Unsolved problems in medicine

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This article discusses notable unsolved problems in medicine . Many of the problems relate to how drugs work (the so-called mechanism of action), and to diseases with an unknown cause, the so-called idiopathic diseases.

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Definition of "disease"

There is no overarching, clear definition of what a disease is. On one hand, there is a scientific definition which is tied to a physiological process, and on the other hand, there is the subjective suffering of a patient and the loss of their life quality. Both approaches do not need to match, and they can even be contradictory.

For example, when a patient seeks medical help because of a severe flu, the doctor will not care about the specific virological and immunological process behind the clearly visible suffering. This is contrasted by many hemochromatosis patients who will neither see suffering nor a change in his life quality, while the disease-causing process is severe and often deadly if left untreated. Similarly, many cancers in their very early stages are asymptomatic (e.g. pancreatic cancer) and the patient still feels healthy, which delays seeking treatment.

Sometimes, cultural factors also play a role in defining "disease". Erectile dysfunction was long seen as a negative but non-pathological state. The introduction of effective treatments has led to its acceptance as a disease. [1]

Even more difficulties arise when it comes to mental disorders. Depressions and anxiety disorders cause significant subjective suffering in the patient, but do not harm third persons. On the contrary, a narcissistic disorder or an impulse-control disorder does not cause any suffering in the patient, though the maintenance of healthy interpersonal relationships will be affected, and third persons can be harmed. There is also debate on whether non-normal behavior like paraphilias should be classified as a disease if they neither cause subjective suffering in the patient, nor endanger third persons.

Evidence-based medicine

Evidence-based medicine (EBM) has become the central paradigm in medical practice and research. However, debate continues around EBM and about how results obtained from large samples of patients can be applied to the individual. [2] [3] [4] [5]

Psychiatry and psychology

Lack of reliable diagnoses in some disorders

Though manuals like the DSM have covered a lot of ground when it comes to defining mental illnesses, in some disorders the reliability of diagnosis is still very poor. For example, inter-rater reliability in cases of dementia is very high, with a kappa value of 0.78, while major depressive disorder is often diagnosed differently by independent experts who see the same patient, with a kappa value of just 0.28. [6]

Cultural issues in defining mental disorders

Some mental illnesses like paraphilias are still defined by societal and cultural norms, rather than putting the individual's well-being in focus. For example, DSM defined homosexuality as a mental illness, until the American Psychiatric Association decided otherwise in 1973. As Richard Green pointed out in a review on pedophilia, psychiatry should identify unhealthy mental processes and treat them, and not focus on cultural norms, moral questions or legal issues. [7]

As textbooks and handbooks like DSM are usually written by Western authors, a culturally neutral definition of mental diseases is an unsolved problem. Though newer editions of the DSM “respect” non-Western cultures by mentioning culture-specific symptom presentations (e.g. a very long time of mourning is regarded as a sign of depression in some cultures, but not in others), the inclusion of cultural factors into diagnostic criteria is seen as a political decision, but not a scientifically founded one. The Western viewpoint when defining mental illnesses also creates a cultural blind spot: Manuals rarely discuss how Western lifestyles and cultures may modify or hide symptoms of mental illnesses. [8]

Still no causal classification of mental disorders

A patient with a paralysis is referred to an oncologist if the condition is caused by a cancer metastasis in the spinal cord; a treatment by a neurologist is a secondary consideration. Likewise, renal insufficiency is sometimes caused by heart problems, and the treatment is thus led by a cardiologist. In psychiatry, however, grouping mental disorders by their cause is still an unsolved problem. Psychiatric textbooks and manuals cluster disorders by symptoms, which is thought to impede the search for effective treatments. This has been compared to an ornithologist's field guide: It allows you to identify birds, but it does not tell you why a species exists in biotope A but not B. [9]

Diseases with unknown cause

There are numerous diseases for which causes are not known. There are others for which the etiology is fully or partially understood, but for which effective treatments are not yet available.

Idiopathic is a descriptive term used in medicine to denote diseases with an unknown cause or mechanism of apparent spontaneous origin. [10] Examples of idiopathic diseases include: Idiopathic pulmonary fibrosis, Idiopathic intracranial hypertension, and Idiopathic pulmonary haemosiderosis. Another example is that the cause of aggressive periodontitis – resulting in rapid bone loss and teeth in need of extraction – is still unknown. [11]

Mechanisms of action

It is sometimes unknown how drugs work. Often it is possible to study gene expression in a model organism, and determine the genes that are inhibited by a certain substance, and make further inferences from this data. A classical example of an unknown mechanism of action is the mechanism of general anesthesia. Other examples are paracetamol, antidepressants and lithium.

See also

Related Research Articles

<span class="mw-page-title-main">Disease</span> Condition negatively affecting an organism

A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are associated with specific signs and symptoms. A disease may be caused by external factors such as pathogens or by internal dysfunctions. For example, internal dysfunctions of the immune system can produce a variety of different diseases, including various forms of immunodeficiency, hypersensitivity, allergies, and autoimmune disorders.

<i>Diagnostic and Statistical Manual of Mental Disorders</i> American psychiatric classification

The Diagnostic and Statistical Manual of Mental Disorders is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common language and standard criteria. It is the main book for the diagnosis and treatment of mental disorders in the United States and Australia, while in other countries it may be used in conjunction with other documents. The DSM-5 is considered one of the principal guides of psychiatry, along with the International Classification of Diseases (ICD), Chinese Classification of Mental Disorders (CCMD), and the Psychodynamic Diagnostic Manual. However, not all providers rely on the DSM-5 as a guide, since the ICD's mental disorder diagnoses are used around the world and scientific studies often measure changes in symptom scale scores rather than changes in DSM-5 criteria to determine the real-world effects of mental health interventions.

A mental disorder, also referred to as a mental illness, a mental health condition, or a psychiatric disorder, is a behavioral or mental pattern that causes significant distress or impairment of personal functioning. A mental disorder is also characterized by a clinically significant disturbance in an individual's cognition, emotional regulation, or behavior, often in a social context. Such disturbances may occur as single episodes, may be persistent, or may be relapsing–remitting. There are many different types of mental disorders, with signs and symptoms that vary widely between specific disorders. A mental disorder is one aspect of mental health.

Anti-psychiatry, sometimes spelled antipsychiatry without the hyphen, is a movement based on the view that psychiatric treatment is often more damaging than helpful to patients, highlighting controversies about psychiatry. Objections include the reliability of psychiatric diagnosis, the questionable effectiveness and harm associated with psychiatric medications, the failure of psychiatry to demonstrate any disease treatment mechanism for psychiatric medication effects, and legal concerns about equal human rights and civil freedom being nullified by the presence of diagnosis. Historical critiques of psychiatry came to light after focus on the extreme harms associated with electroconvulsive therapy or insulin shock therapy. The term "anti-psychiatry" is in dispute and often used to dismiss all critics of psychiatry, many of whom agree that a specialized role of helper for people in emotional distress may at times be appropriate, and allow for individual choice around treatment decisions.

<span class="mw-page-title-main">Hypochondriasis</span> Medical condition

Hypochondriasis or hypochondria is a condition in which a person is excessively and unduly worried about having a serious illness. Hypochondria is an old concept whose meaning has repeatedly changed over its lifespan. It has been claimed that this debilitating condition results from an inaccurate perception of the condition of body or mind despite the absence of an actual medical diagnosis. An individual with hypochondriasis is known as a hypochondriac. Hypochondriacs become unduly alarmed about any physical or psychological symptoms they detect, no matter how minor the symptom may be, and are convinced that they have, or are about to be diagnosed with, a serious illness.

In medicine, comorbidity—from Latin morbus ("sickness"), co ("together"), -ity —is the presence of one or more additional conditions often co-occurring with a primary condition. Comorbidity describes the effect of all other conditions an individual patient might have other than the primary condition of interest, and can be physiological or psychological. In the context of mental health, comorbidity often refers to disorders that are often coexistent with each other, such as depression and anxiety disorders. The concept of multimorbidity is related to comorbidity but presents a different meaning and approach.

Abnormal psychology is the branch of psychology that studies unusual patterns of behavior, emotion, and thought, which could possibly be understood as a mental disorder. Although many behaviors could be considered as abnormal, this branch of psychology typically deals with behavior in a clinical context. There is a long history of attempts to understand and control behavior deemed to be aberrant or deviant, and there is often cultural variation in the approach taken. The field of abnormal psychology identifies multiple causes for different conditions, employing diverse theories from the general field of psychology and elsewhere, and much still hinges on what exactly is meant by "abnormal". There has traditionally been a divide between psychological and biological explanations, reflecting a philosophical dualism in regard to the mind-body problem. There have also been different approaches in trying to classify mental disorders. Abnormal includes three different categories; they are subnormal, supernormal and paranormal.

Schizoaffective disorder is a mental disorder characterized by abnormal thought processes and an unstable mood. This diagnosis requires symptoms of both schizophrenia and a mood disorder: either bipolar disorder or depression. The main criterion is the presence of psychotic symptoms for at least two weeks without any mood symptoms. Schizoaffective disorder can often be misdiagnosed when the correct diagnosis may be psychotic depression, bipolar I disorder, schizophreniform disorder, or schizophrenia. This is a problem as treatment and prognosis differ greatly for most of these diagnoses.

Historically, mental disorders have had three major explanations, namely, the supernatural, biological and psychological models. For much of recorded history, deviant behavior has been considered supernatural and a reflection of the battle between good and evil. When confronted with unexplainable, irrational behavior and by suffering and upheaval, people have perceived evil. In fact, in the Persian Empire from 550 to 330 B.C., all physical and mental disorders were considered the work of the devil. Physical causes of mental disorders have been sought in history. Hippocrates was important in this tradition as he identified syphilis as a disease and was, therefore, an early proponent of the idea that psychological disorders are biologically caused. This was a precursor to modern psycho-social treatment approaches to the causation of psychopathology, with the focus on psychological, social and cultural factors. Well known philosophers like Plato, Aristotle, etc., wrote about the importance of fantasies, dreams, and thus anticipated, to some extent, the fields of psychoanalytic thought and cognitive science that were later developed. They were also some of the first to advocate for humane and responsible care for individuals with psychological disturbances.

Hypersomnia is a neurological disorder of excessive time spent sleeping or excessive sleepiness. It can have many possible causes and can cause distress and problems with functioning. In the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), hypersomnolence, of which there are several subtypes, appears under sleep-wake disorders.

Cognitive disorders (CDs), also known as neurocognitive disorders (NCDs), are a category of mental health disorders that primarily affect cognitive abilities including learning, memory, perception, and problem-solving. Neurocognitive disorders include delirium, mild neurocognitive disorders, and major neurocognitive disorder. They are defined by deficits in cognitive ability that are acquired, typically represent decline, and may have an underlying brain pathology. The DSM-5 defines six key domains of cognitive function: executive function, learning and memory, perceptual-motor function, language, complex attention, and social cognition.

In medicine and medical anthropology, a culture-bound syndrome, culture-specific syndrome, or folk illness is a combination of psychiatric and somatic symptoms that are considered to be a recognizable disease only within a specific society or culture. There are no objective biochemical or structural alterations of body organs or functions, and the disease is not recognized in other cultures. The term culture-bound syndrome was included in the fourth version of the Diagnostic and Statistical Manual of Mental Disorders which also includes a list of the most common culture-bound conditions. Counterpart within the framework of ICD-10 are the culture-specific disorders defined in Annex 2 of the Diagnostic criteria for research.

Medical model is the term coined by psychiatrist R. D. Laing in his The Politics of the Family and Other Essays (1971), for the "set of procedures in which all doctors are trained". It includes complaint, history, physical examination, ancillary tests if needed, diagnosis, treatment, and prognosis with and without treatment.

The biopsychiatry controversy is a dispute over which viewpoint should predominate and form a basis of psychiatric theory and practice. The debate is a criticism of a claimed strict biological view of psychiatric thinking. Its critics include disparate groups such as the antipsychiatry movement and some academics.

The classification of mental disorders, also known as psychiatric nosology or psychiatric taxonomy, is central to the practice of psychiatry and other mental health professions.

Child and adolescent psychiatry is a branch of psychiatry that focuses on the diagnosis, treatment, and prevention of mental disorders in children, adolescents, and their families. It investigates the biopsychosocial factors that influence the development and course of psychiatric disorders and treatment responses to various interventions. Child and adolescent psychiatrists primarily use psychotherapy and/or medication to treat mental disorders in the pediatric population.

<span class="mw-page-title-main">Psychiatry</span> Branch of medicine devoted to mental disorders

Psychiatry is the medical specialty devoted to the diagnosis, prevention, and treatment of deleterious mental conditions. These include various matters related to mood, behaviour, cognition, and perceptions.

<span class="mw-page-title-main">Iatrogenesis</span> Causation of harm by any medical activity

Iatrogenesis is the causation of a disease, a harmful complication, or other ill effect by any medical activity, including diagnosis, intervention, error, or negligence. First used in this sense in 1924, the term was introduced to sociology in 1976 by Ivan Illich, alleging that industrialized societies impair quality of life by overmedicalizing life. Iatrogenesis may thus include mental suffering via medical beliefs or a practitioner's statements. Some iatrogenic events are obvious, like amputation of the wrong limb, whereas others, like drug interactions, can evade recognition. In a 2013 estimate, about 20 million negative effects from treatment had occurred globally. In 2013, an estimated 142,000 persons died from adverse effects of medical treatment, up from an estimated 94,000 in 1990.

Somatic symptom disorder, also known as somatoform disorder, is defined by one or more chronic physical symptoms that coincide with excessive and maladaptive thoughts, emotions, and behaviors connected to those symptoms. The symptoms are not deliberately produced or feigned, and they may or may not coexist with a known medical ailment.

A medical condition is termed heterogeneous, or a heterogeneous disease, if it has several etiologies ; as opposed to homogeneous conditions, which have the same root cause for all patients in a given group. Examples of heterogeneous conditions are hepatitis and diabetes. Heterogeneity is not unusual, as medical conditions are usually defined pathologically, as in "liver inflammation", or clinically, as in "excessive urination", rather than etiologically. Heterogeneous conditions are often divided into endotypes based on etiology.

References

  1. ↑ Chiong, Winston (2001). "Diagnosing and defining disease". JAMA. doi:10.1001/jama.285.1.89-JMS0103-2-1.
  2. ↑ Kulkarni, Abhaya V. (2005). "The challenges of evidence-based medicine: A philosophical perspective". Medicine, Health Care and Philosophy. 8 (2): 255–260. doi:10.1007/s11019-004-7345-8. PMID   16215804.
  3. ↑ Greenhalgh, Trisha (2012). "Why do we always end up here? Evidence-based medicine's conceptual cul-de-sacs and some off-road alternative routes". Journal of Primary Health Care. 4 (2): 92–7. doi: 10.1071/HC12092 . PMID   22675691.
  4. ↑ Wieringa, Sietse; Engebretsen, Eivind; Heggen, Kristin; Greenhalgh, Trish (2017). "Has evidence-based medicine ever been modern? A Latour-inspired understanding of a changing EBM". Journal of Evaluation in Clinical Practice. 23 (5): 964–970. doi:10.1111/jep.12752. PMC   5655926 . PMID   28508440.
  5. ↑ Loughlin, Michael; Lewith, George; Falkenberg, Torkel (2013). "Science, Practice and Mythology: A Definition and Examination of the Implications of Scientism in Medicine". Health Care Analysis. 21 (2): 130–145. doi:10.1007/s10728-012-0211-6. PMID   22622355.
  6. ↑ Freedman, Lewis (2013). "The Initial Field Trials of DSM-5: New Blooms and Old Thorns". American Journal of Psychiatry. doi:10.1176/appi.ajp.2012.12091189.
  7. ↑ Green, Richard (2002). "Is pedophilia a mental disorder?". Archives of Sexual Behavior . doi:10.1023/a:1020699013309. PMID   12462476.
  8. ↑ Widiger, T. (2000). "Adult Psychopathology: Issues and Controversies". Annual Review of Psychology. doi:10.1146/annurev.psych.51.1.377.
  9. ↑ "Striving for Coherence: Psychiatry's Efforts over classification". JAMA. 2005. doi:10.1001/jama.293.20.2526. PMID   15914753.
  10. ↑ Martin, Elizabeth A. (2010). "Idiopathic". Concise Medical Dictionary (8th ed.). doi:10.1093/acref/9780199557141.001.0001. ISBN   9780199557141 . Retrieved 2019-01-04.
  11. ↑ Clark, Danielle. "Aggressive periodontitis: The unsolved mystery" (PDF). Quintessence International. doi:10.3290/j.qi.a37387.
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