PART 2 : KEY PSYCHOLOGICAL CONCEPTS UNDERLYING PSYCHOLOGICAL ASSESSMENT AND TESTING IN FORENSIC ENVIRONMENTS

• Jurisdiction: Australia

[60.1250] Introduction

An understanding of a number of core psychological concepts is integral to the interpretation of psychological assessments (and tests) as they relate to judicial processes. Neither psychology nor psychiatry is an exact science such as physics or chemistry, where elements and processes behave the same way over repeated observations. Psychological concepts are used to help explain behaviour and they develop a certain verisimilitude through their ability to repeatedly predict how an individual might act, or what might be done to change their behaviour, (where behaviour includes processes of thought and feeling). Therefore, what psychology means and the issues associated with the terms Mental Health, Diagnosis, Motivation, Intelligence, Personality, Substance Abuse, and Psychosis is important to an understanding of specific assessment processes employed by psychologists.

[60.1260] Mental Health

Mental health is defined as a state of well-being in which every individual realizes his or her own potential, can cope with the normal stresses of life, can work productively and fruitfully and is able to make a contribution to her or his community.

- World Health Organisation, August 2014

Categorical and Dimensional

Psychological health can be thought of as being categorical or dimensional. Using a categorical medical model, psychological health is defined as "the absence of illness and ill health". States of psychological illness are categorically distinct from psychological health and this is inferred from the cognitive, behavioural and emotional patterns. Explanation and treatment is the goal in a medical model (American Psychiatric Association, 2013).

A dimensional approach, on the other hand, fails to distinguish qualitatively between health and illness, considering various psychological phenomena (intelligence, personality, motivation) as being distributed in the population in the same way as other biological traits, such as height. Most people demonstrate moderate aspects of most traits, with fewer people showing extremely little or a great deal of any given trait. Those for whom a trait is problematic and interferes with their lives are presumed to be in these extreme ranges and are captured by the categories in diagnostic manuals. The dimensional approach is more apparent in psychological literature than diagnostic manuals.

[60.1270] Diagnosis

Diagnostic classification in psychology is prototypical: a shorthand for symptoms that statistically cluster together. This allows people with very different patterns of experience or symptoms to be given the same diagnosis, and for that diagnosis to be relevant if the symptom expression changes over time. A concern with this system of classification is that psychological diagnoses are descriptions of symptoms rather than explanations of their cause, as is the case in medical diagnoses. Nonetheless, classification serves the purpose of providing a language for researchers and practitioners that allows the development of a body of literature including interventions and epidemiology.

In Australia, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5: American Psychiatric Association, 2013) is the most commonly used system for diagnosis in Australian Courts. It is noted that the International Statistical Classification of Diseases and Related Health Problems (ICD), currently in its tenth revision (with the 11^th due for release in 2018), is also used in some jurisdictions and is commonly referred to in health services. The ICD is a medical classification list by the World Health Organization (WHO) generally used for classification outsider of the United States, and particularly in Europe. However, as noted, the DSM-5 is more commonly referred to in Australia.

The DSM-5 (and its predecessors) has attracted a number of controversies and criticisms, including but not limited to diagnostic accuracy, cross cultural applicability, and pathologisation of otherwise normal expressions of human behaviour and emotion. Further, the DSM-5 does not provide guidance on treatment or intervention with any disorder. The text provides a "Cautionary Statement for Forensic Use of DSM-5" (page 25) which explicitly states that the DSM-5 "is primarily designed to assist clinicians in conducting clinical assessment, case formulation, and treatment planning" and is not designed to meet the "technical needs of courts and legal professionals". However, the authors assert that the appropriate use of the DSM-5 can assist judicial determinations where a diagnosis is relevant to the understanding of past behaviour, or to the prediction of future behaviour. However, the DSM-5 notes that a DSM-5 diagnosis does not imply that an individual meets legal...