Background There is ongoing debate on the nosological position of bipolar disorder (BD) and borderline personality disorder (BPD). Identifying the unique and shared risks, developmental pathways, and symptoms in emerging BD and BPD could help the field refine aetiological hypotheses and improve the prediction of the onset of these disorders. This study aimed to: (a) systematically synthesise the available evidence from systematic reviews (SRs) and meta-analyses (MAs) concerning environmental, psychosocial, biological, and clinical factors leading to the emergence of BD and BPD; (b) identify the main differences and common features between the two disorders to characterise their complex interplay and, (c) highlight remaining evidence gaps. Methods Data sources were; PubMed, PsychINFO, Embase, Cochrane, CINAHL, Medline, ISI Web of Science. Overlap of included SRs/MAs was assessed using the corrected covered area process. The methodological quality of each included SR and MA was assessed using the AMSTAR. Results 22 SRs and MAs involving 249 prospective studies met eligibility criteria. Results demonstrated that family history of psychopathology, affective instability, attention deficit hyperactivity disorder, anxiety disorders, depression, sleep disturbances, substance abuse, psychotic symptoms, suicidality, childhood adversity and temperament were common predisposing factors across both disorders. There are also distinct factors specific to emerging BD or BPD. Conclusions Prospective studies are required to increase our understanding of the development of BD and BPD onset and their complex interplay by concurrently examining multiple measures in BD and BPD at-risk populations.

Objective Recent research indicates that sleep problems in childhood precede the development of borderline personality disorder (BPD) symptoms, but the mechanisms by which sleep problems associate with BPD are still unknown. This narrative review aims to provide some potential explanations for how early sleep problems might associate with BPD. Methods We used the biosocial developmental model of BPD as a framework to discuss how sleep problems may associate with BPD. Articles were identified via PubMed and Embase, and papers published between January 1991 and April 2021 were extracted. Authors made a series of literature searches using the following keywords: Sleep problems, Insomnia, Nightmares, Hypothalamic–Pituitary–Adrenal Axis (HPA), Prefrontal Cortex, Family Psychopathology, Disrupted Attachment, Child Maltreatment, Impulsivity, Emotion Regulation, Internalizing, Externalizing, Rumination, Childhood, Adolescence, Young people. The inclusion criteria were published in peer-reviewed journals; human studies or reviews; published in English. The exclusion criteria were commentaries; abstracts from conferences; studies with animal samples. A total of 96 articles were included for the purpose of this review. Results The evidence from this review suggests that some biological factors and core features of BPD act as potential mechanisms mediating the associations between early sleep and subsequent BPD, while some family-related factors might constitute common risk factors for sleep problems and BPD. Conclusion The biosocial developmental model of BPD provides a plausible characterization of how sleep disruption might lead to subsequent BPD. Further research on new developmental and early intervention approaches to understand how sleep in early stages associates with BPD could have significant clinical impact on these patients and could inform targeted therapeutic interventions.

AimsThere is still an ongoing debate on the nosological position of Bipolar Disorder (BD) and Borderline Personality Disorder (BPD). Identifying the unique and shared risks and developmental pathways in emerging BD and BPD could help the field refine aetiological hypotheses of these disorders. The study aims were to systematically synthesise the available evidence from systematic reviews and meta-analyses concerning environmental, psychosocial, biological, and clinical factors leading to the emergence of BD and BPD to identify the main differences and common characteristics between the two disorders to characterise their complex interplay whilst highlighting remaining evidence gaps.MethodsA literature search was conducted PubMed, PsychINFO, EMBASE, Cochrane, CINAHL, MEDLINE, and ISI Web of Science as the data sources. 19 systematic reviews and meta-analyses involving 217 prospective studies met eligibility criteria.ResultsResults demonstrated that family history of psychopathology, affective instability, attention deficit hyperactivity disorder, anxiety disorders, depression, sleep disturbances, substance abuse, psychotic symptoms, suicidality, childhood adversity and temperament dimensions were common predisposing factors across both disorders. There are also many distinct variables that could be found early in the course of both disorders. Most of the factors should be considered as a general, nonspecific precursor signs and symptoms of both BPD and BD, apart from subsyndromal depression, subsyndromal hypomania, cyclothymia disorder, psychotic symptoms, age at onset of major depression and frequency and loading of affective symptoms.ConclusionAlthough the findings of this review may lead to support the view of BD and BPD as two distinct disorders, there is not sufficient data to either indicate that BD and BPD are separate nosological entities or that BPD should be considered as an extension of BD disorders. Future research is required to increase our understanding of the aetiology of BD and BPD onset and their complex interplay by conducting prospective studies which concurrently examine multiple measures including biological, environmental, psychosocial and clinical factors in BD and BPD at-risk populations. Large, multilevel data sets will enable deep phenotyping and distinguish pathophysiological pathways.

BackgroundMajor depressive disorder (MDD) is highly recurrent. Identifying risk factors for relapse in depression is essential to improve prevention plans and therapeutic outcomes. Personality traits and personality disorders are widely considered to impact outcomes in MDD. We aimed to evaluate the role of personality aspects in the risk of relapse and recurrence in MDD.MethodA PROSPERO-registered systematic review was conducted using Medline, Embase, PsycINFO, Web of Science and CINAHL as data sources, together with hand searching of four journals over the five years till 2022. There was independent abstract selection, quality assessment and data extraction from each study.ResultsTwenty two studies me t eligibility criteria involving 12,393 participants. Neurotic personality features are significantly associated with the risk of relapse and recurrence of depression, though the data is not uniform. There is some, though limited, evidence that borderline, obsessive-compulsive and dependent personality traits or disorders increase the risk for relapse in depression.LimitationsThe small number, in addition to the methodological heterogeneity of the included studies, did not allow further analysis, such as meta-analysis.ConclusionPeople with high neuroticism and dependent personality traits, borderline personality disorder or obsessive-compulsive personality disorder, compared to those without, may be at a higher risk of experiencing relapse or recurrence of MDD. Specific and targeted interventions may potentially reduce relapse and recurrence rates in these groups and could improve outcomes.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=235919, identifier: CRD42021235919.