RESUMEN
Background: Sub-optimal response in schizophrenia is frequent, warranting augmentation strategies over treatment-as-usual (TAU). Methods: We assessed nutraceuticals/phytoceutical augmentation strategies via network meta-analysis. Randomized controlled trials in schizophrenia/schizoaffective disorder were identified via the following databases: PubMed, MEDLINE, EMBASE, Scopus, PsycINFO, CENTRAL, and ClinicalTrials.gov. Change (Standardized Mean Difference=SMD) in total symptomatology and acceptability (Risk Ratio=RR) were co-primary outcomes. Secondary outcomes were positive, negative, cognitive, and depressive symptom changes, general psychopathology, tolerability, and response rates. We conducted subset analyses by disease phase and sensitivity analyses by risk of bias and assessed global/local inconsistency, publication bias, risk of bias, and confidence in the evidence. Results: The systematic review included 49 records documenting 50 studies (n=2,384) documenting 22 interventions. Citicoline (SMD=-1.05,95%CI=-1.85; -.24), L-lysine (SMD=-1.04,95%CI=-1.84;-.25), N-acetylcysteine (SMD=-.87,95%CI=-1.27;-.47) and sarcosine (SMD=-.5,95%CI=-.87-.13) outperformed placebo for total symptomatology. High heterogeneity (tau2=.10, I2=55.9%) and global inconsistency (Q=40.79, df=18, p=.002) emerged without publication bias (Egger's test, p=.42). Sarcosine improved negative symptoms (SMD=-.65, 95%CI=-1.10; -.19). N-acetylcysteine improved negative symptoms (SMD=-.90, 95%CI=-1.42; -.39)/general psychopathology (SMD=-.76, 95%CI=-1.39; -.13). No compound improved total symptomatology within acute phase studies (k=7, n=422). Sarcosine (SMD=-1.26,95%CI=-1.91; -.60), citicoline (SMD=-1.05,95%CI=-1.65;-.44), and N-acetylcysteine (SMD=-.55,95%CI=-.92,-.19) outperformed placebo augmentation in clinically stable participants. Sensitivity analyses removing high-risk-of-bias studies confirmed overall findings in all phases and clinically stable samples. In contrast, the acute phase analysis restricted to low risk-of-bias studies showed a superior effect vs. placebo for N-acetylcysteine (SMD=-1.10,95%CI=-1.75,-.45), L-lysine (SMD=-1.05,95%CI=-1.55,-.19), omega-3 fatty acids (SMD=-.83,95%CI=-1.31,-.34) and withania somnifera (SMD=-.71,95%CI=-1.21,-.22). Citicoline (SMD=-1.05,95%CI=-1.86,-.23), L-lysine (SMD=-1.04,95%CI=-1.84,-.24), N-acetylcysteine (SMD=-.89,95%CI=-1.35,-.43) and sarcosine (SMD=-.61,95%CI=-1.02,-.21) outperformed placebo augmentation of TAU ("any phase"). Drop-out due to any cause or adverse events did not differ between nutraceutical/phytoceutical vs. placebo+TAU. Conclusions: Sarcosine, citicoline, and N-acetylcysteine are promising augmentation interventions in stable patients with schizophrenia, yet the quality of evidence is low to very low. Further high-quality trials in acute phases/specific outcomes/difficult-to-treat schizophrenia are warranted.
RESUMEN
Azapirones have been proposed as anxiety and mood modulators. We assessed azapirones' viability in anxiety disorders via systematic review and random-effects meta-analysis, inquiring PubMed/MEDLINE/CENTRAL/WHO-ICTRP/WebOfScience/VIP up-to 05/01/2023. We conducted sensitivity, and subgroup analyses assessing heterogeneity, publication bias, risk of bias, and confidence in the evidence within the GRADE framework. Symptom reduction (mean difference/MD), study-defined response (risk ratios/RRs), and acceptability were co-primary outcomes. Adverse events and withdrawal were secondary. Seventy studies were included. In generalized anxiety disorder (GAD), azapirones largely outperformed placebo (MD=-4.91, 95%C.I.[-5.91, -3.90], Hedges'g -1.37 [-1.02, -0.73]), k = 22, n = 2,567; RR=1.64, 95%C.I.[1.45, 1.86], k = 9, n = 1,346). While azapirones overlapped benzodiazepines in symptom reduction (MD=-0.12, 95%C.I.[-0.70, 0.45], k = 34, n = 3,160), they were slightly outperformed in response rate (RR=0.94, 95%C.I.[0.90, 0.99], k = 18, n = 2,423). Azapirones overlapped SRIs (MD=0.09, 95%C.I.[-0.49, 0.67], k = 8, n = 747; RR=0.97, 95%C.I.[0.89, 1.07], k = 7, n = 737). Confidence in estimates was high/moderate vs. placebo, moderate/low vs. benzodiazepine, very-low vs. SRIs. Azapirones failed to outperform the placebo in panic and social anxiety disorders. Azapirones overlapped placebo and SRIs in drop-out rates, while they showed higher treatment discontinuation rates than benzodiazepines (RR=1.33, 95%C.I.[1.16, 1.53], k = 23, n = 2,768). Azapirones caused less sedation/fatigue/drowsiness/weakness/cognitive issues than benzodiazepines, resembling placebo. They caused more nausea and dizziness than placebo, more headache and nausea than benzodiazepines, and less nausea and xerostomia than SRIs. Azapirones proved effective and relatively well-tolerated for GAD. They should be preferred over benzodiazepines, especially in the long-term, considering their lower sedation and addiction potential, representing a potential SRI alternative. Further research is warranted to prove efficacy in panic and social anxiety.
