Investigating the Effects of Anxiety and Depression on Eyewitness Memory

Abstract

In recent years, vulnerability has received increased attention within a forensic context and key methods of eliciting accurate and reliable recall and identification from vulnerable witnesses have been developed (Ministry of Justice, 2011). However, the eyewitness capabilities of witnesses with a mental health problem both at interview and cross-examination are not well understood. The literature on mental health and eyewitness performance is extremely limited particularly regarding common problems, such as anxiety and depression. Also, we do not fully understand how legal professionals and jurors perceive witnesses with a mental health problem. The first study of this thesis explored legal professionals’ perceptions of witnesses with anxiety and depression and found that professionals frequently come into contact with such witnesses but the reliability of their evidence is often questioned and this is based on previous experience rather than robust evidence-based sources. Additionally, many felt that not only were changes needed to the ways such witnesses are currently interviewed, but that they should be given additional support and further mental health awareness training should be provided for professionals. The second study examined the effects of mental health on memory recall and identification accuracy. Three groups emerged: sub-clinical anxiety and depression, sub-clinical anxiety, and typical (with no mental health problems). No significant group differences in memory recall or identification accuracy were found. The third study assessed the cross-examination performance of the same three witness groups and no significant differences in cross-examination performance (measured by memory trace strength and ‘resistance’ to challenges) emerged between groups. The fourth study explored mock jurors’ perceptions of witnesses with sub-clinical anxiety and depression, and sub-clinical anxiety, compared to a typical witness with no mental health problems either with or without the provision of knowledge regarding the witness’s mental health status. The witness with sub-clinical anxiety and depression was seen to be less credible than the other witnesses and the mock jurors were more likely to consider the defendants to be not guilty after viewing the witnesses with a mental health problem. Both findings were irrespective of whether or not the mock jurors were informed of the witness’s mental health status. The findings of this thesis are discussed in relation to their real-world implications and directions for future research.

Date of Award	1 Oct 2021
Original language	English
Awarding Institution	University of Winchester
Supervisor	Rachel Wilcock (Supervisor) & Wendy Kneller (Supervisor)