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Commonly Observed Mental Disorders

Watch this video to learn about the commonly observed mental disorders in criminal trials.
I’m Dr. Danny Sullivan, I’m the executive director of clinical services at Forensicare which is the Victorian Institute of Forensic Mental Health. I’m a consultant forensic psychiatrist by training. The sorts of questions that I will ask are focused upon eliciting the particular symptoms and signs which are related to a range of psychiatric diagnoses and I want to just go over those in very limited detail.
The first category of disorders that we focus upon include cognitive impairments, that is people whose brains do not work as effectively as they should, either through intellectual disability, which they were born with, congenital intellectual disability, or through an acquired cognitive impairment, which could be through trauma, infection of the central nervous system or other health conditions, which impact upon the brain. A cognitive impairment impacting upon the brain may be elicited by cognitive testing as performed by a forensic psychologist. But there is also a general clinical impression provided by an experienced psychiatrist who is able to determine from a person’s responses, their general level of intellectual functioning and also if there are specific cognitive impairments.
Cognitive impairments can affect a range of domains of cognitive functioning, such as attention, memory, language, concentration, visuospatial or perceptual abnormalities and a range of other cognitive domains which can be elicited by specific tests. In addition, some people will have a particular history which is clear for a history of cognitive impairment, and that can include epilepsy, that can include brain trauma resulting in surgery and there may be even scars on a person’s skull that demonstrate that. And there may be a history of poor educational attainment, which was not simply a matter of opportunity, but resulted in a person leaving school prematurely.
In countries in which universal education is not the norm, it can be more difficult to determine whether a person left school because they lacked the innate capabilities to persevere and proceed, or whether, in fact their limited cognitive abilities reflect their limited educational attainment.
Determining the presence of cognitive impairment is particularly important for assessing unfitness to be tried. But it’s also relevant to mental impairment, where it impacts upon a person’s capacity to appreciate the nature and quality of their conduct or its wrongfulness.
The second group of mental disorders that we focus upon are substance use disorders, and here we need to distinguish between people who have addictions, people who abuse substances in high doses, and people who use them in a pattern which may not be healthy but is not necessarily pathological. In some situations, severe substance use disorders can cause long lasting or permanent cognitive impairments. In some cases, acute intoxication can cause acute mental health symptoms such as hallucinations, perceptual abnormalities or an inability to appreciate the truthfulness of one’s sensory experience. So it’s important to get a longitudinal pattern, remembering also that people may be willing to reduce or embellish the history that they provide of their substance use.
So once more, collateral information from family members and witnesses as well as some biochemical tests may be an important part of determining whether or not a substance use disorder is present. In many jurisdictions, a mental disorder induced by substance use is not considered to be the grounds for mental impairment. And it’s important, therefore, to reflect that people may not have this defense available even though their symptoms were present, if they were induced acutely by intoxication. The most critical interaction between the criminal justice system and offending internationally is that of psychotic disorders such as schizophrenia and related disorders.
The likelihood of people with schizophrenia offending is markedly increased in every population in which it’s ever been studied, compared to that of the general population. That is, people with schizophrenia have an increased likelihood of involvement with the criminal justice system, of violent offending, and an increased prevalence of killing. The relevance of that is that the presence of schizophrenia is of great relevance to the criminal justice system. Schizophrenia is broadly defined by three clusters of symptoms.
Positive symptoms, which are elements which are present, which are not normally present, and that includes hallucinations- hearing people talking to you or seeing things when they’re not really there, delusions- which is a fixed firm and unfounded belief which can’t be challenged by rational evidence to the contrary, and a range of other forms of interference with the perception that one controls one’s own body. We call these perceivity phenomena and they involve the sense that one’s thoughts, feelings, actions and movements may be influenced by external agencies such as spirits, gods or other people.
The second cluster of symptoms are called negative symptoms. They’re things which should be present but are lacking. So people with schizophrenia, which is a neurodegenerative disorder, a disorder causing progressive problems with thinking and a range of other cognitive functions. In the negative syndrome, people lose motivation, they lose drive, they’re not as interested in looking after themselves. They may speak less. They certainly communicate less emotion or feeling about the world. And they appear to be not functioning at the same level as other people are.
The third group of symptoms are called disorganized symptoms, and these really include disturbances of speech and thought and of behaviour, in ways that people appear to be acting in ways which don’t seem purposive or which appear chaotic or disjointed, particularly in their speech. So a clinically experienced psychiatrist should be able to determine the presence or absence of psychotic symptoms by careful observation, by asking a range of structured questions and exploring a person’s inner world or what they experience in their mind, and being able to categorize those into a range of different symptoms or signs. The next category of mental illnesses is mood disorders. And this can include depression, anxiety and a range of types of anxiety and also bipolar disorder.
And bipolar disorder includes not just depression, but also its opposite, mania or hypomania. All of these affect a person’s thinking. They affect their physical movements and activity and they affect their behaviour. And in some cases, those effects may be so severe that they can lead to offending behaviour or be associated with it. The questioning for mood disorder is also something that relies upon observation of a person’s clinical state, collateral information from other people, and a range of carefully selected questions designed to explore a person’s inner world and determine whether, compared to normal people, they would meet the criteria for a mental disorder.
There are a range of other mental disorders and all of these are set out in a series of diagnostic manuals. The two main manuals are called the Diagnostic and. Statistical Manual of Mental and Behavioural Disorders, which is currently in its fifth edition and is published by the American Psychiatric Association, and that’s called the DSM-5. Internationally, the most commonly used diagnostic classification system is the International Classification of Diseases, which is produced by the World Health Organization and is just coming into its 11th edition. It’s quite important that these forms of evidence based diagnostic criteria are used because they enable objective correlation between experts.
If I say that a person has paranoid schizophrenia, that means the same whether the person is in New Delhi, is in London, is in Melbourne, Australia or is in Antarctica. The diagnostic criteria remain the same, even though the content of their mental illness may be different. And therefore it’s important that we can use the same nomenclature and that you as lawyers and judges, can actually determine by looking at those criteria what it is that we are saying is the basis of the mental disorder. I can certainly assert that because I have a medical qualification, my diagnosis is correct.
But unless I have a foundation, a factual basis on which to make that diagnosis, and unless I can demonstrate that my diagnosis is in accord with my peers, that diagnosis remains just that- an assertion.

Forensic mental health experts focus on understanding the particular symptoms and signs which are related to a range of psychiatric diagnoses.

Are some mental disorders more prevalent than others within the criminal justice system? Are there different types of assessments for different categories of mental disorders?

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Forensic Mental Health and Criminal Justice

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