatened to commit suicide when his parents did not meet his demands for expensive mobile phones. He was suspicious that his peers at school were jealous of him and were plotting against him. However, these beliefs were transient and not firmly held. Despite this belief, he wanted to be admired by his peers and felt distressed when they ignored him. According to his parents, he had been exposed to severe emotional abuse and verbal harassment by a teacher when he was in primary school. This adolescent had been diagnosed with bipolar disorder and was on lithium and an atypical antipsychotic used to treat schizophrenia and bipolar disorder for 12 months, with no noticeable improvement in his mental state.

Case three 

The third adolescent was a 16-year-old girl who presented with repeated acts of deliberate self harm for one year by overdosing on paracetamol (an analgesic and antipyretic [prevent or reduce fever] agent used to treat fever and mild to moderate pain) tablets. All these episodes of self harm followed conflicts with her current and ex-boyfriends and her attempts to re-establish these relationships. These incidents happened against a background of many relationship break-ups and with severe distress, including verbal, physical and online aggression towards those close to her. She also had brief episodes of affective instability ranging from dysphoria (a mental state in which a person has a profound sense of unease or dissatisfaction) to irritability. In addition to short lasting episodes of excessive anxiety, she had a long standing sense of disconnection and loneliness. She had been diagnosed with bipolar disorder and had been treated with sodium valproate (used to treat epilepsy and bipolar disorder and  occasionally to prevent migraine headaches) and an atypical antipsychotic primarily used to treat schizophrenia and bipolar disorder for six months with no clinical improvement.

All three adolescents were followed up for more than 12 months and were subsequently diagnosed to have borderline personality disorder according to the DSM 5.

Discussion

These case reports demonstrate how affective instability could present in adolescence. The mood changes could easily suggest a clinical picture of a mood disorder. Borderline personality disorder may have substantial phenomenological overlap with bipolar disorder, as mood lability and impulsivity are common in both the conditions. For a diagnosis of bipolar disorder, the symptoms must represent a distinct episode, and the effect change should be clearly over the baseline. It is recommended that a diagnosis of borderline personality disorder should not be made during an untreated mood episode.

The described adolescents had a prominent irritable mood. In a Brazilian study, 92% of the patients with juvenile bipolar disorder under the age of 15 years had an irritable mood during a relapse. P.A. Geoffroy, R. Jardri, B. Etain, P. Thomas and B. Rolland's ‘Bipolar disorder in children and adolescents: A difficult diagnosis’ reports that juvenile bipolar disorder is a difficult diagnosis to make as the primary symptoms vary much from the typical disorder in adulthood and since the euphoric mood is rare in juvenile bipolar disorder while aggressiveness, irritability, rapid cycling, violent outbursts and a chronic course of symptoms are more prevalent. Even though the three reported adolescents presented with prominent irritability, the carefully taken longitudinal clinical history did not demonstrate an episodic affective pattern and features of borderline personality disorder became evident with collateral information.

The adolescents described herewith had instability in their affect. Their effect changed from dysphoric spells to irritability within a short period. Borderline personality disorder is frequently confused with bipolar disorder type two because of their symptomatic overlap. J. Paris and D.W. Black's ‘Borderline personality disorder and bipolar disorder: What is the difference and why does it matter?’ states that affective instability is a prominent feature of each. However, the pattern is entirely different. Borderline personality disorder is characterised by transient mood shifts induced by interpersonal stressors, such as in the described histories, whereas in bipolar disorder, there are sustained mood changes. All three of the adolescents described had been prescribed mood stabilisers and/or antipsychotics. Likewise, a hasty diagnosis in an adolescent with affective instability could deprive the patient of potentially effective treatment, such as psychotherapy for borderline personality disorder and also expose them to unwanted psychopharmacological effects.

The three adolescents in question had been prescribed mood stabilisers as for bipolar disorder. C.J. Ruggero, M. Zimmerman, I. Chelminski and D. Young's ‘Borderline personality disorder and the misdiagnosis of bipolar disorder’ found that nearly 40% of the patients with borderline personality disorder had been previously misdiagnosed as having bipolar disorder. Nevertheless, M. Zimmerman and T.A. Morgan's ‘The relationship between borderline personality disorder and bipolar disorder’ reported that approximately 10% of the patients with borderline personality disorder had co-morbid bipolar disorder one while another 10% had bipolar disorder two disorders (the main difference between bipolar I and bipolar II disorders is in the severity of the manic episodes where a person with bipolar I will experience an episode of mania, while a person with bipolar II will experience a hypomanic episode [a period less severe than a full manic episode] and a person with bipolar I may or may not experience a depressive episode, while someone with bipolar II will experience a major depressive episode). Two of the adolescents reported histories of childhood adversities and early life stress in the form of emotional abuse and neglect, which are, as elaborated in A.K. Mazer, A.J. Cleare, A.H. Young and M.F. Juruena's ‘Bipolar affective disorder and borderline personality disorder: Differentiation based on the history of early life stress and psycho-neuroendocrine measures’, more common in borderline personality disorder compared to bipolar disorder.