A 3-year prospective study of neurological soft signs in first-episode schizophrenia

Neurological soft signs are biological traits that underlie schizophrenia and are found to occur at higher levels in at-risk individuals. The expression of neurological soft signs may be modifiable during the onset of the first psychotic episode and the subsequent evolution of the illness and its treatment. This study investigates neurological soft signs in 138 patients with first-episode schizophrenia and tracks the expression of motor soft signs in the following 3 years. For the 93 patients who have completed the 3-year follow-up, we find that neurological soft signs are stable in the 3 years that follow the first psychotic episode, and that neurological soft signs are already elevated at the presentation of first-episode psychosis in medication-naive subjects. The level of neurological soft signs at clinical stabilization is lower for patients with a shorter duration of untreated psychosis. Although the quantity of neurological soft signs does not significantly change in the 3 years that follow the first episode, the relationship between neurological soft signs and negative symptoms does not become apparent until 1 year after the initial episode. A higher level of neurological soft signs is related to a lower educational level and an older age at onset, but the level of neurological soft signs does not predict the outcome in terms of relapse or occupational functioning.