A new study identifies specific brain regions involved in treatment response in bipolar disorder (BD) and borderline personality disorder (BPD), potentially paving the way for more targeted treatment.
In a meta-analysis of 34 studies that used neuroimaging to investigate changes in brain activation following psychotherapy and pharmacotherapy for BD and BPD, investigators found most brain regions showing abnormal activation in both conditions improved after treatment. In particular, changes in brain activity after psychotherapy were found primarily in the frontal areas, whereas pharmacotherapy largely altered the limbic areas.
"This study can help clinicians with clinical prediction of treatment efficacy between BD and BPD and clarify the neural mechanism of treatment for these two diseases," senior investigator Xiaoming Li, PhD, professor, Department of Medical Psychology, Anhui Medical University, Hefei, China, told Medscape Medical News.
"It may also contribute to the identification of more accurate neuroimaging biomarkers for treatment of the two disorders and to the finding of more effective therapy," Li said.
The study was published online March 27 in the Journal of Clinical Psychiatry.
Li called BDs and BPDs "difficult to diagnose and differentiate," noting that the comorbidity rate is "very high." Underestimating the boundary between BD and BPD "increases the risk of improper or harmful drug exposure," since mood stabilizing drugs are "considered to be the key therapeutic intervention for BD, while psychotherapy is the key treatment for BPD."
The "blurred boundary between BD and BPD is one of the reasons it is important to study the relationship between these two diseases," the authors say.
Previous studies comparing the relationship between BD and BPD "did not explore the similarities and differences in brain mechanisms between these two disorders after treatment," they point out.
Patients with BD have a different disease course and response to therapy, compared to patient with BPD patients. "Misdiagnosis may result in the patients receiving ineffective treatment, so it is particularly important to explore the neural mechanisms of the treatment of these two diseases," Li said.
To investigate, the researchers used activation likelihood estimation (ALE) — a technique that examines coordinates of neuroimaging data gleaned from published studies — after searching several databases from inception until June 2021.
This approach was used to "evaluate the similarities and differences in the activation of different brain regions in patients with BD and BPD after treatment with psychotherapy and drug therapy."
Studies were required to focus on patients with a clinical diagnosis of BD or BPD; neuroimaging studies using functional MRI; coordinates of the peak activations in the stereotactic space of the Montreal Neurologic Institute or Talairach; treatment (pharmacologic or psychological) for patients with BD or BPD; and results of changes in brain activation after treatment, relative to a before-treatment condition.
Of 1592 records, 34 studies (n = 912 subjects) met inclusion criteria and were selected and used in extracting the activation coordinates. The researchers extracted a total of 186 activity increase points and 90 activity decrease points. After combining these calculations, they found 12 increased activation clusters and 2 decreased activation clusters.
Of the studies, 23 focused on BD and 11 on BPD; 14 used psychotherapy, 18 used drug therapy, and 2 used a combination of both approaches.
Normalizing Activation Levels
Both treatments were associated with convergent activity increases and decreases in several brain regions: the anterior cingulate cortex, medial frontal gyrus, inferior frontal gyrus, cingulate gyrus, parahippocampal gyrus, and the posterior cingulate cortex.
The researchers then examined studies based on treatment method — psychotherapy or pharmacotherapy and the effect on the two disorders.
"After psychotherapy, the frontal lobe and temporal lobe were the primary brain regions in which activation changed, indicating a top-down effect of this therapy type, while after drug therapy, the limbic area was the region in which activation changed, indicating a 'bottom-up' effect," said Li.
Li cited previous research pointing to functional and structural abnormalities in both disorders — especially in the default mode network (DMN) and frontolimbic network.
In particular, alterations in the amygdala and the parahippocampal gyrus are reported more frequently in BPD than in BD, whereas dysfunctional frontolimbic brain regions seem to underlie the emotional dysfunction in BPD. Several studies have also associated the impulsivity of BD with dysfunctions in the interplay of cortical-limbic circuits.
Li said the study findings suggest "that treatment may change these brain activation levels by acting on the abnormal brain circuit, such as the DMN and the frontolimbic network so as to 'normalize' its activity and improve symptoms."
Specifically, brain regions with abnormally increased activation "showed decreased activation after treatment, and brain regions with abnormally decreased activation showed increased activation after treatment."
Discrete, Overlapping Mechanisms
Commenting for Medscape Medical News, Roger McIntyre, MD, professor of psychiatry and pharmacology, University of Toronto, Canada, and head of the Mood Disorders Psychopharmacology Unit, said the study "provides additional support for the underlying neurobiological signature of bipolar disorder and a commonly encountered co-occurring condition — borderline personality disorder — having both discrete yet overlapping mechanisms."
He found it interesting that "medications have a different principal target than psychosocial interventions, which has both academic and clinical implications."
"The academic implication is that we have reasons to believe that we will be in a position to parse the neurobiology of bipolar disorder or borderline personality disorder when we take an approach that isolates specific domains of psychopathology, which is what they [the authors] appear to be doing," said McIntyre, who wasn't associated with this research.
In addition, "from the clinical perspective, this provides a rationale for why we should be integrating pharmacotherapy with psychotherapy in people who have comorbid conditions like borderline personality disorder, which affects 20% of people living with bipolar disorder and 60% to 70% have borderline traits," he added.
The research was supported by the Anhui Natural Science Foundation and Grants for Scientific Research from Anhui Medical University. Li and co-authors declare no relevant financial relationships. McIntyre has received research grant support from CIHR/GACD/National Natural Science Foundation of China (NSFC) and the Milken Institute; speaker/consultation fees from Lundbeck, Janssen, Alkermes, Neumora Therapeutics, Boehringer Ingelheim, Sage, Biogen, Mitsubishi Tanabe, Purdue, Pfizer, Otsuka, Takeda, Neurocrine, Sunovion, Bausch Health, Axsome, Novo Nordisk, Kris, Sanofi, Eisai, Intra-Cellular, NewBridge Pharmaceuticals, Viatris, AbbVie, Atai Life Sciences. McIntyre is a CEO of Braxia Scientific Corp.
J Clin Psychiatry. Published online March 27, 2023. Abstract
Batya Swift Yasgur MA, LSW is a freelance writer with a counseling practice in Teaneck, NJ. She is a regular contributor to numerous medical publications, including Medscape and WebMD, and is the author of several consumer-oriented health books as well as Behind the Burqa: Our Lives in Afghanistan and How We Escaped to Freedom (the memoir of two brave Afghan sisters who told her their story).
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Cite this: Predicting BPD vs Bipolar Treatment Response: New Imaging Data - Medscape - Apr 18, 2023.