Cognitive Efficacy of Quetiapine in Early-Onset First-Episode Psychosis: A 12-Week Open Label Trial

Twenty-three adolescents with psychotic disorders, aged from 13 to 18years, participated in a 12-week open label trial (17 adolescents completed the study) in order to examine the impact of quetiapine on clinical status and cognitive functions (encompassing processing speed, attention, short-term memory, long-term memory and executive function). An improvement in Clinical Global Impression and Positive and Negative Symptom Scale (P's≤0.001) was observed. In addition, after controlling for amelioration of symptoms, a significant improvement was observed on one executive function (P=0.044; Trail Making Part B). The remaining cognitive abilities showed stability. In addition, we observed an interaction between quetiapine doses (>300mg/day or <300mg/day) and time, where lower doses showed more improvement in verbal short-term memory (P=0.048), inhibition abilities (P=0.038) and positive symptoms (P=0.020). The neuropsychological functioning of adolescents with psychotic disorders remained mainly stable after 12weeks of treatment with quetiapine. However, lower doses seemed to have a better impact on two components of cognition (inhibition abilities and verbal short-term memory) and on positive symptom