Early ideas about mental illness were connected with religious beliefs. People who behaved abnormally were thought to be possessed by gods or demons. As time passed, mental illness began to be viewed as a moral defect. Beginning around the 16th century, people with mental illnesses were confined in asylums (institutions for people with mental disorders) with other "undesirables."In asylums many patients were subjected to cruel treatments until the 20th century. Treatments included painful restraints, ice baths, and being wrapped in wet sheets. Lobotomies, surgeries to destroy the prefrontal cortex of the brain, were commonly performed until the 1970s. Many patients were overmedicated with sedating drugs and forced to take drugs or have shock treatments against their will. Hospitals for people with mental illness have greatly improved. However, not all people who need treatment for serious mental illness are able to access treatment consistently. About half of the U.S. inmate population meets criteria for a mental health problem, and about a quarter of people experiencing homelessness have a serious mental illness. Better treatment of mental health problems may help reduce rates of incarceration and homelessness.
Prevalence of Psychological Disorders
Drawing the line between normal and abnormal thoughts and feelings can be difficult. People often experience intense negative emotions or have periods of sadness or worry. Having strong feelings in response to difficult life events, such as a death or divorce, is entirely normal. A psychological disorder is a prolonged or recurring problem that causes significant distress or interferes with a person's ability to function adequately as a member of a community. Psychological disorders are characterized by problematic thoughts, behaviors, or feelings. They are disorders of the mind that may have physical or environmental causes. Although many psychological disorders have clear physical causes, just like diseases such as diabetes or heart disease, psychological disorders carry more stigma than other medical problems. Shame and the inaccurate belief that mental disorders reflect personal weakness can prevent people from seeking treatment.
In casual speech, people use the term insane as if it means any serious mental problem. However, the term has a very specific meaning. Insanity is a legal term meaning a defendant could not differentiate between right and wrong at the time of the crime due to a mental disease or defect. On rare occasions when criminal defendants are judged as insane, they may be sentenced to mental health facilities rather than correctional facilities.
Classification and Diagnosis
A clinical diagnosis in medicine involves observing symptoms and matching them to a particular illness. The same process is used to match psychological disorders to symptoms. The Diagnostic and Statistical Manual of Mental Disorders (DSM) is a manual commonly used in the United States to classify psychological disorders. This manual describes symptoms for each disorder and details the number of symptoms and duration of symptoms required for each diagnosis. This text is produced by the American Psychiatric Association based on expert input from psychiatrists and psychologists who conduct research and provide treatment. Since its first publication in 1952, the DSM has undergone many revisions to stay up to date with current knowledge about the causes and symptoms of disorders. The number of identified disorders has expanded greatly since the first edition. The first edition of the DSM provided very subjective descriptions of each disorder. This meant that mental health professionals would often disagree about which diagnosis best fit an individual patient. Revisions to the DSM focused on making descriptions of disorders concrete and focused on easily observable symptoms. This has made it more likely that professionals will agree on diagnoses. The DSM-5, published in 2013, lists symptoms and diagnostic criteria for over 150 disorders. It also presents information about potential causes and describes each disorder's prevalence, the rate of occurrence within the population.
The DSM has created a shared language among clinicians, but it still has some flaws. The DSM is based on the observations of Western clinicians, mostly living in the United States and Europe. Thus, the view of the DSM is embedded in the values and culture of people of European ancestry living in industrialized nations.
The DSM classification system draws a clear line between meeting and not meeting criteria for a disorder. Drawing a clear line often works well in medical contexts. For example, people either have a broken bone, or they do not. They either have strep throat, or they do not. Psychological disorders do not naturally have such clear distinctions. Disorders involve thoughts, feelings, and behaviors that are normal at low levels. For example, symptoms of major depressive disorder include sadness, irritability, fatigue, and feelings of worthlessness. Clinicians must make a judgment call about whether a person's distress is intense enough to count as a symptom. It is difficult to know where to draw the line between normal and atypical levels of sadness. Many clinicians and researchers think it makes more sense to view distress and disordered behavior along a continuum of severity rather than simply a disordered/not-disordered distinction. This problem can become especially clear when a person falls just below the cutoff for a disorder. For example, in the DSM-5 a diagnosis of major depressive disorder requires the presence of at least five symptoms lasting for at least two weeks. These means that technically a person who has been intensely sad, hopeless, and suicidal for 10 days but does not have other symptoms will not meet criteria for the diagnosis.
When the DSM was first written, people assumed psychological disorders were rare. However, with advances in psychiatric epidemiology (the study of rates and causes of psychological disorders), estimates of lifetime prevalence of mental illness have increased. About half of all Americans will suffer a psychological disorder in their lifetime. Fortunately, fewer people will suffer from a serious and long-lasting mental illness. Often, people with one mental health diagnosis also meet criteria for another diagnosis. Having more than one condition at a time is called comorbidity.