Psychiatry

Forensic psychiatric evaluations are crucial to many civil and criminal court decisions. Psychiatrists are requested to assess the level of criminal and legal responsibility of defenders in cases of fraud, embezzlement, murder, physical aggression, disputes for child custody, and other crimes and court proceedings. In some countries, when a person decides to write a will, his or her mental sanity has to be established in order to prevent disputes among heirs about the legal validity of the will based on allegations of the author's mental health at the time the document was written. Other roles of forensic psychiatry involve studying the psychiatric risk factors for criminal behavior among the population, to evaluate inmates for probationary release, and to research the neurobiological aspects of psychopathic personalities and the risk they may pose to society.

Psychiatry is the field of medical sciences that studies mental diseases and behavioral disorders associated with biological causes. Congenital (present at birth), hereditary, or acquired psychosis, mania, and schizophrenia can often lead to violent or self-destructive behavior and deviant patterns of social interactions. In contrast to psychiatry, psychology investigates behavioral, emotional, and cognitive disorders. Psychology also studies the unconscious mechanisms underlying life experiences and mental illness. Both psychiatry and psychology study the development of personality from birth to adulthood, and the psychological (emotional and cognitive) and social or interpersonal developmental needs of each phase of life. However, the medical diagnosis and treatment of psychosis and other psychiatric disorders is the exclusive domain of the psychiatrist, whereas the counseling and cognitive re-education of patients suffering from nonpsychotic disorders, such as neurosis, behavioral problems, and emotional traumas, is usually the role of the psychologist.

Neuropsychiatry or the clinical application of the findings of neuroscience to the diagnosis and treatment of psychiatric disorders has yielded a better understanding of the biological bases of violent and criminal behavior associated with some psychopathologies, as well as a number of new effective diagnostic techniques. Since the 1970s, many neuroscience studies have shown that the brain structures and neurochemistry can be modified during infancy and childhood by the repetitive exposure to traumatic experiences or to neglect. Whereas less than 1% of any given population may present hereditary psychosis, these studies have shown that children born with a healthy brain can be neurologically damaged by chronic exposure to maternal neglect, child abuse, or a violent environment, even if the child is not the direct target of the violence. The brain adapts to such situations by undergoing detrimental and often permanent changes in its structures and neurochemical functions that often lead to psychosis and violent behavior, or to self-destructive patterns and other psychiatric pathologies. Such knowledge is leading many psychiatrists to work in the early detection of children at risk in order to prevent further damage through early diagnosis and treatment of abused children. Forensic psychiatry is therefore, crucial to the evaluation of children victimized by domestic or social violence and/or neglect, and for informing courts and social agencies on the therapeutic needs and available treatments in this vulnerable age group.

Forensic psychiatry differs in nature from clinical psychiatric practice because it aims to prove a fact in court, and is subjected to scrutiny and cross-examination by opposing parts. It requires a wide range of specific studies and adequate techniques as well as a special training in order to enable the psychiatrist to act as an expert examiner and witness in court. The psychiatric examiner supplies prosecutors, judges, probation boards, and police investigators with expert diagnosis on the mental state of defenders, convicts, and suspects. Such forensic diagnosis will constitute evidence to be considered by judges and/or by the court.

Expert psychiatric evaluation may be divided in three categories: transversal (or horizontal) evaluation, retrospective evaluation, and prospective evaluation. Transversal evaluations aim to establish whether the defendant is suffering in the present from a psychiatric disorder that would acquit him of civil or criminal responsibility. However, an insanity diagnosis implies in many cases the compulsory reclusion to a psychiatric hospital and treatment. If the psychiatric offender poses serious threat to himself and to other people's lives, he can be committed to a mental institution for life. Transversal evaluations are usually requested by the defense or by the prosecution before the trial or in the initial phases of the trial, and are obligatory by law in many countries. Retrospective evaluations require great expertise and technical preparation from forensic psychiatrists in order to infer the mental condition and legal responsibility of the defender at the time he committed the crime. Prospective evaluations, or risk assessment, consist of evaluations based on the present and past history of a convict, or a defendant to determine future risk of recidivism (repeated criminal behavior). It is usually carried out by a multidisciplinary team when prisoners are being assessed for probation, or by the forensic psychiatrist alone to enable the judge to determine the length of a new sentence in cases of repeated offenses.

Another field of forensic psychiatry involves researching the incidence of crime in the population, and is known as crime epidemiology. One such study sponsored by the National Institute of Mental Health (NIMH) was completed in 2002. An entire generation of boys in the city of Dunedin, New Zealand, was periodically evaluated from birth through physical, psychiatric, neurological, and psychomotor tests. In 2002, the group donated blood for genetic tests, including those who had a record as juvenile offenders in recent years or were serving sentences for violent crimes. It was found that in addition to having been victims of serious abuse or neglect during childhood, a subpopulation among the delinquent group had a genetic mutation that affected the regulation of a chemical messenger in the brain. Although this subgroup represented only 12% of the delinquents, they accounted for 44% of convictions for violent crimes.

The adoption of psychiatric diagnostic guidelines by some countries in the past 20 years, which are regularly updated to include new scientific advances, are essential for modern forensic psychiatry. The process of forensic psychiatric evaluation can be generally described as requiring interviews with the examinee, clinical physical examination, neurological and endocrine tests, neurological and functional diagnostic tests, neuropsychological assessments, and interviews with third parties. Based on the results of these various tests, forensic psychiatrists issue expert reports and prepare evidence for presentation in court. In the United States, a forensic psychiatric diagnosis is based on the Diagnostic and Statistical Manual of Mental Disorders, developed by the American Psychiatric Association. In many other countries the World Health Organization (WHO) guidelines are used, such as the Clinical Descriptions and Diagnostic Guidelines and the Diagnostic Criteria for Research.

Advancements in neuroscience and the establishment of objective criteria for psychiatric diagnostics as well as the clear and detailed description of the etiology (causes) and ethology (progression) of psychopathologies (serious mental disorders) were important to forensic psychiatry, as these advancements rid the profession of the controversial character often attributed to forensic psychiatry in the past. The APA system adopts objective formulations, similar to those used in other medical specialties. Diagnostic techniques introduced or improved in the last two decades, such as functional brain magnetic resonance imaging (fMRI), PET scans, and computer tomography, allow the identification of structural asymmetries and functional abnormalities of the brain associated with some mental illnesses. The same is true for new laboratorial neuroendocrine tests, which give insight into brain chemistry. The advances of neurosciences and the better understanding of brain chemistry gave forensic psychiatry a new scientific status as an objective science, using clear diagnostic parameters and criteria. Therefore, allegations of insanity by defenders can now be proved or disproved on the basis of solid scientific evidence.