Prevention of schizophrenia is difficult as there are no reliable markers for the later development of the disorder. It is unclear as of 2011 whether treating patients in the prodrome phase of schizophrenia provides benefits. There is a discrepancy between the growth in the implementation of early intervention programmes for psychosis and the underlying empirical evidence.

There is some evidence as of 2009 that early intervention in those with first-episode psychosis may improve short-term outcomes, but there is little benefit from these measures after five years. Cognitive behavioral therapy may reduce the risk of psychosis in those at high risk after a year and is recommended in this group, by the National Institute for Health and Care Excellence (NICE). Another preventive measure is to avoid drugs that have been associated with development of the disorder, including cannabis, cocaine, and amphetamines.

Antipsychotics are prescribed following a first-episode psychosis, and following remission a preventive maintenance use is continued to avoid relapse. However, it is recognized that some people do recover following a single episode and that long-term use of antipsychotics will not be needed but there is no way of identifying this group.