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Psychiatry - Diagnosis & Classification

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.

Psychiatry - Classification & Disorders

Psychiatric Comorbidity:

The criteria in the DSM-IV classification are not always specific for the disorder. Therefore, epidemiological studies produce high rates of comorbid psychiatric conditions, especially if subjects are monitored longitudinally rather than cross-sectionally (lifetime or 12-month prevalence vs. point prevalence). These are consequences of criteria-based classification that need to be accounted for in selecting subjects for research and treatment.

Subjects with a primary anxiety disorder may develop a secondary depression, causing them to seek treatment. Treating the depression uncovers the underlying primary disorder. Anxiety subjects may also self-medicate with alcohol and other substances that are anxiolytic and be diagnosed with a substance use disorder. A patient with schizophrenia may develop a depression, and unless that is properly diagnosed the antipsychotic medication may be unnecessarily increased. A patient with recurring depressive episodes may eventually develop a manic episode, thus altering the diagnosis from unipolar depression to bipolar disorder. Subjects with substance use disorders may develop psychotic reactions to e.g., cannabis or amphetamine that may mimic schizophrenia. Since subjects with schizophrenia tend to seek various drug effects, the effects of cannabis or alcohol may cause psychiatric symptoms per se. There are many more instances of comorbidity that need to be understood.

Personality disorders

An issue with the DSM-IV classification is the distinction between axis I disorders and axis II personality disorders. Personality, cognitive style, and social attitudes are moderately or highly heritable according to adoption and twin studies. There is even a genetic contribution to being religious or antisocial, and to the amount of time spent watching television! Personality traits are stable and genetically determined throughout life, and are modifiable only by serious effects such as a neurodegenerative disease, severe substance use, a traumatic brain injury, a brain tumor, or a severe generalized medical condition. One such famous case is Phineas Gage, a railroad worker who survived an iron rod that passed through his frontal lobes in 1848 and caused a pronounced personality change.

There have been many theories since Hippocrates to explain how personalities are shaped. The current explanatory model is the 5-factor model. That decribes a person along 5 different dimensions, e.g., being curious or rigid, dependable or careless, as well as degrees of self-confidence, stubbornness, shyness, and extrovertness. In the DSM-IV classification, personality disorders are assessed categorically, based on clinical assessments of cognition, affectivity, interpersonal functioning, and impulse control. If a person exhibits stable traits that deviate from the norms of the subject’s ethnic group, they may be deemed a personality disorder. There are 11 DSM-IV personality disorders divided into 3 clusters. Personality disorders occur in about 10 per cent of population samples, and in about a third of clinical samples.

The distinction between axis 1 and axis 2 disorders is sometimes unclear. A patient with a serious axis I disorder may qualify for a personality disorder diagnosis, e.g., long-standing social anxiety disorder may be regarded as a phobic personality disorder if sufficiently impaired. Yet, such a patient may respond well to treatment. A subject with high-functioning autism or Asperger syndrome may be regarded as having a schizotypal personality disorder. Attention Deficit Hyperactivity Disorder (ADHD) may be confused with antisocial personality disorder. In the work groups for the DSM-V, these issues may cause a fundamental change in dealing with axis II personality disorders.

Somatic comorbidity

Somatic disease may cause or aggravate psychiatric disorders. For example, a patient with diabetes mellitus who has taken too much insulin may present confused or agitated in the emergency room because his blood sugar is too low. A patient with hypothyroidism or hyperthyroidism or hyperparathyroidism usually has anxious or depressive symptoms. Patients with acute intermittent porphyria may become psychotic, and are always anxious. Depression is known as a risk factor for acute myocardial infarction, and can add to the risk of cardiovascular complications. Patients with stroke often develop anxiety and depression. Such manifestations of somatic disease are important to recognize, and they are diagnosed on axis III in the DSM-IV.

Premenstrual dysphoria is an intermittent cluster of symptoms among which irritability and dysphoria are the most disturbing. It develops following ovulation and reaches a peak until menstruation occurs, obviously governed by hormonal variations across the menstrual cycle.

Multiple sclerosis can present with psychotic symptoms and mood elevations including euphoria. Wilson’s disease is a disorder of copper metabolism that can cause rapid mood swings and cognitive dysfunction. Systemic lupus (SLE) can present with confusion and psychotic symptoms. Pernicious anemia (deficiency of vitamin B12) may present with depressive symptoms, memory deficits and sometimes confusion.

The medical model – is it useful?

The scientific community assumes that there is a molecular basis for psychopathology, and that symptoms are produced that can be elicited, quantified and classified by interviewing and observing a subject. This medical model was critiqued in the 1950s and 1960s, causing thought leaders to argue for external causation rather than disorders of the brain. Psychiatry was also abused for political purposes. Sane political dissidents in the Sovjet Union were sentenced by courts to be diagnosed and incarcerated in mental asylums and given tranquilizers (for some this may have been a better alternative than imprisonment).

Early support for the medical model came from twin studies that showed a strong genetic contribution to schizophrenia and bipolar disorder. Neurosyphilis, first defined in 1672, and thought to be an immoral disease, was determined to be an infectious disease in 1913. The Austrian psychiatrist Julius Wagner-Jauregg was awarded the Nobel Prize in 1927 for having shown that neurosyphilis could be treated by infecting the patient with malaria, and in 1943 patients began treatment with penicillin. The dramatic effects of lithium on mania were elucidated in the 1950s. The equally dramatic effect of chlorpromazine on delusions and hallucinations in schizophrenia was also discovered in the 1950s. With regard to anxiety, a break-through in 1964 was the finding by Donald F. Klein that imipramine could extinguish panic attacks, previously believed to stem from unconscious parental conflicts.

In recent years, the medical model has gained support from neuroimaging studies. The model has proven useful in that the benefits and hazards of psychotherapies and psychotropic medications have been shown in randomized controlled trials for which subjects with these diagnoses have been selected. The regulatory bodies of the world base their research protocols and marketing approvals on the ICD-10 and DSM-IV nosologies. Good Clinical Practice, the code by which treatment studies are undertaken, assumes that subjects are selected based on structured diagnostic interviews and that validated measures of changes in symptoms and functioning are applied (see below). The courts pronounce verdicts on forensic psychiatric assessments that are based on the medical model. The medical model is the basis for clinical research into the genetics, etiology, pathogenesis, epidemiology, treatments, and outcomes of psychiatric disorders.

The medical model is often poorly understood by lay persons in politics, administration and the media. It is attacked by the scientology movement and other antipsychiatric movements that refuse to acknowledge the scientific basis for psychiatric disorders. No wonder that the public is so confused, and that stigma against psychiatric disorders is so prevalent in many societies. Traditional medicine This paragraph is a brief excursion into the domain of traditional medicine and how it relates to psychiatric diagnoses. Examples of this interface are given.

The overwhelming majority of the world population will primarily be diagnosed and treated in traditional medicine that was developed locally by indigenous peoples:

Traditional medicine is the sum total of the knowledge, skills and practices based on the theories, beliefs and experiences indigenous to different cultures, whether explicable or not, used in the maintenance of health as well as in the prevention, diagnosis, improvement or treatment of physical and mental illness. (World Health Organization, 2000).

Complementary and Alternative Medicine (CAM) are recently developed therapies, often in opposition to evidence-based medicine:

. . . a broad domain of healing resources that encompasses all health systems, modalities, and practices and their accompanying theories and beliefs, other than those intrinsic to the politically dominant health systems of a particular society or culture in a given historical period (The Cochrane Collaboration, 2000).

There are approximately 500 000 certified practitioners of Traditional Chinese Medicine (TCM) in China, and additionally folk herbalists and "magic witch doctors," serving 56 ethnic nationalities with widely differing beliefs about illness causation, and with much stigma toward psychiatric disorders. While patients with obviously disorganized behavior will be admitted to psychiatric hospitals, those with lesser morbidities are primarily dealt with in TCM. Diagnoses are flexible from one day to another, and based on listening, observing, questioning, and pulse-taking. Religious healers, although forbidden, may apply fortune-telling, handwriting analysis, and palm-reading. They try to counteract evil spirits and repair relationships with ancestors. There is a Chinese Classification of Mental Disorders (CCMD-3) written in Chinese and in English in 2001, that includes about 40 ethnic diagnoses. One is shenjing shuairuo which emphasizes somatic complaints and fatigue, as in the ICD diagnosis neuroasthenia. Another is koro (an excessive fear of genitals and breasts shrinking back into the body).

At healing shrines in India, e.g., at the temples of Balaji in Rajasthan, most subjects have a diagnosable psychiatric illness including psychosis and severe depressive episodes. Healers name it spirit illness, and prescribe offerings and rituals at the temple and at home.

In Japan, Morita therapy was devised by a psychiatrist, and draws from Zen Buddhism, aiming to make people accept their destiny, and live with the symptoms that are similar to social anxiety disorder in the DSM-IV. There is a period of absolute rest, then a period of light work, followed by a period of normal work. In studies more than one half of all patients, including those with schizophrenia, had seen a traditional healer or shaman (yuta) before seeking psychiatric treatment. Taijin Kyofosho (anthropophobia, phobia of eye contact) is a culture-bound syndrome, rooted in consideration for others, loyalty to the group, protecting a vertical society, mutual dependence, a sense of obligation, and empathy.


In the Xhosa tribe in South Africa, amafufuynana and ukuthwasa are culture-bound syn-dromes that overlap with the DSM-IV criteria for schizophrenia. Both include delusions, hallucinations, and bizarre behaviour. A young person with ukuthwasa is a candidate to become a traditional healer, as he/she can communicate with ancestors, and resisting such a calling may cause illness. There is often a family history of schizophrenia and other psychiatric disorders among those with ukuthwasa. Amafufuynana is believed to be caused by sorcery.

In Quichuas, an Amerindian nation in South America, someone who suffers from anxiety or depression according to the DSM classification is diagnosed as the victim of sorcery or bad spirits.

In the United Kingdom, South Asian patients, including Muslims from Pakistan, frequently seek traditional healers (hakims), practicing Unani Tibbia that stems from Jundishapur south of Teheran. Psychiatric disorders are treated with herbs, diets, and amulets with holy words from the Koran, or the patient is referred to a mullah. Such treatments are often conducted in tandem with biomedical treatments. African-Caribbean patients employ counter-measures including religious rituals and magic (Obeah - witchcraft), having consulted divine healers from the Pentecostal or other churches.

In Italy, the Catholic Charismatic Renewal, sanctioned by the Pope, stems from the Pentecostal cult and includes 300 000 believers. Illness, according to the Catholic doctrine of 2000, is closely related to Evil; it can be God’s punishment for sins, and healing by God can be obtained by collective prayer that produces exalting salvation and jubilation.

These are some brief examples of the multitude of traditional explanations and treatments that are used for the large majority of the world’s population. Traditional healers are a major force in global mental health, as about 40 per cent of their clients suffer from mental illnesses. A psychiatrist trained in evidence-based medicine thus needs to develop an understanding of the large influence of such faiths on patients with psychiatric disorders, even in technologically advanced societies, and need to adjust for it to establish a therapeutic alliance and improve the chances of a favorable outcome.

Next-> Structured diagnostic interviews and screening questionnaires