This page explains what is meant by a psychiatric diagnosis, methods for making diag-noses, and aspects of diagnostic reliability, validity, and utility. Psychiatric and somatic comorbidities are elucidated. It includes a section on the influence of traditional medicine for most of the world’s population. It provides an overview of diagnostic interviews and screening questionnaires.
Historical development of psychiatric diagnoses:
What is a diagnosis? The word stems from dia (Greek) meaning through and gnosis (Greek) meaning knowledge, or the establishing of the nature of a disease. Making diagnoses is as old as medical history.
Diagnoses described in ancient times still hold, for example clinical depression was described by Aretaeus (81-138), who practiced medicine in Rome and Alexandria. The physician Ibn Zohr-Avenzoar (1092-1162) in Morocco described in his clinical treatment guideline acute delirium, melancholia and dementia among other psychiatric disorders, and also reported the first known account of suicide in melancholics. In 1286, Le Maristane (hospital) Sidi Frej was built in Fes, Morocco, for psychiatric patients, and was a model for the first mental asylum in the western world in Valencia, Spain, in 1410.
The term neurosis was created by the Scottish neurologist William Cullen in 1769 to label patients with nervous symptoms without an obvious organic cause. Chronic alcoholism was described by Magnus Huss in Stockholm in 1849. The German psychiatrist and neuropathologist Wilhelm Griesinger (1817-1868) laid the modern foundation of psychiatric classification in 1845, publishing a monograph on diseases of the brain. He proposed a unitary concept of psychosis. Subsequently Emil Kraepelin in Munich (1856-1926), the forefather of contemporary scientific psychiatry, split this unitary psychosis into two distinct forms based on symptom patterns that he called manic depression and dementia praecox. The Swiss psychiatrist Eugen Bleuler (1857-1939) renamed the latter schizophrenia, having determined that this disorder did not necessarily progress to dementia.
French psychiatrists made important early contributions to psychiatric diagnoses, such as Tourette’s syndrome, first described in 1885 by the neurologist Giles de la Tourette (1857-1904). He also described anorexia nervosa in 1890. Paul Hartenberg (1871-1949) eloquently described social anxiety disorder in his monograph Les Timides et la timidité in 1901.
After the second world war, the validity of psychiatric diagnoses was questioned by the United States military, since many recruits had been considered unfit for soldier duty by psychiatrists. Many combat soldiers were discharged on psychiatric grounds. There was no
Diagnosis & Classification
consensus on how to make psychiatric diagnoses. In the absence of an agreed classification, epidemiological research was not possible.
There were many thought leaders on the merits of making diagnoses. Sigmund Freud (1856-1939) postulated unconscious conflicts as the source of mental ill health, while the Swiss-born psychiatrist Adolf Meyer (1866-1950), influential in the United States, advocated that such ill health was a personality reaction to psychological, social, and biological factors. In Scotland, Ronald Laing (1927-1989) launched the "antipsychiatric" idea in 1955 that psychosis was a reaction to a cold family environment that produced a false "id," for example the case of the schizophrenogenic mother. He argued that psychiatric diagnoses rested on false grounds in that it was solely based on the patient’s conduct without external validators. The Hungarian-born American psychoanalyst Thomas Szasz (1920-) advanced the idea that psychiatric disorders are a myth, or social branding. He was embraced by the scientology movement in 1968 whose originator L. Ron Hubbard (1911-1986) in 1950 created the business of dianetics, the doctrine of the Church of Scientology, as an alternative to psychoanalysis.
The 1950s and 1960s brought critique of psychiatric diagnoses, a movement that coincided with the civil rights movement of the 1960s, and that particularly targeted the grounds for involuntary commitment to psychiatric care by means of diagnoses. When, in an experiment, several psychiatrists were asked to diagnose the same patient, it was obvious that they represented diﬀerent schools of thought that did not share a common set of definitions. This challenging of the intellectual ground of psychiatry had profound eﬀects on the allocation of resources, shifting from institutionalization to outpatient voluntary care in the United States and in Europe. In Italy all involuntary care was declared unlawful in 1978.
Two psychiatrists at Washington University in St. Louis then decided to bring sense into psychiatric diagnoses: Samuel Guze (1923-2000) and Eli Robins (1921-1995). In 1970 they published a paper on a criteria-based diagnosis of schizophrenia. This seminal paper became the intellectual basis for the 3rd version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) that was published in 1980 by the American Psychiatric Association. This fundamentally new classification was based on a consensus of clinical criteria. Also, the DSM-III did not assume etiological factors; it was based on a consensus among academic psychiatrists about the typical symptoms of a disorder and its prognosis. In 1987 and in 1994 this classification was revised, based on 150 literature surveys, and 12 field studies with more than 6000 diagnostic interviews. Work on its 5th version is ongoing, and it is to be published in 2012 (http://www.psych.org/MainMenu/Research/DSMIV/DSMV.aspx).
The DSM classification applies 5 perspectives on a patient: Axis 1 disorders (for example major depressive episode, anorexia nervosa), Axis 2 personality disorders, and neurodevelop-mental disorders), Axis 3 somatic disorders (for example diabetes mellitus, traumatic brain injury), Axis 4 current stressors (for example having been raped, bereavement), and Axis 5 global assessment of function.
One current ambition in revising the DSM classification is to pay more attention to ethnicity in understanding how symptoms may present. Gender diﬀerences will also be elucidated. The most important change in DSM-V will be the inclusion of dimensions in diagnoses; for example, how severely ill is a patient with schizophrenia or depression.
By international convention most countries use the International Classification of Dis-eases (ICD) in making all diagnoses (somatic and psychiatric) in routine health care. This classification is produced by the World Health Organization. The current ICD-
10 classification is quite similar to that of DSM-IV. The WHO is currently working its 11th revision of the ICD. With regard to the psychiatric diagnoses there is a joint eﬀort with the DSM-V developers to use similar principles and standards. The revi-sion process was formulated in 2007 and the draft version will be tested in field trials (http://www.who.int/classifications/icd/ICDRevision/en/index.html).
These eﬀorts have advanced the reliability of psychiatric diagnoses to standards similar to those of other disciplines. Methods for external validation have emerged in recent years. For example, functional magnetic resonance imaging (fMRI), and other in vivo imaging techniques, allow one to study how the amygdala reacts to an anxiety provocation in a subject with an anxiety disorder. Imaging techniques reveal disturbed CNS networks in subjects with schizophrenia, and pronounced structural aberrations in the lateral and medial parts of the temporal and frontal lobe. Untreated depression has been shown to cause cerebral shrinking. The eﬃcacy of serotonergic medications depends on neurogenesis. Latency to rapid eye movement sleep is correlated to clinical symptoms of depression. Amyloid, a protein in the plaques in Alzheimers disease, has been detected in vivo in patients in a PET study. The eﬀect of antipsychotic and antidepressant drug treatments can be correlated to symptom reduction, cerebral blood flow, and brain metabolite ratios.