Recovery in first episode psychosis: role of neurocognition, antipsychotics and cannabis

PhD ceremony: Mr. G. Faber, 12.45 uur, Aula Academiegebouw, Broerstraat 5, Groningen

Dissertation: Recovery in first episode psychosis: role of neurocognition, antipsychotics and cannabis

Promotor(s): prof. D. Wiersma, prof. R.J. van den Bosch

Faculty: Medical Sciences

This thesis concerns the outcome of a first episode of psychosis. In particular, the role of neurocognition, antipsychotics, and cannabis were investigated. After 2 years follow-up, 20% of patients showed clinical recovery, with functional remission as the most important prerequisite. The speed of information processing was important for the relationship between neurocognition and outcome. Poorer performance in information processing predicted worse social outcome, but a better performance did not predict better outcome. Antipsychotics are the core of the treatment of psychosis and the effects on neurocognition are therefore relevant. Based on a literature review and our own research, we conclude that antipsychotic drugs are harmful to neurocognitive functioning of psychotic patients because they slow down the speed of information processing. Thus, antipsychotic treatment should only be given when a psychosis is evident. Cannabis use increases the risk of psychosis, but it is unclear whether its continued use after the start of a first psychosis is associated with functional outcome. After two years, continued use of cannabis after a psychosis was associated with less economic and social activities. The relationship between cannabis use and the outcome was modest, but the use of cannabis should still be discouraged after the start of a first psychosis, because it is one of the few modifiable factors, and stopping or reducing the use of cannabis is an achievable goal.