Nicotine for schizophrenia

 

Abstract

Background

The proportion of people with schizophrenia who smoke is very high, and as a rule, they tend to be heavier smokers when compared to the general population and those with other psychiatric disorders. Nicotine, the psychoactive component in tobacco, is thought to produce psychological effects that help to alleviate psychotic symptoms.

Objectives

To examine the effects of nicotine and related products in the treatment of schizophrenia.

Search methods

We electronically searched the Cochrane Schizophrenia Group's Register (April 2005), supplemented with manually inspecting references of all identified studies and by contacting authors of studies where required.

Selection criteria

We included all randomised clinical trials comparing nicotine or related products as a sole or adjunctive treatment for people with schizophrenia or other similar serious, non-affective psychotic illness.

Data collection and analysis

Citations and, where possible, abstracts were independently inspected by reviewers and the papers ordered were scrutinised and quality assessed. We extracted and evaluated data independently and analysed on an intention to treat basis. We would have calculated fixed effect relative risk (RR), number needed to treat/harm (NNT/H) and their 95% confidence intervals (CI) for binary outcomes and for continuous non-skewed data we would have calculated weighted mean differences. We would have excluded data if loss to follow-up had been greater than 50% and inspected the data for heterogeneity.

Main results

We did not find any trials that met the inclusion criteria.

Authors' conclusions

There ought to be further research of nicotine for schizophrenia by parallel group design randomised controlled trials investigating the effects of nicotine on symptoms of schizophrenia as well as on side effects of antipsychotic drugs. We further note that authors and journals should conform to the CONSORT guidelines when publishing the research articles, especially when disclosing all the data available from a particular study.

 

Plain language summary

Nicotine for schizophrenia

People with schizophrenia tend to smoke heavily and to a greater extent when compared to other patient groups. In this review we aimed to investigate this by searching for good quality evidence from randomised controlled trials on the effect of nicotine for schizophrenia, and/or to ascertain whether nicotine modifies the side effects of antipsychotics. Unfortunately we found no trials that met our inclusion criteria to support or refute this. There is a need for good quality randomised controlled trials that investigate the effects of nicotine for schizophrenia.

 

摘要

背景

使用尼古丁於精神分裂症

精神分裂症患者吸煙的比率很高，且通常他們比一般大眾及其他精神疾病患者吸煙的量更大。菸草中的精神活化物質尼古丁(nicotine)，被認為是藉由產生心理影響來減輕精神症狀。

目標

檢視尼古丁及其相關產物在治療精神分裂症的作用。

搜尋策略

我們使用電腦化搜尋Cochrane Schizophrenia Group's Register(2005年4月)，輔以人工檢視所有找到的研究的相關文獻，如果需要的話會接洽研究作者。

選擇標準

我們納入所有關於精神分裂症患者或其他相似嚴重的非情感性精神疾病患者，以尼古丁或其相關產物為唯一治療或輔助治療的隨機臨床試驗。

資料收集與分析

若可能的話引用文獻及摘要都由回顧者獨立地檢視，同時對於本文進行細查及品質評估。我們獨立地擷取和評估資料且以治療意向為基礎來分析資料。針對二分法療效指標我們會去計算固定效果相對危險比(RR)、益/害一需治數(number needed to treat/harm)以及95%的CI信賴區間，而對於連續性非偏差的資料，我們會去計算加權平均差。對於大於50%失去追蹤的資料會予以排除。另外，也會去檢視資料的異質性。

主要結論

我們沒有找到任何符合納入條件的試驗。

作者結論

需要更進一步採用平行組設計的隨機對照試驗來研究nicotine對於精神分裂症症狀的效果，以及抗精神病藥物引起的副作用之影響. 我們進一步指出,作者及雜誌本身在刊登出文章時需要遵照CONSORT(Consolidated Standards of Reportng Trails)其在呈現出特定研究的所有資料時更是如此。

翻譯人

本摘要由彰化基督教醫院許文郁翻譯。

此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。

總結

精神分裂症患者往往比其他病人族群來得愛吸煙。在這篇回顧中，我們主要是目的是由隨機對照試驗中來搜尋良好品質瞭解nicotine的作用以及/或 確認是否nicotine可以減輕抗精神病藥物所導致的副作用。可惜的是我們並沒有發現符合納入條件的試驗來支持或反駁這些假設。未來需要有更好品質的隨機對照試驗來研究nicotine對於精神分裂症患者的影響。