Commentary on chronic mood instability: Bipolar, borderline or both?

Abstract

The paper "Chronic mood instability: Bipolar, borderline or both? 1 " deserves being discussed, as the debate concerning the differential diagnosis between BPD and BD is often limited to a battle between "psychological" and "biological" factions. The growing body of literature dealing with the concepts of neurodevelopmental emotional dysregulation and cyclothymia seems to show a wide area of overlap among all these conditions, simultaneously tending to bit by bit reduce the clinical relevance of the construct of BPD.The idea of a bipolar disorder clearly separated from BPD, due to episodic course and clear-cut mood states, together with the response to pharmacological treatments is rather limited and can only be applied to a small proportion of BDs, type 1 or 2, with a "typical" episodic pattern. The case presented by the PROMAN group is thus paradigmatic and is worth discussed.The presence of very early onset sleep disturbances, emotional outbursts etc would require further investigation as those symptoms might suggest the presence of a neurodevelopmental emotional dysregulation, probably belonging to the ADHD spectrum. Indeed, one of the diagnoses the patient received during her own psychiatric history was ADHD. Her family history, accounting for several cases of depression, suicidality, alcohol abuse and other unspecified conditions, which also supports such argument. ADHD shows a relatively high prevalence among children of parents with BD, thus sharing with BD itself a strong familial-genetic background, together with a chronic course and lifelong impairment.ADHD and the related emotional dysregulation in childhood is often a precursor of BPD and BD in adulthood. A common clinical pathway consists of an early observation of ADHD in children, who then develop BPD in adolescence and finally display BD episodes as they reach adulthood. Emotional dysregulation and impulsivity are dimensions belonging to both ADHD and bipolar spectrum disorders and in many cases a differential diagnosis is not easily formulated.Indeed, a cyclothymic temperament was found as highly prevalent as 71% in a sample of 586 clinically diagnosed Norwegian adult ADHD patients. 2. Such temperamental disposition identifies a subgroup of more severely impaired subjects, possibly reflecting an underlying affective and emotional instability with a pathophysiology closely related to the early onset bipolar spectrum disorders.The influence of cyclothymic temperament and cyclothymia on a more complex and atypical clinical presentation of BD may further tangle the issue of the BPD comorbidity/misdiagnosis. Taken into account that some constructs such as affective temperaments and neurodevelopmental emotional dysregulation are largely overlapping, we can consistently suppose that they can also determine peculiar psychological and psychopathological features, which can often overlap with BPD criteria. For example, exaggerated emotional and mood reactivity, impulsivity and mood instability, even though commonly neglected in favour of a focus on mood s...