Correspondence

Commission of policy advice from the Animals in Science Committee: the use of the forced swim test under ASPA

Published 7 October 2022

22 August 2022

Summary

A review of the use of the forced swim test under the Animals (Scientific Procedures) Act 1986 (ASPA) is merited following the recent publication of studies on the forced swim test and alternatives, and concerns raised over the reliability of the test in certain circumstances and the justification of harms.

The UK Government wishes to receive advice from the Committee on the evidence of alternative methods and appropriate justification for the use of the forced swim test, under ASPA, with due consideration to the legitimate requirements of science and industry and to the protection of animals.

1.Policy issue

The use of the forced swim test has been the subject of recent scientific studies and advocacy. Recent published papers have highlighted areas where the forced swim test can be an effective tool and also where it has shortcomings.

There is evidence of public concern regarding the use of the test in scientific research projects. A worldwide advocacy campaign, calling for the use of the test to be banned led to significant public engagement with the issue.

Advice on the availability of alternative methods and appropriate justification for the use of the forced swim test can be used to inform good practice in the science sector and better regulation by the government.

2.Context

What is the forced swim test?

The forced swim test, also known as the porsolt test, is a behavioural test used to test the efficacy of potential antidepressant treatments. The test involves placing a rodent in a container of water from which they cannot escape. Time spent mobile and immobile under the effect of a test substance is measured to inform an assessment of efficacy.

The test is stressful to the animal and is typically classified as a moderate severity scientific procedure. Forced swim tests with exhaustion as the end point are classified as severe (ASPA Guidance Appendix G). ^{[footnote 1]}

How is it currently regulated?

The Home Office will only grant a project licence for a programme of work for a permissible purpose under ASPA and where the scientific objective cannot be achieved without using animals.

Before project licences can be authorised under ASPA the programme of work is assessed to determine whether the harm that would be caused to protected animals in terms of suffering, pain and distress is justified by the expected outcome, taking into account ethical considerations and the expected benefit to human beings, animals or the environment.

ASPA requires that animals are only ever used in science where there are no alternatives, where the number of animals used is the minimum needed to achieve the scientific benefit, and where the potential harm to animals is limited to that needed to achieve the scientific benefit.

Establishments conducting research are required to have internal governance systems and processes that ensure that the regulated activities carried out at the establishment are undertaken in accordance with the principles of the 3Rs (replacement, reduction and refinement). All licences issued under ASPA are subject to Standard Conditions ^{[footnote 2]} which require the application of the 3Rs to the use of animals in scientific procedures.

3.Evidence

Papers published on the use of the forced swim test have included the following findings. This is not intended to be a comprehensive picture of the available evidence.

a) There is not a UK regulatory requirement to carry out the test. ^{[footnote 3]}

b) The test is not essential for demonstration of efficacy for regulatory purposes. ^{[footnote 3]}

c) The test is effective for the purpose of screening antidepressants. ^{[footnote 3] [footnote 4]}

d) The forced swim test has a low accuracy rate for identifying novel antidepressants. ^{[footnote 5]}

e) The test is not considered a model for depression in humans. ^{[footnote 3] [footnote 4]}

f) For antidepressant screening there are no non-animal alternatives or less harmful animal tests currently available. ^{[footnote 3] [footnote 4]}

g) There are potential alternatives that could reduce animal harm, such as neurochemical methods or the use of Drosphila flies. ^{[footnote 3] [footnote 6]}

4.Advice sought from the Animals in Science Committee

It is requested that upon review of the evidence base that the Committee specifically provides a response to the question:

How should the 3Rs be applied regarding the forced swim test, drawing on the available evidence and licence review?

The Committee may wish to make other recommendations as it sees appropriate.

The Committee is asked to provide written advice on the question set out above by 31 January 2023.

5.Process

How will the Committee provide advice?

The Committee will provide written advice to the UK Government in line with its statutory remit, as set out in ASPA ^{[footnote 7]} Section 20:

1. The Committee must provide advice to the Secretary of State and the Animal Welfare and Ethical Review Bodies on such matters relating to the acquisition, breeding, accommodation, care and use of protected animals as the Committee may determine or as may be referred to the Committee by the Secretary of State.

2. In its consideration of any matter the Committee shall have regard both to the legitimate requirements of science and industry and to the protection of animals against avoidable suffering and unnecessary use in scientific procedures.

3. The Committee must take such steps as it considers appropriate to ensure the sharing of best practice in relation to the acquisition, breeding, accommodation, care and use of protected animals.

In developing advice, the Committee will wish to gather relevant evidence by engaging with relevant stakeholders concerned with science and industry, animal protection, and regulated establishments.

How will the Committee’s advice be used?

The UK Government will carefully consider the Committee’s advice, alongside wider policy legal and political considerations, before reaching a policy decision. If necessary the government may revert to the Committee for further advice or clarification.

The government will continue to engage with the Committee to support the implementation of any policy decision and to monitor the impacts.

Footnotes

1. Guidance on the operation of the Animals (Scientific Procedures) Act 1986 ↩

2. Personal licence: standard conditions; Project licence: standard conditions; Establishment licence: standard conditions ↩

3. Preclinical screening for antidepressant activity – shifting focus away from the Forced Swim Test to the use of translational biomarkers ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

4. Factsheet on the forced swim test, Understanding Animal Research ↩ ↩² ↩³

5. The forced swim test has poor accuracy for identifying novel antidepressants ↩

6. Validation of the forced swim test in Drosophila, and its use to demonstrate psilocybin has long-lasting antidepressant-like effects in flies, National Library of Medicine ↩

7. Animals (Scientific Procedures) Act 1986 ↩