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Marine Omega-3 Fatty Acid Supplementation for Borderline Personality Disorder: A Meta-Analysis

Karaszewska D, Ingenhoven T, Mocking R (2021) Journal of Clinical Psychiatry 82(3) 20r13613 10.4088/JCP.20r13613  

Web URL: Read this and related articles on Psychiatrist



Several promising studies investigated marine omega-3 fatty acids (ie, fish oil) in borderline personality disorder (BPD), but overall effects remain unclear. The aim of this study was to obtain estimates of effectiveness of omega-3 fatty acids in BPD using meta-analysis, with a priori differentiation of affective, impulsive, and cognitive-perceptual symptom domains.

Data Sources: 

We performed a literature search in PubMed, EMBASE, PsycINFO, and MEDLINE, using terms related to BPD and omega-3 fatty acids. Publication date was not a restriction.

Study Selection: 

We included randomized controlled trials (RCTs) that compared omega-3 fatty acids to placebo or any active comparator and pooled data using meta-analysis. Five studies were included in the meta-analysis, describing 4 RCTs testing effects of omega-3 fatty acids in 137 patients with BPD or BPD-related behavior.

Data Extraction: 

Using a pre-piloted data extraction form, we obtained data including intervention dose, duration, and BPD symptom scale scores, differentiating affective, impulsive, and cognitive-perceptual symptom domains.


Random effects meta-analysis showed an overall significant decreasing effect of omega-3 fatty acids on overall BPD symptom severity (0.54 standardized difference in means [SDM]; 95% CI = 0.91 to 0.17; Z = 2.87; P = .0041), without heterogeneity (I2 = 0.00; Q = 2.63; P = .45).

A priori differentiation of relevant symptom domains showed significant effects on affect dysregulation (0.74 SDM; 95% CI = 1.21 to 0.27; Z = 3.11; P = .002) and impulsive behavior (0.45 SDM; 95% CI = 0.84 to 0.059; Z = 2.26; P = .024). However, effects on cognitive-perceptual symptoms did not reach the significance threshold.


Available data indicate that marine omega-3 fatty acids improve symptoms of BPD, particularly impulsive behavioral dyscontrol and affective dysregulation. Marine omega-3 fatty acids could be considered as add-on therapy.


Findings from this new meta-analysis support the use of dietary supplementation with the long-chain omega-3 fatty acids found in fish oils - but particularly EPA - as an add-on treatment for Borderline Personality Disorder.

It is almost 20 years since the very first published randomised controlled clinical trial showing that dietary supplementation with omega-3 fatty acids (specifically, the long-chain omega-3 EPA) could be of significant benefit in Borderline Personality Disorder,* reducing symptoms of both depression and impulsive or aggressive behaviours. See:

Despite those promising initial findings, his new systematic review identified only 4 published randomised controlled trials assessing the effect of omega-3 supplementation in BPD - involving a total of just 137 patients.

While this is clearly a small number, meta-analysis of these trials again showed that supplementation with omega-3 fatty acids reduced overall BPD symptoms, with a fairly impressive effect size of 0.54.  (p = .004)

(NB: A minimum effect size of 0.3 is usually needed for a treatment to be considered 'clinically meaningful' - and this is the typical effect size reported for either antidepressants or the best psychological treatments for major depression)

The researchers also evaluated the treatment effects separately for each of the three main BPD symptom domains — mood dysregulation, behavioral problems (such as impulsivity, aggression or self-harm), and cognitive / perceptual symptoms (such as dissociation or paranoid thoughts).

For mood dysregulation, the treatment effect size was 0.74 (p=0.002). This is in keeping with other evidence that long-chain omega-3 - and particularly EPA, as found in the trials reviewed here - is effective in reducing symptoms in clinical depression.
For impulsive behaviours, the treatment effect size was 0.45 (p=0.024), while for cognitive / perceptual symptoms the effect size did not reach statistical significance.

Importantly, no adverse side-effects were reported. Omega-3 are essential nutrients, and adequate supplies of both EPA and DHA (found in fish and seafood) are needed for healthy brain development and function, as well as for cardiovascular and immune health). However, these fats are seriously lacking from most modern, western-type diets.

In view of the safety and general health benefits of an increased dietary intake of these omega-3, the benefits for BPD symptoms shown by this meta-analysis, and the current lack of any effective pharmaceutical treatmentments for BPD, the researchers concluded that 'marine omega-3 fatty acids could be considered as add-on therapy'.


'Borderline Personality Disorder' (BPD) involves severe difficulties with emotional regulation that are longstanding, with intense mood swings that are both more frequent than those typical of bipolar disorder, and lack the same kind of periodicity. 

The instability of emotions and thoughts in BPD often leads to impulsive or reckless behaviour - particularly self-harm, substance abuse and aggressive behaviours - and unstable relationships. 

No medicines are licensed for BPD, so treatments primarily involve some form of psychotherapy. Good results can be achieved via specialist therapies of this kind (most notably Dialectical Behaviour Therapy, delivered by practitioners experienced in BPD) although these are not always easy to access.

More information on BPD and its treatment can be found via the NHS website.

And for further information for families and individuals affected by BPD, see The National Education Alliance for Borderline Personality Disorder