OBJECTIVES: There is now considerable evidence that affiliative processes are linked to oxytocin (OXT), which is linked to a range of social-cognition competences underpinning interpersonal functioning. There is evidence that OXT circuitry is involved in psychosis and emerging evidence for OXT in treatment. Therefore, this study explored studies investigating OXT and improvements in symptoms and social cognition among individuals diagnosed with psychosis. METHOD: We conducted a systematic review of randomized controlled trials investigating OXT and psychosis. Specifically we asked, (1) what is the evidence that OXT is associated with improved overall, positive, negative and general symptoms and (2) what is the evidence that OXT is associated with improved social cognition? RESULTS: There were seven randomized controlled trials that met the inclusion criteria for this review. We conducted an exploratory meta-analysis of data from four of these studies on a total sample size of n = 105. For overall symptoms, using a random-effects model OXT versus placebo was associated with an effect size of d = 0.52 (95% CI = 0.34-0.70; z = 5.66; p < .01). There was evidence of significant heterogeneity (Q = 96.4, p < .001; I(2) = 96.5%). Similar patterns of findings were observed for positive, negative, and general symptoms. We found significant evidence of high risk of bias across all studies. We also identified that one particular study had an undue effect on overall effect size estimates. Finally, evidence regarding OXT was linked to improved social cognition was inconsistent. CONCLUSIONS: There are significant problems in interpreting the current evidence base for OXT in psychosis. However, OXT may provide a useful biomarker for exploring mechanisms of change occurring in psychological therapies including compassion-focused therapy (CFT), which through its engagement of the attachment system may directly influence OXT.
OBJECTIVES: There is now considerable evidence that affiliative processes are linked to oxytocin (OXT), which is linked to a range of social-cognition competences underpinning interpersonal functioning. There is evidence that OXT circuitry is involved in psychosis and emerging evidence for OXT in treatment. Therefore, this study explored studies investigating OXT and improvements in symptoms and social cognition among individuals diagnosed with psychosis. METHOD: We conducted a systematic review of randomized controlled trials investigating OXT and psychosis. Specifically we asked, (1) what is the evidence that OXT is associated with improved overall, positive, negative and general symptoms and (2) what is the evidence that OXT is associated with improved social cognition? RESULTS: There were seven randomized controlled trials that met the inclusion criteria for this review. We conducted an exploratory meta-analysis of data from four of these studies on a total sample size of n = 105. For overall symptoms, using a random-effects model OXT versus placebo was associated with an effect size of d = 0.52 (95% CI = 0.34-0.70; z = 5.66; p < .01). There was evidence of significant heterogeneity (Q = 96.4, p < .001; I(2) = 96.5%). Similar patterns of findings were observed for positive, negative, and general symptoms. We found significant evidence of high risk of bias across all studies. We also identified that one particular study had an undue effect on overall effect size estimates. Finally, evidence regarding OXT was linked to improved social cognition was inconsistent. CONCLUSIONS: There are significant problems in interpreting the current evidence base for OXT in psychosis. However, OXT may provide a useful biomarker for exploring mechanisms of change occurring in psychological therapies including compassion-focused therapy (CFT), which through its engagement of the attachment system may directly influence OXT.
Authors: Mark J Millan; Annie Andrieux; George Bartzokis; Kristin Cadenhead; Paola Dazzan; Paolo Fusar-Poli; Jürgen Gallinat; Jay Giedd; Dennis R Grayson; Markus Heinrichs; René Kahn; Marie-Odile Krebs; Marion Leboyer; David Lewis; Oscar Marin; Philippe Marin; Andreas Meyer-Lindenberg; Patrick McGorry; Philip McGuire; Michael J Owen; Paul Patterson; Akira Sawa; Michael Spedding; Peter Uhlhaas; Flora Vaccarino; Claes Wahlestedt; Daniel Weinberger Journal: Nat Rev Drug Discov Date: 2016-03-04 Impact factor: 84.694