Although antipsychotics are widely prescribed, their effect of on improving poor illness insight in schizophrenia has seldom been investigated and therefore remains uncertain. This paper examines the effects of low dose haloperidol, amisulpride, olanzapine, quetiapine, and ziprasidone on insight in first-episode schizophrenia, schizoaffective disorder, or schizophreniform disorder.

The effects of five antipsychotic drugs in first episode psychosis on insight were compared in a large scale open randomized controlled trial conducted in fourteen European countries: the European First-Episode Schizophrenia Trial (EUFEST). Patients with at least minimal impairments in insight were included in the present study (n=455). Insight was assessed with item G12 of the Positive and Negative Syndrome Scale (PANSS), administered at baseline and at 1, 3, 6, 9, and 12 months after randomization.

The use of antipsychotics was associated with clear improvements in insight, independent of other symptoms. This effect was most pronounced in the first three months of treatment, with quetiapine being significantly less effective than other drugs.

Use of antipsychotics was associated with an improvement in insight, over and above their effects on other symptoms of schizophrenia. Effects of spontaneous improvement cannot be ruled out due to the lack of a placebo control group, although such a large spontaneous improvement seems unlikely. Notably, the improvement of insight was less pronounced for quetiapine compared to haloperidol, amisulpride, olanzapine, quetiapine, and ziprasidone.