The first treatment contact of persons falling ill with schizophrenia is usually preceded by incipient psychosis with a mean duration of 1 year or more and a prodromal phase of several years (Table 7.1). The length of these early phases of illness is a predictor of an unfavourable short- and long-term illness course (Crow et al., 1986; Loebel et al., 1992; McGorry et al., 1996; Wyatt et al., 1998). Hope exists that early detection and early intervention will enable us to prevent, delay or alleviate psychosis onset (McGorry et al., 1996). However, the prognostic significance of untreated psychosis or disorder is confounded by disease-related prognostic indicators: an insidious versus an acute type of onset (Verdoux et al., 2001).

The prodrome

Historical context

As early as 1861,Wilhelm Griesinger described a melancholic prodromal phase of psychotic illness. Kraepelin (1893) observed a gradual deterioration of mental functioning, disturbances of attention and daydreaming before the emergence of psychotic symptoms and ‘advanced dementia’ in dementia praecox. According to Mayer-Gross (1932), difficulties with thinking and concentration as well as loss of activity marked an insidious onset and persisted without other symptoms of the illness for long periods of time before the first psychotic symptoms appear. Eugen Bleuler (1911) called the prephase characterized by irritability, introversion, eccentricity and changes of mood ‘latent schizophrenia’. He believed that the illness could come to a halt at any stage of this early development and turn into a neurosis.