Short Communication

European Journal of Clinical Nutrition (2009) 63, 1037–1040; doi:10.1038/ejcn.2008.81; published online 21 January 2009

Reduced mania and depression in juvenile bipolar disorder associated with long-chain ω-3 polyunsaturated fatty acid supplementation

Contributors: EHC assisted with design of the study and data collection, was responsible for data analysis and interpretation and drafted the paper; TLH, SJH and CJK collected data and assisted with interpretation and revision of the paper; MLG assisted with interpretation and revision of the paper and PLH assisted with data analysis and interpretation and revision of the paper. All authors contributed to the intellectual content and approved the final version of the paper.

E H Clayton1,2, T L Hanstock3,4,5, S J Hirneth3, C J Kable3, M L Garg2 and P L Hazell6,7

  1. 1NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Wagga Wagga, New South Wales, Australia
  2. 2Nutraceuticals Research Group, University of Newcastle, Callaghan, New South Wales, Australia
  3. 3The Bipolar Program, Hunter New England Area Health Service, Newcastle, New South Wales, Australia
  4. 4School of Psychology, University of Newcastle, Callaghan, New South Wales, Australia
  5. 5School of Psychology, University of New England, New South Wales, Australia
  6. 6Discipline of Psychological Medicine, Concord Clinical School, University of Sydney, New South Wales, Australia
  7. 7Discipline of Psychiatry, School of Medical Practice and Population Health, University of Newcastle, Callaghan, New South Wales, Australia

Correspondence: Dr EH Clayton, NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Pine Gully Road, Wagga Wagga, New South Wales 2650, Australia. E-mail: edward.clayton@dpi.nsw.gov.au

Received 18 August 2008; Revised 30 November 2008; Accepted 2 December 2008; Published online 21 January 2009.

Top

Abstract

Long-chain ω-3 polyunsaturated fatty acid (LCn-3PUFA) supplementation may improve symptoms of depression in children and bipolar disorder (BD) in adults. No studies have examined the effectiveness of LCn-3PUFA supplementation in the treatment of mania and depression in juvenile BD (JBD) when given as an adjunct to standard pharmacological treatment. Eighteen children and adolescents with JBD received supplements containing 360mg per day eicosapentaenoic acid (EPA) and 1560mg per day docosahexaenoic acid (DHA) for 6 weeks in an open-label study. Intake and fasting red blood cell (RBC) LCn-3PUFA, mania, depression and global function were assessed before and after supplementation. RBC EPA and DHA were significantly higher following supplementation. Clinician ratings of mania and depression were significantly lower and global functioning significantly higher after supplementation. Parent ratings of internalizing and externalizing behaviours were also significantly lower following supplementation. A larger randomized controlled trial appears warranted in this participant population.

Keywords:

ω-3, EPA, DHA, children and adolescents, psychiatry, juvenile bipolar disorder

Top

Introduction

The diagnosis of juvenile bipolar disorder (JBD) in children and adolescents is becoming increasingly accepted. The lifetime prevalence of JBD (approximately 1–2%) is similar to adults (Lewinsohn et al., 2000). The use of first-line mood-stabilizing medications, such as lithium and valproate, has been associated with adverse effects including gastrointestinal upset, thyroid effects, weight gain and increased triglycerides (Wozniak et al., 2007), leading to impaired quality of life and decreased medication compliancy. Safer and alternative treatments improving functioning or decreased requirements for standard mood-stabilizing medications are needed.

Supplementation with long-chain ω-3 polyunsaturated fatty acids (LCn-3PUFA) may improve symptoms of bipolar disorder (BD) in adults (Stoll et al., 1999) and depression in children (Nemets et al., 2006) when given as an adjunct to standard pharmacotherapy and may improve symptoms of mania in young children with BD when given as monotherapy (Wozniak et al., 2007). No studies have examined the effects of LCn-3PUFA supplements in the treatment of mania and depression in JBD when given as an adjunct to standard pharmacotherapy.

Top

Methods

A total of 18 participants (12 female, mean age=16.1±0.81 years; 6 male, mean age=13.0±1.06 years) with JBD received three 1000mg capsules containing tuna oil twice a day for 6 weeks in an open-label manner. Capsules contained 60mg/g eicosapentaenoic acid (EPA) and 260mg/g docosahexaenoic acid (DHA) and participants received a total dose of 360mg per day EPA and 1560mg per day DHA.

Participants were included in the study, if they met diagnostic criteria for BD I (n=7), BD II (n=6) or BD not otherwise specified (n=5) as specified in the Diagnostic and Statistical Manual of Mental Disorders, fourth edn, Text Revision and were prescribed mood-stabilizing medication (lithium=9, valproate=7 and quetiapine=2). The mean time from diagnosis to study enrolment was 1.6±0.3 years and 10 participants had at least one co-morbid diagnosis including psychosis, attention-deficit hyperactivity disorder or generalized anxiety disorder. Several participants received other medication in addition to a primary mood-stabilizer, with the most common being risperidone, dexamphetamine and selective serotonin re-uptake inhibitors. Details of inclusion and exclusion criteria have been described previously (Clayton et al., 2008). Participants had not taken LCn-3PUFA supplements within the previous 12 weeks and were not receiving any medications that affected lipid metabolism or blood coagulation.

Symptoms of mania (Young Mania Rating Scale, YMRS), depression (Hamilton Depression Rating Scale, HAM-D) and global functioning (Global Assessment Scale for Children, C-GAS) were assessed by clinicians, and internalizing and externalizing behaviour (Child Behaviour Checklist—Parent Report, CBCL-PR) were assessed by parents before and after supplementation. Fasting blood samples were collected at each assessment and red blood cells (RBCs) were separated from plasma for analysis of fatty acids using gas chromatography. Details of the assessment of mood, behaviour and RBC fatty acids have been described previously (Clayton et al., 2008).

All procedures were approved by the Hunter New England Area and University of Newcastle Human Research Ethics Committees. Parents/guardians gave written informed consent before the study. The study was registered with the Australian Clinical Trials Registry (www.actr.org.au) ACTRN: ACTRN012606000440527.

Changes in measures were analysed by repeated measures analysis using the MIXED Model procedure in the SAS program (Clayton et al., 2008). Percentage changes in psychological measures were correlated with baseline measures and changes in RBC LCn-3PUFA by Pearson correlation. Behaviour ratings could not be collected from one participant and RBCs could not be isolated from another participant after supplementation.

Top

Results

Three participants withdrew during the study due to gastrointestinal disturbance (including bloating, increased flatulence and cramping). Supplement compliance (estimated by capsule count-back and interview with participants and parents/guardians) was 84.8±4.1% for participants who completed the study. RBC EPA and DHA increased following supplementation (Figure 1). The ω-3 index (RBC EPA+DHA%, Harris, 2007) increased from 4.2±2.1 to 7.8±1.9.

Figure 1.
Figure 1 - Unfortunately we are unable to provide accessible alternative text for this. If you require assistance to access this image, please contact help@nature.com or the author

Change in red blood cell (RBC) eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) as a percentage of total fatty acids in participants with juvenile bipolar disorder (JBD) before (shaded bars) and after (unshaded bars) the consumption of 360mg per day EPA and 1560mg per day DHA for 6 weeks. Data are least-squares means±standard error of the least-squares means.

Full figure and legend (40K)

Clinician ratings of mania and depression were significantly lower and global functioning significantly higher following supplementation (Table 1). Parent ratings of internalizing and externalizing behaviours were also significantly improved after treatment. Following a secondary intention-to-treat analysis using the last observation carried forward procedure, symptom change over time was still significant (data not shown).


Correlational analyses revealed a positive association between participant age and improvement in parent ratings of internalizing symptoms (r=0.59, P=0.045) and number of years between diagnosis and study enrolment and improvement in parent ratings of externalizing symptoms (r=0.56, P=0.046). Change in parent rated externalizing symptoms was diminished when participants received antipsychotic medication directed to agitation or aggression (n=3) compared with all other participants (n=11, symptom change=2.2±3.9 versus −9.6±2.2%, F=7.00, P=0.023). Changes in mood or behaviour were not significantly related to gender, primary diagnosis, mood-stabilizing medication or changes in RBC LCn-3PUFA.

Top

Discussion

Although improvements in mania in this study did not reach 50%, indicating a relatively small clinical response, depression change was greater than 50%. Forty percent of participants also had ‘Much’ or ‘Very much’ improved symptoms according to the Clinical Global Improvements scale, similar to LCn-3PUFA supplementation as monotherapy (Wozniak et al., 2007). Current changes were in addition to improvements that may have occurred with previous pharmacological treatment, as participants were stabilized on their usual medication for at least 6 weeks before the study. Parent ratings of internalizing and externalizing behaviour on the CBCL also improved following supplementation, similar to research with aggression (Itomura et al., 2005) and, were significantly related to age and time between diagnosis and study enrolment, respectively, which may be indicative of spontaneous improvement rather than a specific response to LCn-3PUFA supplementation. Changes in symptoms, however, were not significantly correlated to changes in RBC LCn-3PUFA. These findings should be interpreted with caution, however, owing to the small sample size.

Although the direct link between LCn-3PUFA and decreases in mania and depression cannot be elucidated from the current open-label design, supplementation significantly increased EPA and DHA in RBC membranes. EPA and DHA are selectively incorporated into the phospholipid fraction of RBC membranes (Galloway et al., 1985) and, as neurotransmitter receptors are affected by the fluidity of phospholipid membranes, receptor ‘function’ could be changed in 6 weeks following LCn-3PUFA supplementation. Increased membrane fluidity following LCn-3PUFA supplementation is associated with a general dampening of signal transduction pathways. These and other mechanisms linking LCn-3PUFA supplementation with improvement in BD have been reviewed previously (Clayton et al., 2007).

LCn-3PUFA supplementation in conjunction with standard pharmacotherapy may lead to additive improvements in membrane function, as lithium and valproate treatment is associated with decreased AA turnover without altering DHA turnover (Chang et al., 2001). Although symptom improvement in this study was not related to primary mood-stabilizing medication, changes in parent rated externalizing symptoms were diminished when participants without a co-morbid diagnosis of psychosis received antipsychotic medication. Further studies should determine whether improvements are consistent for different medications or whether medication dose could be decreased to reduce side effects, while maintaining similar symptom improvement.

There are obvious limitations to conducting an open-label study, including a lack of blinding and clinician and parent bias. Therefore, the improvement in symptoms in this study may be due to factors other than LCn-3PUFA. Despite these limitations, given the improved RBC LCn-3PUFA and reduced symptoms of JBD, together with previous results in adults, there appears to be enough evidence to warrant a large prospective randomized controlled trial in this participant population. Future studies should also consider using more concentrated forms of LCn-3PUFA to reduce the burden of taking the supplements in addition to standard medications.

Top

References

  1. Chang MC, Contreras MA, Rosenberger TA, Rintala JJ, Bell JM, Rapoport SI (2001). Chronic valproate treatment decreases the in vivo turnover of arachidonic acid in brain phospholipids: a possible common effect of mood stabilizers. J Neurochem 77, 796–803. | Article | PubMed | ISI | ChemPort |
  2. Clayton EH, Hanstock TL, Garg ML, Hazell PL (2007). Long-chain omega-3 polyunsaturated fatty acids in the treatment of psychiatric illnesses in children and adolescents. Acta Neuropsych 19, 92–103. | Article
  3. Clayton EH, Hanstock TL, Kable CJ, Hirneth SJ, Garg ML, Hazell PL (2008). Reduced long-chain omega-3 polyunsaturated fatty acids in the blood of children and adolescents with bipolar disorder compared to healthy controls. Lipids 43, 1031–1038. | Article | PubMed | ChemPort |
  4. Galloway JH, Cartwright IJ, Woodcock BE, Greaves M, Russell RG, Preston FE (1985). Effects of dietary fish oil supplementation on the fatty acid composition of the human platelet membrane: demonstration of selectivity in the incorporation of eicosapentaenoic acid into membrane phospholipid pools. Clin Sci 68, 449–454. | PubMed | ChemPort |
  5. Harris WS (2007). Omega-3 fatty acids and cardiovascular disease: a case for omega-3 index as a new risk factor. Pharmacol Res 55, 217–223. | Article | PubMed | ChemPort |
  6. Itomura M, Hamazaki K, Sawazaki S, Kobayashi M, Terasawa K, Watanabe S et al. (2005). The effect of fish oil on physical aggression in schoolchildren—a randomized, double-blind, placebo-controlled trial. J Nutr Biochem 16, 163–171. | Article | PubMed | ChemPort |
  7. Lewinsohn PM, Klein DN, Seeley JR (2000). Bipolar disorder during adolescence and young adulthood in a community sample. Bipolar Disord 2, 281–293. | Article | PubMed | ChemPort |
  8. Nemets H, Nemets B, Apter A, Bracha Z, Belmaker RH (2006). Omega-3 treatment of childhood depression: a controlled, double-blind pilot study. Am J Psychiatry 163, 1098–1100. | Article | PubMed
  9. Stoll AL, Severus WE, Freeman MP, Rueter S, Zboyan HA, Diamond E et al. (1999). Omega 3 fatty acids in bipolar disorder: a preliminary double-blind placebo-controlled trial. Arch Gen Psych 56, 407–412. | Article | ChemPort |
  10. Wozniak J, Biederman J, Mick E, Waxmonsky J, Hantsoo L, Best C et al. (2007). Omega-3 fatty acid monotherapy for pediatric bipolar disorder: a prospective open-label trial. Eur Neuropsychopharmacol 17, 440–447. | Article | PubMed | ChemPort |
Top

Acknowledgements

We thank Robert Blake and Melinda Phang for assistance in conducting LCn-3PUFA analyses. We also thank Sonney Morrison and Hunter Area Pathology Service staff for assistance with blood collection. We especially thank Robert Brown, Andrew Millgate and James Neal for constructive advice in the preparation of this paper. We thank Nu-Mega Ingredients Pty Ltd for in-kind donation of ω-3 capsules.

Top

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated

RESEARCH

Surrogate Endpoints for the Treatment of Venous Leg Ulcers

Journal of Investigative Dermatology Original Article

Inhibitory effects of omega-3 fatty acids on protein kinase C activity in vitro

Molecular Psychiatry Original Article

Extra navigation

.

natureevents

ADVERTISEMENT