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.
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, 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.
A paraphilia is an experience of recurring or intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals. It has also been defined as a sexual interest in anything other than a consenting human partner. Paraphilias are contrasted with normophilic ("normal") sexual interests, though the definition of what makes a sexual interest normal or atypical remains controversial.
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.
The diagnostic category pervasive developmental disorders (PDD), as opposed to specific developmental disorders (SDD), was a group of disorders characterized by delays in the development of multiple basic functions including socialization and communication. It was defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM), and the International Classification of Diseases (ICD).
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.
Hypoactive sexual desire disorder (HSDD), hyposexuality or inhibited sexual desire (ISD) is sometimes considered a sexual dysfunction, and is characterized as a lack or absence of sexual fantasies and desire for sexual activity, as judged by a clinician. For this to be regarded as a disorder, it must cause marked distress or interpersonal difficulties and not be better accounted for by another mental disorder, a drug, or some other medical condition. A person with ISD will not start, or respond to their partner's desire for, sexual activity. HSDD affects approximately 10% of all pre-menopausal women in the United States, or about 6 million women.
Pervasive developmental disorder not otherwise specified (PDD-NOS) is a historic psychiatric diagnosis first defined in 1980 that has since been incorporated into autism spectrum disorder in the DSM-5 (2013).
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.
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.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), is the 2013 update to the Diagnostic and Statistical Manual of Mental Disorders, the taxonomic and diagnostic tool published by the American Psychiatric Association (APA). In 2022, a revised version (DSM-5-TR) was published. In the United States, the DSM serves as the principal authority for psychiatric diagnoses. Treatment recommendations, as well as payment by health care providers, are often determined by DSM classifications, so the appearance of a new version has practical importance. However, not all providers rely on the DSM-5 for planning treatment as 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. The DSM-5 is the only DSM to use an Arabic numeral instead of a Roman numeral in its title, as well as the only living document version of a DSM.
Behavioral addiction, process addiction, or non-substance-related disorder is a form of addiction that involves a compulsion to engage in a rewarding non-substance-related behavior – sometimes called a natural reward – despite any negative consequences to the person's physical, mental, social or financial well-being. In the brain's reward system, a gene transcription factor known as ΔFosB has been identified as a necessary common factor involved in both behavioral and drug addictions, which are associated with the same set of neural adaptations.
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 purposefully produced or feigned, and they may or may not coexist with a known medical ailment.
Bouffée délirante (BD) is an acute and transient psychotic disorder. It is a uniquely French psychiatric diagnostic term with a long history in France and various French speaking nations: Caribbean, e.g., Haiti, Guadeloupe, Antilles and Francophone Africa. The term BD was originally coined and described by Valentin Magnan (1835–1916), fell into relative disuse and was later revived by Henri Ey (1900–1977).
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.
Sexual masochism disorder (SMD) is the condition of experiencing recurring and intense sexual arousal in response to enduring moderate or extreme pain, suffering, or humiliation. The Diagnostic and Statistical Manual (DSM-5) of the American Psychiatric Association indicates that a person may have a masochistic sexual interest but that the diagnosis of sexual masochism disorder would only apply to individuals who also report psychosocial difficulties because of it.
This article discusses notable unsolved problems in medicine. Many of the problems relate to how drugs work, and to diseases with an unknown cause, the so-called idiopathic diseases.
Homosexuality was classified as a mental disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM) beginning with the first edition, published in 1952 by the American Psychiatric Association (APA). This classification was challenged by gay rights activists in the years following the 1969 Stonewall riots, and in December 1973, the APA board of trustees voted to declassify homosexuality as a mental disorder. In 1974, the DSM was updated and homosexuality was replaced with a new diagnostic code for individuals distressed by their homosexuality. Distress over one's sexual orientation remained in the manual, under different names, until the DSM-5 in 2013.
Immature personality disorder was a type of personality disorder diagnosis. It is characterized by lack of emotional development, low tolerance of stress and anxiety, inability to accept personal responsibility, and reliance on age-inappropriate defense mechanisms. The disorder has been "gaining prominence" in the 21st century. A study in Denmark found that together, these 6 "Other" types constituted 2.4% of all personality disorder diagnoses.
