medwireNews: Plasma levels of brain derived neurotrophic factor (BDNF) are associated with cognition in patients with first-episode psychosis (FEP), researchers report.
Ana González-Pinto (University of the Basque Country, Vitoria, Spain) and team found that plasma levels of BDNF at 6 months after starting treatment were positively associated with measures of cognition in a study of 45 patients with FEP.
In contrast, no association between BDNF levels and cognition was observed in 45 age-, gender-, and educational level-matched mentally healthy controls.
"Our results that patients with higher BDNF levels have better cognitive performance suggest that plasma BDNF levels could be used as a biological marker of cognition in patients with a first psychotic episode," the researchers comment.
The FEP patients were assessed for BDNF levels at hospitalization and at the 6-month follow up, when they had responded to antipsychotic treatment and recovered from the acute episode.
They also underwent a battery of 15 cognitive tests at 6 months to assess memory and learning, executive functions, working memory, processing speed, attention, and intelligence.
The researchers found that mean baseline plasma BDNF levels were significantly lower in FEP patients than controls, at 6.09 versus 9.19 ng/mL, but there was no significant between-group difference at follow up, at 8.17 and 9.19 ng/mL, respectively.
At follow up, FEP patients had significantly worse performance on most of the cognitive tests compared with controls.
In FEP patients, there was a significant positive correlation between plasma BDNF levels at 6 months and scores for abstract reasoning and processing speed, learning capacity and delayed memory, and IQ.
Multivariate regression analysis showed that plasma BDNF levels were independently associated with learning capacity, verbal delayed
memory, abstract verbal reasoning, and processing speed in FEP patients, after accounting for IQ.
In the control group, there was no significant association between plasma BDNF levels and any of the cognitive test results.
González-Pinto and team conclude in BMC Psychiatry: "Our results suggest that BDNF is associated with the cognitive impairment seen after a FEP.
"Further investigations of the role of this neurotrophin in the symptoms associated with psychosis onset are warranted."
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