Original articleA meta-analysis and critical review of the effects of conventional neuroleptic treatment on cognition in schizophrenia: opening a closed book
Section snippets
Identification of studies
To examine the effects of conventional neuroleptic medication on the cognition of patients with schizophrenia, we endeavored to locate all studies that examined the impact of antipsychotic medication on some aspect of cognition with a generally acceptable cognitive, neuropsychological, or information-processing measure by comparing the performance of patients taking and not taking medication (i.e., with a placebo arm). The corpus of primary studies was limited to those studies that compared
Results
Initially, 224 effect sizes were obtained from data extracted from 36 articles, including 26 effect sizes from studies that were estimated from t, F, or p values. Some primary studies (Gilbertson and van Kammen, 1997, Killian et al., 1984, Oltmanns et al., 1978) conducted between-subjects and within-subject comparisons with the same subjects. To not give undue weight to such studies, we computed effect sizes in these cases from the between-group comparisons because the majority of studies in
Discussion
Contrary to conventional wisdom and some narrative reviews, including our own (Goldberg and Gold, 1995, Goldberg and Weinberger, 1996), typical antipsychotic medication provides modest to moderate gains in most cognitive domains tested in patients with schizophrenia. This enhancing effect did not rest on outlier studies, study qualities involving subject allocation, the blind, patient characteristics, or discernible aspects of subjects' clinical status. The results were not artifacts of
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2020, NeuropharmacologyCitation Excerpt :Up to 80% of patients with schizophrenia have some form of cognitive impairment (Reichenberg et al., 2009), which may predate the onset of schizophrenia (Bora and Murray, 2014) and is associated with poor outcomes (Green, 2016). Antipsychotics improve cognitive functioning in first episode and chronic patients when cognitive testing is repeated over time, but there seems to be little difference between agents and some patients show limited improvement (Davidson et al., 2009; Keefe et al., 2007; Mishara and Goldberg, 2004; Nielsen et al., 2015; Woodward et al., 2005). Molecular imaging studies have linked dopaminergic function to performance on cognitive tasks.