Neurocognitive functioning in patients with first-episode schizophrenia: results of a prospective 15-year follow-up study

To evaluate the course of neuropsychological impairment, patients with first-episode schizophrenia and healthy controls were assessed with a comprehensive test battery at the time of index treatment and after a 5- and 15-year follow-up period. Summary scores for verbal intelligence (VBI), spatial organization, verbal fluency, verbal learning, semantic memory, visual memory, delay/retention rate, short-term memory, visual–motor processing and attention (VSM) and abstraction/flexibility were constructed. Our results show that neurocognitive functioning is impaired already at the onset of schizophrenia and remains stable over the 15-year follow-up period with an improvement in VBI. With regard to the presence of a deficit syndrome, it became apparent that the group with a deficit syndrome showed a deterioration of neurocognitive functions during the follow-up period, most pronounced in VSM. On the other hand, the group without a deficit syndrome showed an improvement in neurocognitive functions at the 15-year follow-up, which exceeded the learning effects of healthy control subjects. Neurocognitive performance at index assessment strongly predicted the performance at the 15-year follow-up. Most likely due to the small sample size, there were only weak associations between treatment with different types of neuroleptics and neurocognitive performance.