The term psychosis was first used in the medical literature by Ernest von Feuchtersleben in his textbook Principles of Medical Psychology (1847). Originally, the concept was defined broadly to include any impairment of the higher mental functions. Starting in the late 1800s, psychopathologists such as Emil Kraepelin, Eugen Bleuler, and Kurt Schneider began to differentiate specific psychotic disorders on the basis of their symptomatology and course. According to contemporary views, psychotic disorders are psychopathological conditions characterized primarily by profound disturbances in cognition, perception, emotion, and volition that result in severe psychosocial dysfunction, including inability to meet the demands of daily life, and impaired reality testing.
Symptomatology of Psychotic Disorders
Psychotic disorders comprise literally scores of symptoms, many of which have a variety of distinct manifestations. The symptoms are not specific and occasionally can be observed in other disorders, including cognitive disorders and mood disorders. Psychotic symptoms can be categorized into four broad categories, according to functional domain.
Disturbances of Cognition
These can be divided into disturbances of thought content (i.e., what a person thinks or talks about) versus disturbances of thought form (i.e., the way in which a person thinks or speaks). Symptoms related to thought content include delusions (beliefs held with certainty that are demonstrably false and culturally abnormal) and ideation (overvalued beliefs). Specific symptoms that occur with some frequency include thought insertion (others are placing thoughts in the person’s head), thought withdrawal (thoughts are being taken out of the person’s head), thought broadcasting (others can hear the person’s thoughts), misidentification (others are impersonating the person’s loved ones), and thoughts of reference (ordinary occurrences have a special meaning or were arranged just for the person). Disturbances of thought content are often characterized according to thematic content (e.g., persecutory, grandiose, erotomanic, jealous, somatic, or nihilistic) or according to whether they are bizarre (strange and impossible, totally implausible), fixed (stable over time), and systematized (complex and internally coherent).
Symptoms related to thought form include loose associations (jumping quickly from topic to topic), tangentiality (keeps wandering off the topic), circumstantiality (speech is only indirectly relevant to the topic being discussed), derailment (loses track of the topic completely), perseveration (keeps returning to the same topic), thought blocking (abruptly stops talking), neologisms (makes up new words), clanging (speech is full of rhymes), pressured speech (talks quickly and loudly), incoherence (speech is unintelligible), and echolalia (repeating words spoken by others).
Disturbances of Perception
These also can be divided into two major types. First, hallucinations are sensations in the absence of an external stimulus. They may occur in any sensory modality. The most common are auditory (e.g., hearing voices that other people can’t hear, often several people conversing in negative terms with or about the person or telling the person what to do) and visual (e.g., seeing things that other people can’t see, such as lurking strangers, ghosts, or visions). Second, depersonalization and derealization are abnormalities in perception of self and the environment, respectively. Depersonalization often involves “out-of-body” experiences (e.g., people perceive that their minds have left their bodies and are floating around the room or that they no longer have control over the movement of their own bodies). Derealization, in contrast, often involves the perception that the outside world is unreal or a sham (e.g., other people are automatons).
Disturbances of Emotion
These involve either the absence of normal affect or the presence of abnormal affect. Symptoms of the first type include blunted affect or poverty of affect (a restricted range and depth of emotional displays), anhedonia (loss of feelings of pleasure), and flat affect (near-complete absence of emotion). Symptoms of the second type include perplexity (confusion or uncertainty about what is going on), stormy affect (intense and labile emotions), incongruity (emotional displays that are apparently opposite to the tone of the topic being discussed), and silly affect (emotional displays that are unrelated to the topic being discussed and are often perceived as immature or juvenile).
Disturbances of Volition
These involve difficulties with voluntary, purposive behavior. Symptoms related to problems making plans and carrying out goal-directed activity include abulia or avolition (inactivity), apathy (ambivalence or loss of interest), anergia (loss of energy), autism or social withdrawal (failure to interact with other people), self-neglect (neglect of one’s own health and hygiene), negativism (ignoring the directions of others, resisting attempts to be moved by maintaining a rigid posture), and alogia or mutism (not speaking at all). Symptoms related to disturbance of behavioral tone, also known as catatonic symptoms, include hypertonia (overactivity, such as moving a lot or moving quickly) and hypotonia or catalepsy (underactivity, such as moving rarely, moving slowly, and waxy flexibility). Disturbances of purposeful activity include mannerisms (strange gestures or movements, such as walking on tiptoe or wiggling the fingers), stereotypies (repetitive, tic-like movements or vocalizations, such as constantly rubbing one’s head or barking like a dog), grimaces, posturing (assuming strange poses, such as standing with one leg in the air or sitting with arms extended), echopraxia (repeating the movements of others), and bizarre behavior (e.g., masturbating in public, eating inedible substances, playing with feces).
Clinical observation and research have found that certain psychotic symptoms frequently co-occur. There are at least three distinct syndromes (i.e., symptom clusters). Positive symp-toms are pathological by their presence—things such as delusions, hallucinations, stormy affect, and mannerisms. Negative symptoms are pathological by their absence; examples are poverty of speech, poverty of affect, and social withdrawal. Disorganization symptoms reflect impairment in the regulation or coordination of basic psychological functions— for example, incoherence, silly affect, and bizarre behavior.
Contemporary Classification of Psychotic Disorders
The classification of psychotic disorders is based on symptomatology, course, and etiology. In the fourth edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, or DSM-IV, psychotic disorders are grouped under the heading “Schizophrenia and Other Psychotic Disorders” and comprise a number of specific conditions.
Schizophrenia is characterized by a progressive or insidious onset (the prodromal phase), during which negative symptoms predominate presentation. This is followed after a period of months or even years by a period of acute exacerbation (the active phase) lasting a month or longer, during which positive and disorganization symptoms predominate. In the majority (about 80%) of cases the course is chronic, characterized by at least some persistent negative symptoms (the residual phase) as well as the occasional recurrence of positive or disorganization symptoms. The total duration of symptoms (prodromal plus active plus residual phases) should be at least 6 months. The symptoms should occur in the absence of prominent symptoms of depression or mania and should not be the result of substance intoxication or withdrawal or of general medical conditions. A number of commonly occurring subtypes of schizophrenia have been identified based on their primary symptomatology, including Paranoid Type (prominent delusions or hallucinations), Catatonic Type (prominent disturbances of volition), Disorganized Type (prominent disorganization symptoms), Residual Type (prominent negative symptoms), and Undifferentiated Type (doesn’t fit one of the other types). Age of onset is typically between 15 and 45 years; onset is about 5 years earlier in males than in females. Schizophrenia can have a debilitating affect on social adjustment, including impaired occupational functioning; failure to establish intimate relationships and reduced fertility; increased mortality owing to suicide, accident, and illness; and elevated risk of serious violence. In about 50% of cases, there is little or no improvement in social adjustment over time; in about 30%, there is substantial improvement; and in about 20%, there is good recovery or remission. Good prognosis is associated with having achieved adequate social functioning prior to onset of the disorder (e.g., absence of premorbid personality disorder), acute onset (e.g., short prodromal phase, onset following experience of a major life stressor), the presence of abnormal affect (e.g., stormy affect, perplexity, confusion), the absence of blunted or flat affect, and the absence of a family history of schizophrenia. Early detection and treatment may also be associated with good prognosis.
This differs from schizophrenia only with respect to its course. Whereas the total duration of symptoms in schizophrenia is at least 6 months, in schizophreniform disorder it is at least 1 month but less than 6 months. Two subtypes are recognized, With or Without Good Prognostic Features; the former may be associated with a full return to premorbid social functioning, whereas the latter may develop into full-blown schizophrenia (if psychotic symptoms persist or recur).
Brief Psychotic Disorder
This differs from schizophrenia and schizophreniform disorder in that the total duration of symptoms for all phases is less than 1 month, followed by a full return to premorbid social and occupational functioning. Three subtypes are recognized: Two subtypes, With and Without Marked Stressors, are diagnosed according to whether symptom onset occurs shortly after and apparently in response to stressful life events; the third, With Postpartum Onset, is diagnosed in women when symptom onset occurs within 4 weeks of giving birth.
This differs from schizophrenia only in that at some point during the active phase of the illness, the person also suffers from prominent symptoms of depression or mania (i.e., meets criteria for a major depressive, manic, or mixed episode) but has had a period of at least 2 weeks in which delusions or hallucinations were present in the absence of mood symptoms. Two subtypes are recognized, based on the nature of the mood symptoms: Bipolar Type, if the mood disturbance includes at least some symptoms of mania, and Depressive Type, if the mood disturbance is limited to symptoms of depression. Schizoaffective disorder is associated with a better long-term prognosis than schizophrenia, although with a worse prognosis than mood disorders such as major depressive disorder or bipolar I disorder.
This is characterized by prominent nonbizarre delusions that persist for at least 1 month. The person may also exhibit prominent olfactory or tactile hallucinations related to the content of the delusions. The delusions should occur in the absence of prominent auditory or visual hallucinations and the absence of prominent mood symptoms, and they should not be the result of substance intoxication or withdrawal or of general medical conditions. Seven subtypes are recognized, based on the predominant theme of the delusions: Erotomanic, Grandiose, Jealous, Persecutory, Somatic, Mixed, and Unspecified Type. Delusional disorder may cause only limited or restricted disturbance of psychosocial functioning.
Shared Psychotic Disorder
This is diagnosed when the person develops delusions similar to those exhibited by a close acquaintance who suffers from a psychotic disorder. The delusions should occur in the absence of prominent mood symptoms and should not be the result of substance intoxication or withdrawal or of general medical conditions.
Psychotic Disorder Due to a General Medical Condition
This is characterized by prominent delusions or hallucinations that arose during or shortly after and apparently in response to the physiological result of a general medical illness, which has been confirmed by history, physical examination, or laboratory findings. The symptoms should not occur only during periods of clouded consciousness (i.e., delirium). Two subtypes are recognized, With Delusions and With Hallucinations, based on which psychotic symptoms are predominant.
Substance-Induced Psychotic Disorder
This is identical to Psychotic Disorder Due to a General Medical Condition, except that history, physical examination, or laboratory findings indicate that the symptoms arose during or shortly after and apparently in response to substance intoxication or withdrawal. Two subtypes are recognized, With Onset During Intoxication and With Onset During Withdrawal.
Epidemiology of Psychotic Disorders
The lifetime prevalence of psychotic disorders in the general population is about 3% to 4%; the most common psychotic disorder is schizophrenia, with a lifetime prevalence of about 1% to 2%. Psychotic symptoms occur with much greater frequency; the lifetime prevalence of isolated delusions of hallucinations may be as high as 4% to 8%, and the lifetime prevalence of any psychotic symptom may be as high as 10% to 20%. The prevalence of psychotic disorders apparently varies little across nations, although within various nations, they may be diagnosed more often among members of ethnocultural minority groups and among recent immigrants. There is evidence of a small gender difference, with slightly higher rates among men than among women.
Etiology of Psychotic Disorders
Considerable research indicates the importance of neurobiological factors in the etiology of psychotic disorders, most likely as vulnerabilities or predisposing factors. Behavioral genetic studies indicate that psychotic disorders, and especially schizophrenia, are substantially heritable; however, molecular genetic studies have not been successful in isolating which genes, or even which chromosomes, are involved. The strength of the genetic contribution seems to vary as a function of the type of schizophrenia, with the strongest genetic loading associated with negative and disorganization symptoms. Many behavior geneticists agree that a polygenetic model is most likely, although there is also some support for a multifactorial model in which specific genes produce major effects and polygenes potentiate or insulate against the effects of the specific genes. Other studies have found that psychotic disorders are associated with a history of pregnancy and birth complications, including increased rates of maternal influenza in the second trimester, smoking and nutritional deprivation, and mother-child Rh incompatibility during pregnancy; obstetrical complications during delivery; and congenital abnormalities evident following delivery. Neuroimaging and postmortem studies have found an increased rate of structural brain abnormalities in people with psychotic disorders, as well as in their first-degree biologicalrelatives, including enlarged ventricular and sulcal spaces; decreased brain volume, especially in the frontal and temporal regions, thalamus, amygdale, and hippocampus; reduced inter-region connectivity; cytohistological abnormalities in the prefrontal and temporal regions, thalamus, hippocampus, and parahippocampal gyrus; and changes in regional activity during performance of cognitive tasks. Pharmacological studies indicate that disturbances of the dopaminergic neurotransmitter system in the brain (e.g., elevated frequency and activity of dopamine receptors) may be related to positive psychotic symptoms, whereas the serotonergic and glutamate systems may be related to both positive and negative symptoms.
Psychosocial factors may also be important in the etiology of psychotic disorders, most likely as triggers or precipitating factors. Life event studies indicate that active phases of psychotic disorders—both first episodes and recurrences—may occur shortly after, and apparently in reaction to, major life stressors. Also, a high level of negative expressed emotion in close per-sonal relationships is associated with increased risk for development of psychotic disorders, as well as the recurrence of active phases. Both these factors, however, may be of limited importance in the absence of a neurobiological vulnerability or predisposition.
Treatment of Psychotic Disorders
Pharmacological treatments have been used for more than 50 years during the active phase of psychotic disorders. In the 1950s through the 1970s, the mechanism of action of antipsychotic agents (e.g., phenothiazines, butyrophenones, thioxanthenes) was blockade of D2 dopamine receptors. These “typical” antipsychotics resulted in a substantial reduction of positive symptoms (and, to a lesser extent, disorganization symptoms) in about 60% of cases, limited reduction in about 30% of cases, and no response in about 10% of cases. Maintenance doses also helped reduce the recurrence of active phases. But typical antipsychotics had a minimal effect on negative symptoms and were associated with a high rate of serious side effects, including sedation and movement disorders. In the 1980s, “atypical” antipsychotics (e.g., clozapine, amisulpiride) were introduced. Their mechanism of action is more widespread than that of typical antipsychotics; they affect the serotonergic and adrenergic systems, in addition to the dopaminergic system. Atypical antipsychotics are at least as effective as typical antipsychotics in reducing positive symptoms (even in cases where typical antipsychotics are ineffective), and they may also reduce negative symptoms. They also have serious negative side effects, however, and are very expensive. The effectiveness of pharmacological treatment has greatly reduced the use of other, more invasive somatic treatment, such as electroconvulsive therapy and prefrontal lobotomy; it has also greatly reduced the frequency of long-term institutionalization.
Psychosocial interventions are frequently used to manage active symptoms, reduce active symptoms that are refractory to pharmacological treatment, improve social functioning following an active phase, and reduce the risk of recurrence. Institutionalization or respite care is used when it is difficult to deliver appropriate services in the community and when risk of suicide or violence is acute. Psycho-educational programs for patients and their families are used to improve compliance with other treatments and to reduce the rate of relapse. Cognitive behavioral therapy is used to manage active psychotic symptoms, such as delusions and hallucinations, as well as to improve compliance with other treatment. “Dual disorder” or “co-occurring disorder” programs are used to treat symptoms of substance use disorders in people who also suffer from psychotic disorders. Rehabilitation and social skills programs are used to improve interpersonal and occupational functioning.
Most often, treatment of psychotic disorders is long-term and multimodal: Pharmacological interventions are used in combination with one or more psychosocial interventions. Delivery of services may be most effective when coordinated using assertive case management techniques.
Forensic Relevance of Psychotic Disorders
In the law, competency to make important decisions typically requires that the person can accurately perceive the environment, rationally manipulate information about the environment, and communicate desires and intentions to others. These specific decision-making capacities may be impaired by the presence of psychotic symptoms, especially positive and disorganization symptoms. For this reason, psychotic disorders are particularly important in psycholegal evaluations of adjudicative competencies (e.g., stand trial, waive the right to counsel, confess) and culpability in criminal settings and evaluations of other competencies (e.g., consent to treatment, testify, make wills, sign contracts) in civil settings. For example, research on adjudicative competencies and culpability indicates that as many as 80% to 90% of people who are found legally incompetent, or nonculpable, may suffer from psychotic disorders or from other disorders (e.g., cognitive or mood disorders) with prominent psychotic symptoms.
With respect to the ability to control one’s behavior, the law typically requires that the person can freely form goals or intentions appropriate to the situation; develop plans to achieve those goals; and implement, evaluate, and modify those plans as necessary. These specific capacities also may be impaired by psychotic symptoms of all types. In criminal settings, psychotic disorders may be important in psycholegal evaluations of culpability and in civil matter evaluations of other competencies (e.g., consent to treatment, testify, make wills, sign contracts) in civil settings. In both criminal and civil settings, an issue of particular concern is serious violence associated with psychotic symptoms, particularly positive and disor-ganization symptoms. In some cases, the nature of the psychotic symptoms is directly related to the violence (e.g., a person with persecutory delusions assaults someone he believes is trying to poison him); in others, the psychotic symptoms interact with other factors (e.g., substance use) to generally destabilize social adjustment and increase interpersonal conflict that may result in violence. Research suggests that psychotic disorders cause a twofold increase in the odds that a person will engage in serious violence.
- Jibson, M. D., Glick, I. D., & Tandon, R. (2004). Schizophrenia and other psychotic disorders. Focus, 2, 17-30.
- Lieberman, J. A., Stroup, T. S., & Perkins, D. O. (Eds.). (2006). The American Psychiatric Publishing textbook of schizophrenia. Washington, DC: American Psychiatric Publishing.