Monday, September 14, 2009

The future of schizophrenia

Press conference at the 22nd Congress of the European College of Neuropsychopharmacology, Sept. 14, 2009, Istanbul, Turkey

Schizophrenia is a major public health problem. Affecting almost 1% of the world's population, it takes an enormous economic and social toll in addition to the distress, dysfunction, disability and mortality for those afflicted with this disease. Elements of the disease are present from birth, other aspects emerge during developmental years, and the illness becomes fully expressed in early adulthood with long-lasting implications for most patients.

Schizophrenia, which is seen as the paradigmatic psychiatric illness, presents different symptoms in multiple domains, whereby positive and negative phenomena can be separated (Falkai et al., 2005): Positive (psychotic) symptoms in a broader sense include delusions or delusional ideation, hallucinations, disturbance of association, catatonic symptoms, agitations as well as feelings of alien influence and suspiciousness. Negative symptoms include restricted range and intensity of emotional expression, limited thought and speech productivity, social withdrawal, and reduced initiation of goal-directed behaviour. These negative components are typically characterised as affective flattening, alogia, diminished drive, anhedonia and avolition. Furthermore, schizophrenia is associated with cognitive impairment, disorganised speech and behaviour, as well as poor attention. The primary advance in pharmacological treatment of schizophrenia was in 1952 with the introduction of dopamine antagonist antipsychotic drugs.

Paradigm shift in schizophrenia research: from single-disease entity to the paradigm of multiple domains

A century of work has been based on designs that conceptualise schizophrenia as a single disease entity, despite recognition that schizophrenia must have scientific status of a syndrome in the absence of proof of a single disease process (Carpenter et al., 1999). The implications are profound. Research based on the presumption that a single disease is present has produced weak findings that frequently fail confirmation in replication studies. The heterogeneity of patients receiving this diagnosis is substantial. Causal and neuropathological findings valid for some patients will not be found in others. Illness manifestations vary substantially between patients, and symptomatic components of illness are only weakly related to each other within individuals.


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