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Table 3 Double-blind placebo controlled trials of omega-3 fatty acids in schizophrenia.

From: Omega-3 fatty acids as treatments for mental illness: which disorder and which fatty acid?

Ref Jadad score Meds Age Gender Omega-3 fatty acid Prep. type Duration N Average baseline score Δ Statistical significance vs. placebo
3 5 100% 43 38% 2 g/day EPA Crude mixture 12 weeks 29 75 -4.1 Yes
    43 29% 2 g/day DHA Crude mixture 12 weeks 40 73 +2.2 No
3 5 0%1 35 40% 2 g/day EPA Crude mixture 12 weeks 26 75 -3.6 Yes
52 5 100% (typical) 39 54% 1 g/day EPA Ethyl ester 12 weeks 21 74 +7.0 No
    37 47% 2 g/day EPA Ethyl ester 12 weeks 17 75 +4.2 No
    38 57% 4 g/day EPA Ethyl ester 12 weeks 22 77 +2.5 No
   100% (atypical) 39 54% 1 g/day EPA Ethyl ester 12 weeks 23 76 +5.2 No
    37 47% 2 g/day EPA Ethyl ester 12 weeks 26 82 -0.9 No
    38 57% 4 g/day EPA Ethyl ester 12 weeks 23 81 +10.6 No
   100% (clozapine) 39 54% 1 g/day EPA Ethyl ester 12 weeks 16 79 -10.1 No
    37 47% 2 g/day EPA Ethyl ester 12 weeks 16 81 -17.8 Yes
    38 57% 4 g/day EPA Ethyl ester 12 weeks 13 74 -6.9 No
   100% (all meds) 39 54% 1 g/day EPA Ethyl ester 12 weeks 60 77 -1.02 No2
    37 47% 2 g/day EPA Ethyl ester 12 weeks 59 78 +5.42 No2
    38 57% 4 g/day EPA Ethyl ester 12 weeks 58 77 -3.72 No2
53 4 100% 40 39% 3 g/day EPA Ethyl ester 12 weeks 87 75 +2.0 No
        16 weeks 87   +1.0 No
56 3 100% 45 NS 3 g/day EPA Ethyl ester 9 weeks 40 75 -9.5 Yes
        12 weeks 40   -7.33 Yes
  1. Δ is refers to the change from baseline symptom scores for the omega-3 fatty acid group minus change from baseline scores for the placebo group. Jadad design quality scores can range from 0 to 5 with 5 being best. The symptom scale used in all the trials is the Positive and Negative Symptom Scale (PANSS). Zero is best for this scale hence a negative Δ value indicates an improvement over placebo. The average baseline score is the average of the omega-3 and placebo group scores at the start of the trial. Gen (gender) refers to the % of female participants in the trial. Meds refers to the percentage of trial participant who were in receipt of conventional medications for schizophrenia. Prep. type describes whether a crude oil mixture or a purified fatty acid was used. Notes: 1Although trial participants were not in receipt of medication at commencement, they were giving anit-psychotic medications as required during the trial. 2The primary outcome measure was stated by the authors to be 12 weeks, but this was not reported in the text; therefore this estimate is an approximation based on Figure 1 in Emsley and colleagues [56]. 3 Calculated from Tables 6 – 8 in Peet and Horrobin [52].