Brain-Derived Neurotrophic Factor (BDNF) and First-Episode Psychosis. A longitudinal one-year prognosis study
Keywords:
BDNF, first episode psychosis, schizophrenia, prognosisAbstract
Introduction. The brain-derived neurotrophic factor (BDNF) is a neurotrophin that has been linked to the schizophrenia neurodevelopmental hypothesis. Several studies confirm that the BDNF levels in first-episode psychosis (FEP) are lower than in healthy controls (HC). However, data about evolution of BDNF levels after a FEP and about the prognostic value of these levels are controversial.
Method. Serum BDNF levels at admission of 28 inpatients with FEP were compared with 28 HC. BDNF was also measured at discharge, three, six, nine and twelve months. BDNF levels are presented in ng/ml. We looked for correlation of BDNF levels with the psychotic symptomatology measured with the Positive and Negative Syndrome Scale (PANSS) and also the prognostic value of basal levels was evaluated to predict poor functionality (measured by the Global Assessment of Functioning) and/or relapse, as well as the subsequent diagnosis of a chronic psychotic disorder.
Results. At admission, patients BDNF levels were significantly lower than HC levels (18.52±4.51 vs. 26.55±3.22, p<0.001). At discharge FEP levels increase until HC levels (25.95±3.96 vs. 26.55±3.22, p=0,539). Upon the following determinations, BDNF FEP levels decreased, reaching the admission values, and being significantly lower than the HC and the levels at discharge (patients: three months: 19.68±3.88; six months: 19.02±4.13; nine months: 17.64±5.24; twelve months: 17.51±3.45 vs. HC: 26.55±3.22, all p<0.001).
A negative correlation was found between admission BDNF levels and the PANSS negative symptoms subscale score with a trend towards significance (r=-0.303, p=0.093). BDNF levels at admission of patients with por functionality and/or relapse at 12 months were lower than BDNF levels of patients with goof functionality and without relapse, this difference had a trend towards significance. (15.38±4,72 vs. 19.57±4.06; p=0.071). We didn´t found differences between basal BDNF levels of patients who developed a chronic psychotic disorder and patients who didn’t.
Conclusions. Our results reinforce the neurotrophin hypothesis. Basal levels (at diagnosis) of a FEP could predict the prognosis in terms of functionality and risk of relapse in the first year.
