This page contains a Flash digital edition of a book.
Handbook of Forensic Psychiatric Practice in Capital Cases


Tis chapter offers guidance as to best practice concerning a range of matters that clinical psychologists are routinely asked to comment upon in relation to criminal trials.


Tis is a practical guide which deals with assessment methodologies and concentrates on psychometric assessment, describing some of the more widely used tests in each area (chosen for their robust psychometric properties), also offering an ‘at a glance’ guide in Appendix 1. Appendix 2 offers a brief description of each of the psychometric measures referred to in the text. Tese two appendices may be used as quick reference guides to appropriate practice.


Use of psychometric tests Psychometric tests and other sources of information


A central premise of clinical psychology is that all behaviour has a psychological function, and so a clinical psychology assessment offers an explanation of what may appear to be unusual, maladaptive or bizarre behaviour. Such assessment may employ formal testing of an aspect of mental functioning, for example of an individual’s intelligence quotient (IQ), by way of a standardised measure that compares the functioning of one individual with their age and culture matched peers.


Other assessments may place the behaviour in question in the context of the individual’s personality functioning, in order to describe their personality traits, plus any dysfunction they may exhibit, again as measured against a population of ‘normal’ peers, including determining whether it is sufficient to amount to ‘personality disorder’ (note psychologists define personality disorder in terms of ‘deviation from the statistical norm, whereas psychiatrists require evidence of dysfunction in aspects of normal activities of living).


All of these tests should only be used in conjunction with a thorough clinical interview and information from collateral sources (see Chapter 4 for a suggested list).


Choice of tests


In choosing which tests to administer, the following criteria must be satisfied before a test may be properly used:


• Are the tests culturally appropriate? • Have the tests been validated in the population from which the subject comes? • Do not use tests when there is uncertainty about their cultural validity


• Does the normative sample that the test was developed from match the individual to be tested? • Including demographic and clinical information


• If the two do not match then, again, it will not be possible to draw valid conclusions about the individual assessed from the test data


• Some tests, such as the WAIS-IV (a test of intelligence), have been developed extensively so as to cover ethnic diversity, age differences and offer a broad normative database


• Others, such as the MCMI-III (a questionnaire used to assess personality) have been developed for use with clinical and forensic populations only and should not be used with individuals not falling within those categories


36


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92  |  Page 93  |  Page 94  |  Page 95  |  Page 96  |  Page 97  |  Page 98  |  Page 99  |  Page 100  |  Page 101  |  Page 102  |  Page 103  |  Page 104  |  Page 105  |  Page 106  |  Page 107  |  Page 108  |  Page 109  |  Page 110  |  Page 111  |  Page 112  |  Page 113  |  Page 114  |  Page 115  |  Page 116  |  Page 117  |  Page 118  |  Page 119  |  Page 120  |  Page 121  |  Page 122  |  Page 123  |  Page 124  |  Page 125  |  Page 126  |  Page 127  |  Page 128  |  Page 129  |  Page 130  |  Page 131  |  Page 132  |  Page 133  |  Page 134  |  Page 135  |  Page 136  |  Page 137  |  Page 138  |  Page 139  |  Page 140  |  Page 141  |  Page 142  |  Page 143  |  Page 144  |  Page 145  |  Page 146  |  Page 147  |  Page 148  |  Page 149  |  Page 150  |  Page 151  |  Page 152  |  Page 153  |  Page 154  |  Page 155  |  Page 156