Adjunctive nutrients in first‐episode psychosis: A systematic review of efficacy, tolerability and neurobiological mechanisms

Abstract

AimThe effects of nutrient‐based treatments, including adjunctive vitamin or antioxidant supplementation, have been explored extensively in long‐term schizophrenia. However, no systematic evaluation of trials in “first‐episode psychosis” (FEP) has been conducted, despite the potential benefits of using these treatments during the early stages of illness. Therefore, we aimed to review all studies examining efficacy, tolerability and the biological mechanisms of action, of nutrient supplementation in FEP.MethodsA systematic review of electronic databases was conducted from inception to July 2017. All information on feasibility, clinical outcomes and mechanistic findings from nutrient supplementation clinical trials was extracted and systematically synthesized.ResultsEleven studies with a total of 451 patients with FEP (from 8 independent randomized controlled trials) were eligible for inclusion. Six studies examined omega‐3 fatty acids, with inconsistent effects on psychiatric symptoms. However, mechanistic studies found significant improvements in hippocampal neuronal health and brain glutathione. Antioxidants “n‐acetyl cysteine” (n = 1) and vitamin C (n = 2) also improved oxidative status in FEP, which was associated with reduced psychiatric symptoms. No benefits were found for vitamin E (n = 1). Finally, one study trialling the amino acid taurine, showed significant improvements in positive symptoms and psychosocial functioning.ConclusionThere is preliminary evidence that taurine improves outcomes in FEP, whereas effects of omega‐3 and antioxidant vitamins/amino‐acids are inconsistent; perhaps mainly benefitting patients with high levels of oxidative stress. Future studies should evaluate multifaceted dietary and supplementation interventions in FEP; targeting‐specific nutritional deficits and the range of aberrant biological processes implicated in the disorder.

The efficacy and safety of nutrient supplements in the treatment of mental disorders: a meta‐review of meta‐analyses of randomized controlled trials

“…However, the negligible effect sizes after controlling for publication bias, along with the low review quality identified by AMSTAR‐2, reduces confidence in findings. Additionally, whereas the existing meta‐analytic data have found a lack of significant benefits in people with schizophrenia, subsequent trials in young people with first‐episode psychosis have reported more positive, though mixed, results, putatively ascribed to neuroprotective effects.…”

Is Obesity in Young People With Psychosis a Foregone Conclusion? Markedly Excessive Energy Intake Is Evident Soon After Antipsychotic Initiation

“…These include specific dietitian-led interventions for weight management, which have been shown to be effective in severe mental illness (37). Further exploration is also needed for the use of adjunctive nutrients in people experiencing FEP as a potential method of improving symptoms and functioning (39).…”

Diet Quality and Mental Health Amongst Acute Inpatient Psychiatric Patients

“…There are preliminary data from RCTs suggesting that anti-inflammatory nutrients, such as omega-3 and folate-based compounds, may also be effective for other SMIs, including bipolar disorder and schizophrenia [43]. Because inflammation is particularly elevated during onset of psychotic disorders, these adjunctive treatments may have neuroprotective effects in the early stages of illness among young people [44] [45] potentially improving cognitive outcomes for some patients. However, the extent to which their effects are due specifically to their antiinflammatory properties is not fully ascertained [46].…”