Antipsychotic drug treatment for elderly people with late-onset schizophrenia

Abstract

Background: At least 0.1% of the world's elderly population have a diagnosis of schizophrenia that started late in life and prognosis may be made worse by delay and avoidance of treatment.

Objectives: To assess the effects of antipsychotic drugs for elderly people with late-onset schizophrenia.

Search strategy: We searched the Cochrane Schizophrenia Group trials register (September 2002). This register is compiled by methodical searches of BIOSIS, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, Dissertation Abstracts, EMBASE, LILACS, MEDLINE, PSYNDEX, PsycINFO, RUSSMED, Sociofile, supplemented with hand searching of relevant journals and numerous conference proceedings. References of all identified studies were also inspected for more trials.

Selection criteria: All relevant randomised controlled trials that compared atypical antipsychotic drugs with other treatments for elderly people (at least 80% of whom should be over 65 years of age) with a recent (within five years) diagnosis of schizophrenia or schizophrenia like illnesses such as delusional disorder, schizoaffective disorder, schizophreniform psychosis or paraphrenia.

Data collection and analysis: All citations were inspected by the principal reviewer (SA) and papers ordered and re-inspected (by IA, NAQ, SP) to ensure reliable selection. Methodological quality of trials would have been assessed using the Cochrane Reviewers' Handbook criteria and data would have been independently extracted. Data were to have been excluded if loss to follow up was greater than 50%. For homogeneous dichotomous data the relative risk (RR), 95% confidence interval (CI), and the number needed to treat (NNT) and number needed to harm (NNH), were to have been calculated based on an intention-to-treat basis.

Main results: Electronic searching produced 119 references, 65 of which were selected for examination of the full text. These referred to 38 studies. Not one study met the entry criteria for this review. Most were randomised but involved elderly people with chronic schizophrenia. Four trials involved people with schizophrenia, and did include a minority who suffered from paraphrenia. Outcomes for this sub-group, however, were not reported. One randomised study (n=18) did focus on late onset schizophrenia, but unfortunately the two treatments under evaluation, remoxipride and thioridazine, have both been withdrawn from use.

Reviewer's conclusions: There is no trial-based evidence upon which to base guidelines for the treatment of late onset schizophrenia. This review highlights the need for good quality controlled clinical trials to address the effects of antipsychotic drugs for this group. Such trials are possible. Until they are undertaken people with late onset schizophrenia will be treated by doctors using clinical judgement and habit to guide prescribing.