Omega-3 Treatment of Childhood Depression: A Controlled, Double-Blind Pilot Study

Psychiatrists at Ben Gurion University, Israel, studied successfully the efficacy of fish oil supplementation for children´s major depression. The report appeared in the June issue of the American Journal of Psychiatry which included two other reports on omega-3´s in psychiaty.

Abstract

The authors state that major depressive disorder is a common and recurrent disorder in children and that it is frequently accompanied by poor psychosocial outcome, comorbid conditions, and high risk of suicide and substance abuse, indicating the need for treatment. The prevalence of major depressive disorder is estimated to be approximately 2%–4% in children. However, the efficacy of biological treatment of prepubertal childhood depression is almost unknown. As the authors have found E-EPA to be effective in adult depression as an add-on therapy, they performed a controlled study with fish oil in childhood depression.

They supplemented with fish oil or placebo for 16 weeks 28 children, aged 6 to 12 years, referred to the depression clinic at the Schneider Children’s Medical Center of Israel or the Child Psychiatry Clinic of the Beer-Sheva Mental Health Center.

Ratings were made at baseline and at 2, 4, 8, 12, and 16 weeks using the Childhood Depression Rating Scale (CDRS), Childhood Depression Inventory (CDI), and Clinical Global Impression (CGI). The CDRS and CGI are clinician rated, whereas the CDI is self-rated by the child-patient at each visit.

The children received two 500 mg or one 1,000 mg capsule daily, depending on their ability to swallow a larger capsule. This was chosen as one-half of the adult dose used in our previous study. Placebo for the 500 mg capsule was olive oil containing no omega-3 fatty acids. Placebo for 1,000 mg capsules was safflower oil. The 1,000 mg active capsules contained 400 mg EPA and 200 mg DHA per 1,000 mg capsule. The 500 mg active capsules contained 190 mg EPA and 90 mg DHA per 500 mg capsule. Active and placebo capsules were identical in shape, markings, and appearance except for a slight difference in tone of internal color, which could be distinguished only by an experienced observer familiar with both types of capsules and able to compare them simultaneously.

Twenty children (10 verum and 10 placebo) completed at least 1 month’s ratings and were included in the data analysis. Of the eight who dropped out before 1 month, five were on placebo and three were on omega-3. There were seven boys and three girls in the placebo group and eight boys and two girls in the omega-3 group. Mean age in the omega-3 group was 10.0 (range: 8−12.0) and 10.3 in the placebo group (range: 8−12.5). Children had been depressed for a mean of 3.5 (SD=1.3) months in the omega-3 group and 3.3 (SD=1.6) months in the placebo group. This was a first depressive episode in all cases. In the omega-3 group, there were two children with comorbid attention deficit hyperactivity disorder, one with obsessive-compulsive disorder, one with separation anxiety, one with dysthymia, and one with chronic tics. In the placebo group, there were three children with attention deficit hyperactivity disorder, one with panic disorder, one with separation anxiety, and two with dysthymia. Concurrent medications on stable dose for at least 6 months were two children on methylphenidate in the omega-3 group and three children in the placebo group.

Figure 1 shows the CDRS scores in the 20 patients who completed at least 1 month, with the last value carried forward. The effect of omega-3 is highly significant. Among the children on omega-3 treatment, seven out of 10 had a greater than 50% reduction in CDRS scores. Of those on placebo, zero out of 10 had a greater than 50% reduction in CDRS scores (p=0.003, Fisher’s exact test). Four out of 10 children in the omega-3 group met the remission criteria of Emslie and colleagues of a CDRS score <29 at study exit; no subject in the placebo group met this criteria (p= NS). CGI results were also highly significant. There was a significant main effect of treatment and time The omega-3 group and the placebo group were significantly different at week 8, week 12 and week 16. No clinically relevant side effects were reported.

The authors discuss the very small placebo effect and state that they observed similar findings in a previous study of omega-3 in adult depression. The previous study in adults used ethyl-EPA (E-EPA), the precursor of docosahexaenoic acid while the present study used a combination of EPA and DHA that is commonly available as an over-thecounter preparation. The authors stress that not all studies of omega-3 fatty acids (using DHA) in depression in adults have been positive. The reasons for this discrepancy are unclear, but baseline dietary differences in different populations may be involved. The present study is the first, to our knowledge, of omega-3 treatment in prepubertal childhood depression.

Nemets H, Nemets B, Apter A, Bracha Z, Melmaker RH. American Journal of Psychiatry 2006;163:1098-1100 [Abstract]

The same issue of Am J Psychiatr (2006; June) published two other reports on omega-3´s in psychiatry.

Gordon Parker, Neville A. Gibson, Heather Brotchie, Gabriella Heruc, Anne-Marie Rees, and Dusan Hadzi-Pavlovic Omega-3 Fatty Acids and Mood Disorders American Journal of Psychiatry 2006 163: 969-978. [Abstract]

M. Elizabeth Sublette, Joseph R. Hibbeln, Hanga Galfalvy, Maria A. Oquendo, and J. John Mann. Omega-3 Polyunsaturated Essential Fatty Acid Status as a Predictor of Future Suicide Risk. Am J Psychiatry 2006 163: 1100-1102. [Abstract]