Since the introduction of the concept of dementia praecox by Kraepelin, there has been debate over whether or not schizophrenia is associated with progressive cognitive decline. Methodologically, this question is mainly investigated via longitudinal studies, but it is also sometimes investigated by comparing patients with first-episode versus chronic schizophrenia. Both strategies have some advantages as well as disadvantages (see Moritz et al., 2002) and should therefore be regarded as complementary methodological tools. Inherent problems of longitudinal studies are, for example, short test-retest periods and practice effects. Cross-sectional studies, on the other hand, can easily be confounded by sample differences (especially age) and can only indirectly estimate intra-individual neurocognitive decline.

In accordance with several longitudinal studies, our investigations suggest that patients with first-episode and chronic schizophrenia display comparable neurocognitive deficits (Moritz et al., 2001; Moritz, Andresen, Schickel, Naber, & Krausz, 2002). Our results favour a neurodevelopmental model of schizophrenia over a neurodegenerative view.

Research Team

  • Prof. Dr. Martin Lambert
  • Prof. Dr. Steffen Moritz

References

Moritz, S., Lambert, M., Andresen, B., Böthern, A., Naber, D., & Krausz, M. (2001). Subjective cognitive dysfunction in first-episode and chronic schizophrenic patients. Comprehensive Psychiatry, 42, 213-216.

Moritz, S., Andresen, B., Schickel, M., Naber, D., & Krausz, M. (2002). Neurocognitive deficits in first-episode and chronic schizophrenia. European Archives of Psychiatry and Clinical Neuroscience, 252, 33-37.