Table 3.
Influence of bioactive lipids on cognition: Clinical studies of psychosis
| Study | Study aims and design | Sample | Variables | Results |
|---|---|---|---|---|
| G. P. Amminger et al. (115) |
Effect of n-3 PUFAs on rate of progression to first-episode psychotic disorder in young individuals with subclinical psychosis. Randomized, double- blind, placebo-controlled trial conducted from 2004 to 2007 |
81 individuals (13 – 25 yrs) at ultra- high risk for psychotic disorder |
IV: Random assignment (stratified by depression symptom score) to 12-week treatment trial of: (1) n-3 PUFA (1.2 g/day marine fish oil: 700 mg/day EPA, 480 mg/day DHA, 220 mg/day Other n-3 PUFAs including α-linolenic acid) vs. (2) placebo (coconut oil) DV: (1) Conversion to psychotic disorder determined by assessments conducted weekly (first 4 wks), and then at 8 and 12 wks, and 6 and 12 mos. (2) n-6 to n-3 ratio at baseline and 12- wks (fasting erythrocyte FA composition). |
A. Cumulative rates of conversion to psychotic disorder at 12 mos.: (1) 4.9% in n-3 PUFA group (2) 27.5% in placebo group. B. Compared to placebo, n-3 PUFAs improved functioning and reduced positive, negative, and general symptoms. C. For n-3 PUFA group, magnitude of change in n-6 to n-3 ratio from baseline to 12 wks was significantly associated with improvement in functioning between baseline and 12 wks. |
| G. E. Berger et al. (116) |
Effect of n-3 FA augmentation on efficacy and tolerability of treatment with antipsychotic drugs in patients with first-episode psychosis (FEP). Randomized, double- blind, placebo-controlled trial conducted from 2000 to 2003 |
80 FEP patients, which included 53 (76.8%) patients meeting criteria for non-affective psychosis |
IV: 12-weeks augmentation protocol: (1) 2 g/d ethyl-eicosapentaenoic acid (E-EPA) vs. (2) placebo oil Both E-EPA and placebo were added on to flexible doses of atypical antipsychotics (risperidone, olanzapine, or quetiapine). Additional medications allowed: benzodiazepines, chlorpromazine, zuclopenthixol, zolpidem, SSRIs. DV: Clinical assessments conducted at 5 time points (baseline and weeks 3, 6, 9, 12): (1) Symptom change scores and time to first response (2) Tolerability measures and cumulative antipsychotic dose |
A. No difference between E- EPA and placebo groups for symptom change scores at 12 weeks. B. Time to first response was shorter in patients diagnosed with non-affective psychosis and receiving E-EPA. C. Patients receiving E-EPA required lower doses of antipsychotic medications between weeks 4 and 6, compared to patients receiving placebo. D. Patients receiving E-EPA showed fewer extrapyramidal side effects during the initial 9 wks, compared to patients receiving placebo. |
| R. Condray et al. (43) |
Association between RBC membrane FAs and cognition in schizophrenia patients. Repeated measures design, double-blind placebo-replacement. |
37 chronic schizophrenia patients (mean age = 38 yrs) tested during haloperidol maintenance therapy (n=30) and placebo replacement (n=21). (Different n’s for medicated and placebo phases due to electrophysiological artifact.) |
DV: (1) RBC membrane FAs (venous blood draw after overnight fast) (2) Cognition: Electrophysiological measure of semantic memory (N400 component of event-related brain potential: N400- Unrelated minus N400-Related words) |
A. Semantic memory was associated with AA and total PUFAs for patients during unmedicated (placebo) phase: ↑ N400 semantic priming ↓ AA and Total PUFAs B. Semantic memory was not significantly associated with PUFAs for patients during haloperidol maintenance therapy. |
Abbreviations for Table 3: ↑, increase; ↓, decrease; AA, Arachidonic acid; DHA, Docosahexaenoic acid; DV, Dependent variable; EPA, Eicosapentaenoic acid; FA, Fatty Acid; IV, Independent variable; PUFA, Polyunsaturated fatty acid; RBC, Red Blood Cell.