Schizophrenia

Epidemiology and Etiology

Definition

Schizophrenia is a chronic serious mental disorder characterized by loss of contact with reality and manifested by two main symptoms: hallucinations and delusions.

• Should be distinguished from neuroses: less serious mental disorders that cause a sense of distress and deficit in functioning, and are characterized by anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder, depression, or other feelings of distress that are out of proportion to the circumstances of a person’s life
• Also commonly confused with dissociative identity disorder Dissociative identity disorder Dissociative identity disorder (DID) is a psychiatric condition marked by the presence of ≥ 2 distinct personality identities in a patient, with each personality having their own memories. The patient switches between personalities rapidly, especially under stress. It is associated with a history of childhood trauma or abuse. Dissociative Identity Disorder (DID), previously known as multiple personality disorder (MPD), or commonly called “split personality”

Epidemiology

• Affects 20 million people worldwide
• Lifetime prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency of approximately 0.50% in the United States and globally
• Men and women are equally affected, but with a slight difference in the age of onset
  • Men: average age of onset = 23 years 
  • Women: average age of onset = 26 years

Etiology

• No single etiological factor is responsible for schizophrenia, a syndrome comprising multiple diseases that present with similar signs and symptoms.
• The disorder manifests when a person with genetic predisposition is exposed to one of many environmental stressors.
• Genetic predisposition:
  • Affected first-degree relative = 10% risk
  • Affected monozygotic twin = 48% risk
  • Affected dizygotic twin = 14% risk
  • Offspring with 2 affected parents = 40% risk
• Environmental stressors are believed to be triggers of schizophrenia rather than true causes of the disorder.
  • Childhood trauma
  • Residence in an urban area
  • Social isolation
  • Frequent cannabis use in early adolescence 
  • Migration
  • Poverty
  • Stress and psychosocial factors 
  • Birth in late winter Winter Pityriasis Rosea or early spring
  • Advanced paternal age at conception

Pathophysiology

Genetic and environmental risk factors appear to act via a common pathway Common pathway Hemostasis of disrupting the function of 1 or more neurotransmitter components.

• Dopaminergic theory:
  • Almost all drugs with antipsychotic Antipsychotic Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics properties block the dopaminergic D2 receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors.
  • However, antipsychotics are only 70% effective and clozapine Clozapine A tricyclic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2a/2c receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent. Second-Generation Antipsychotics, the most effective antipsychotic Antipsychotic Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics for treating schizophrenia, is a weak D2 antagonist.
  • Hyperactivity Hyperactivity Attention Deficit Hyperactivity Disorder of dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS D2 receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors neurotransmission Neurotransmission The communication from a neuron to a target (neuron, muscle, or secretory cell) across a synapse. In chemical synaptic transmission, the presynaptic neuron releases a neurotransmitter that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across electrical synapses. Synapses and Neurotransmission in subcortical, and limbic brain Limbic brain The limbic system is a neuronal network that mediates emotion and motivation, while also playing a role in learning and memory. The extended neural network is vital to numerous basic psychological functions and plays an invaluable role in processing and responding to environmental stimuli. Limbic System: Anatomy regions contribute to the positive symptoms of schizophrenia.
  • Hypofunctionality of dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS D1 receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors neurotransmission Neurotransmission The communication from a neuron to a target (neuron, muscle, or secretory cell) across a synapse. In chemical synaptic transmission, the presynaptic neuron releases a neurotransmitter that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across electrical synapses. Synapses and Neurotransmission in the prefrontal cortex contributes to both negative and cognitive symptoms.
• Other theories:
  • Hypofunction of the N-methyl-D-aspartate (NMDA) glutamate Glutamate Derivatives of glutamic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure. Synthesis of Nonessential Amino Acids receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors  
  • Dysfunctional gamma-amino-butyric acid ( GABA GABA The most common inhibitory neurotransmitter in the central nervous system. Receptors and Neurotransmitters of the CNS) interneurons
  • Dysfunctional nicotinic acetylcholine Acetylcholine A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. Receptors and Neurotransmitters of the CNS receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors

Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with schizophrenia also have physical abnormalities of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification tissue, which can be seen in neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant studies. 

• Loss of cortical tissue volume, including the limbic system Limbic system The limbic system is a neuronal network that mediates emotion and motivation, while also playing a role in learning and memory. The extended neural network is vital to numerous basic psychological functions and plays an invaluable role in processing and responding to environmental stimuli. Limbic System: Anatomy, prefrontal cortex, thalamus Thalamus The thalamus is a large, ovoid structure in the dorsal part of the diencephalon that is located between the cerebral cortex and midbrain. It consists of several interconnected nuclei of grey matter separated by the laminae of white matter. The thalamus is the main conductor of information that passes between the cerebral cortex and the periphery, spinal cord, or brain stem. Thalamus: Anatomy, hippocampus, and amygdala Amygdala Almond-shaped group of basal nuclei anterior to the inferior horn of the lateral ventricle of the temporal lobe. The amygdala is part of the limbic system. Limbic System: Anatomy
• Ventricular enlargement (third and lateral)
• Decreased symmetry
• Hypoactivity of the frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy lobes and hyperactivity Hyperactivity Attention Deficit Hyperactivity Disorder of the basal ganglia Basal Ganglia Basal ganglia are a group of subcortical nuclear agglomerations involved in movement, and are located deep to the cerebral hemispheres. Basal ganglia include the striatum (caudate nucleus and putamen), globus pallidus, substantia nigra, and subthalamic nucleus. Basal Ganglia: Anatomy

Clinical Presentation

• Impairment of thoughts and affect, characterized by a distorted perception Perception The process by which the nature and meaning of sensory stimuli are recognized and interpreted. Psychiatric Assessment of reality
• The impairments are severe enough to affect the patient’s ability to participate in social events or to form relationships. 
• Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with schizophrenia often lack awareness about their illness ( insight Insight Psychiatric Assessment). 
• Co-existing substance use disorder and dependence is common (“dual diagnosis”).
• Symptoms can be classified into premorbid, positive, negative, and cognitive (see table below).

Mnemonic

To recall the negative symptoms of schizophrenia, remember the 5 As:

• Anhedonia
• Affect (flat)
• Alogia (poverty of speech)
• Avolition ( apathy Apathy Lack of emotion or emotional expression; a disorder of motivation that persists over time. Wernicke Encephalopathy and Korsakoff Syndrome)
• Attention (poor)

Diagnosis

Diagnosis is made by clinical observations based on the type of symptoms presented, their severity and duration, and how the patient’s life is affected by their presence.

• A total duration of symptoms of at least 6 months, including a period of positive symptoms lasting at least 1 month
• The presence of a mix of positive and/or negative symptoms, especially delusions, hallucinations, disorganized speech, or grossly disorganized or catatonic behavior
• The presence of these symptoms must disturb the patient’s daily functioning, including the social, personal, and professional areas of life. 
• Other conditions must be ruled out to make a definitive diagnosis:
  • Schizoaffective, brief psychotic, and schizoaffective disorders
  • Mood disorders (e.g., major depressive disorder Major depressive disorder Major depressive disorder (MDD), commonly called depression, is a unipolar mood disorder characterized by persistent low mood and loss of interest in association with somatic symptoms for a duration of ≥ 2 weeks. Major depressive disorder has the highest lifetime prevalence among all psychiatric disorders. Major Depressive Disorder, bipolar Bipolar Nervous System: Histology disorder)
  • Substance use disorder (requiring urine and blood toxicology tests)

Management and Prognosis

Pharmacological

Antipsychotic Antipsychotic Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics medications form the centerpiece of treatment for schizophrenia, especially the positive symptoms. Only caroprazine has been shown to have significant effects on negative symptoms. The choice of a specific agent is mostly based on the adverse effect profile, required route of administration, and the patient’s previous response to the drug. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship who respond usually show the most rapid improvement in the 1st 2 weeks and will often continue to improve during the following weeks. While there is a wide variety of mechanisms of action, most antipsychotics block postsynaptic dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors.

1st-generation antipsychotics ( FGAs FGAs Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics):

• Older medications (before 1989) 
• Dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS receptor Receptor Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors antagonist 
• Common side effects: EPS (which may become irreversible), hyperprolactinemia Hyperprolactinemia Hyperprolactinemia is defined as a condition of elevated levels of prolactin (PRL) hormone in the blood. The PRL hormone is secreted by the anterior pituitary gland and is responsible for breast development and lactation. The most common cause is PRL-secreting pituitary adenomas (prolactinomas). Hyperprolactinemia, neuroleptic malignant syndrome Neuroleptic malignant syndrome Neuroleptic malignant syndrome (NMS) is a rare, idiosyncratic, and potentially life-threatening reaction to antipsychotic drugs. Neuroleptic malignant syndrome presents with ≥ 2 of the following cardinal symptoms: fever, altered mental status, muscle rigidity, and autonomic dysfunction. Neuroleptic Malignant Syndrome, QT prolongation, sudden death, and an increased risk of mortality Mortality All deaths reported in a given population. Measures of Health Status in older adult patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with dementia Dementia Major neurocognitive disorders (NCD), also known as dementia, are a group of diseases characterized by decline in a person’s memory and executive function. These disorders are progressive and persistent diseases that are the leading cause of disability among elderly people worldwide. Major Neurocognitive Disorders
• Examples: haloperidol Haloperidol A phenyl-piperidinyl-butyrophenone that is used primarily to treat schizophrenia and other psychoses. It is also used in schizoaffective disorder, delusional disorders, ballism, and tourette syndrome (a drug of choice) and occasionally as adjunctive therapy in intellectual disability and the chorea of huntington disease. It is a potent antiemetic and is used in the treatment of intractable hiccups. First-Generation Antipsychotics, fluphenazine Fluphenazine A phenothiazine used in the treatment of psychoses. Its properties and uses are generally similar to those of chlorpromazine. First-Generation Antipsychotics, chlorpromazine Chlorpromazine The prototypical phenothiazine antipsychotic drug. Like the other drugs in this class chlorpromazine’s antipsychotic actions are thought to be due to long-term adaptation by the brain to blocking dopamine receptors. Chlorpromazine has several other actions and therapeutic uses, including as an antiemetic and in the treatment of intractable hiccup. First-Generation Antipsychotics

2nd-generation (atypical) antipsychotics ( SGAs SGAs Second-generation antipsychotics (SGA) are also called atypical antipsychotics. Medications in this class include aripiprazole, asenapine, brexpiprazole, cariprazine, clozapine, iloperidone, lumateperone, lurasidone, olanzapine, paliperidone, pimavanserin, quetiapine, risperidone, and ziprasidone. Second-Generation Antipsychotics):

• Newer medications, starting with clozapine Clozapine A tricyclic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2a/2c receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent. Second-Generation Antipsychotics (approved in 1989)
• Associated with a lower risk for EPS compared with FGAs FGAs Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics and therefore the 1st-line drugs to use (although the risk of metabolic syndrome Metabolic syndrome Metabolic syndrome is a cluster of conditions that significantly increases the risk for several secondary diseases, notably cardiovascular disease, type 2 diabetes, and nonalcoholic fatty liver. In general, it is agreed that hypertension, insulin resistance/hyperglycemia, and hyperlipidemia, along with central obesity, are components of the metabolic syndrome. Metabolic Syndrome is increased with SGAs SGAs Second-generation antipsychotics (SGA) are also called atypical antipsychotics. Medications in this class include aripiprazole, asenapine, brexpiprazole, cariprazine, clozapine, iloperidone, lumateperone, lurasidone, olanzapine, paliperidone, pimavanserin, quetiapine, risperidone, and ziprasidone. Second-Generation Antipsychotics)
• The decreased risk for EPS is the most important distinction from FGAs FGAs Antipsychotics, also called neuroleptics, are used to treat psychotic disorders and alleviate agitation, mania, and aggression. Antipsychotics are notable for their use in treating schizophrenia and bipolar disorder and are divided into 1st-generation antipsychotics (FGAs) and atypical or 2nd-generation antipsychotics. First-Generation Antipsychotics, as the pharmacologic properties, therapeutic effects, and adverse effects are not distinct between the 2 groups.
• Serotonin Serotonin A biochemical messenger and regulator, synthesized from the essential amino acid l-tryptophan. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Receptors and Neurotransmitters of the CNS and dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS antagonists 
• Common side effects: metabolic syndrome Metabolic syndrome Metabolic syndrome is a cluster of conditions that significantly increases the risk for several secondary diseases, notably cardiovascular disease, type 2 diabetes, and nonalcoholic fatty liver. In general, it is agreed that hypertension, insulin resistance/hyperglycemia, and hyperlipidemia, along with central obesity, are components of the metabolic syndrome. Metabolic Syndrome, hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension, sedation, anticholinergic Anticholinergic Anticholinergic drugs block the effect of the neurotransmitter acetylcholine at the muscarinic receptors in the central and peripheral nervous systems. Anticholinergic agents inhibit the parasympathetic nervous system, resulting in effects on the smooth muscle in the respiratory tract, vascular system, urinary tract, GI tract, and pupils of the eyes. Anticholinergic Drugs symptoms, hyperprolactinemia Hyperprolactinemia Hyperprolactinemia is defined as a condition of elevated levels of prolactin (PRL) hormone in the blood. The PRL hormone is secreted by the anterior pituitary gland and is responsible for breast development and lactation. The most common cause is PRL-secreting pituitary adenomas (prolactinomas). Hyperprolactinemia, EPS, cardiac effects, cardiomyopathies Cardiomyopathies A group of diseases in which the dominant feature is the involvement of the cardiac muscle itself. Cardiomyopathies are classified according to their predominant pathophysiological features (dilated cardiomyopathy; hypertrophic cardiomyopathy; restrictive cardiomyopathy) or their etiological/pathological factors (cardiomyopathy, alcoholic; endocardial fibroelastosis). Cardiomyopathy: Overview and Types, cataracts, and sexual dysfunction Sexual dysfunction Physiological disturbances in normal sexual performance in either the male or the female. Sexual Physiology
• Examples: risperidone Risperidone A selective blocker of dopamine D2 receptors and serotonin 5-HT2 receptors that acts as an atypical antipsychotic agent. It has been shown to improve both positive and negative symptoms in the treatment of schizophrenia. Second-Generation Antipsychotics, aripiprazole Aripiprazole A piperazine and quinolone derivative that is used primarily as an antipsychotic agent. It is a partial agonist of serotonin receptor, 5-HT1a and dopamine D2 receptors, where it also functions as a postsynaptic antagonist, and an antagonist of serotonin receptor, 5-HT2a. It is used for the treatment of schizophrenia and bipolar disorder, and as an adjunct therapy for the treatment of depression. Second-Generation Antipsychotics, quetiapine Quetiapine A dibenzothiazepine and antipsychotic agent that targets the serotonin 5-HT2 receptor; histamine h1 receptor, adrenergic alpha1 and alpha2 receptors, as well as the dopamine d1 receptor and dopamine D2 receptor. It is used in the treatment of schizophrenia; bipolar disorder and depressive disorder. Second-Generation Antipsychotics, olanzapine Olanzapine A benzodiazepine derivative that binds serotonin receptors; muscarinic receptors; histamine h1 receptors; adrenergic alpha-1 receptors; and dopamine receptors. It is an antipsychotic agent used in the treatment of schizophrenia; bipolar disorder; and major depressive disorder; it may also reduce nausea and vomiting in patients undergoing chemotherapy. Second-Generation Antipsychotics, ziprasidone Ziprasidone Second-Generation Antipsychotics, clozapine Clozapine A tricyclic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2a/2c receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent. Second-Generation Antipsychotics

Nonpharmacological (adjunct)

Nonpharmacological treatments are known to be partially effective in treating the negative and cognitive symptoms of the disorder and increase patient adherence to medications.

• Hospitalization Hospitalization The confinement of a patient in a hospital. Delirium:
  • May be required to ensure safety of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
  • In certain cases, isolation may be required for a short period of time.
• Psychosocial therapy:
  • Cognitive-behavioral therapy Cognitive-behavioral therapy Cognitive-behavioral therapy corrects faulty assumptions and tries to replace maladaptive behavior with healthier alternatives. Psychotherapy
  • Compliance Compliance Distensibility measure of a chamber such as the lungs (lung compliance) or bladder. Compliance is expressed as a change in volume per unit change in pressure. Veins: Histology therapy
  • Individual psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy
  • Group therapy Group therapy A form of therapy in which two or more patients participate under the guidance of one or more psychotherapists for the purpose of treating emotional disturbances, social maladjustments, and psychotic states. Psychotherapy
• Electroconvulsive therapy Electroconvulsive therapy Electrically induced convulsions primarily used in the treatment of severe affective disorders and schizophrenia. Major Depressive Disorder (ECT): mostly treatment-resistant cases for augmentation to pharmacotherapy

Prognostic factors

Differential Diagnosis

The following conditions are differential diagnoses for schizophrenia:

• Brief psychotic disorder Brief psychotic disorder Brief psychotic disorder is the presence of 1 or more psychotic symptoms lasting more than 1 day and less than 1 month. An episode is often stress-related with a sudden onset, and the patient fully returns to baseline functioning after an episode. Brief Psychotic Disorder: defined as the presence of one or more psychotic symptoms Psychotic symptoms Brief Psychotic Disorder lasting > 1 day and < 1 month. Characterized by a sudden onset, often with a specific trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation, and associated with a return to full function. The main distinguishing factor is the duration of symptoms.
• Schizophreniform disorder: a disorder in which the patient meets the criteria of schizophrenia, with symptoms lasting 1–6 months. The disorder has a much better prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas than schizophrenia. The main distinguishing factor is the duration of symptoms.
• Schizoaffective disorder Schizoaffective disorder Schizoaffective disorder is a mental disorder that is marked by 2 components: a psychotic component (hallucinations or delusions) and a mood component (mania or depression). Patients must therefore meet the diagnostic criteria for both major mood disorder and schizophrenia. Schizoaffective Disorder: a disorder with features of both affective disorders and schizophrenia. Symptoms of depression or mania Mania A state of elevated excitement with over-activity sometimes accompanied with psychotic symptoms (e.g., psychomotor agitation, inflated self esteem and flight of ideas). It is often associated with mental disorders (e.g., cyclothymic disorder; and bipolar diseases). Bipolar Disorder should be concurrent with features from the criterion of schizophrenia. Schizoaffective disorder Schizoaffective disorder Schizoaffective disorder is a mental disorder that is marked by 2 components: a psychotic component (hallucinations or delusions) and a mood component (mania or depression). Patients must therefore meet the diagnostic criteria for both major mood disorder and schizophrenia. Schizoaffective Disorder excludes patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with separate episodes of schizophrenia and affective disorders. It does, however, require a 2-week period whereby psychotic symptoms Psychotic symptoms Brief Psychotic Disorder exist in the absence of affective symptoms. 
• Delusional disorder Delusional disorder In delusional disorder, the patient suffers from 1 or more delusions for a duration of 1 month or more, without any other psychotic symptoms or behavioral changes and no decline in functioning abilities. Delusional Disorder: a disorder in which patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship suffer from 1 or more delusions for at least 1 month without any other psychotic symptoms Psychotic symptoms Brief Psychotic Disorder or behavioral changes and no decline in functioning abilities. 
• Substance-induced psychotic disorder: Alcohol, stimulants Stimulants Stimulants are used by the general public to increase alertness and energy, decrease fatigue, and promote mental focus. Stimulants have medical uses for individuals with ADHD and sleep disorders, and are also used in combination with analgesics in pain management. Stimulants, hallucinogens, and steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors can all prompt psychotic episodes. A detailed history relating to onset, duration, and cessation of symptoms in relation to drug or alcohol use must be taken.
• Psychotic disorder due to a general medical condition: Organic disorders of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification ( variant Creutzfeldt-Jakob disease Variant Creutzfeldt-Jakob Disease Transmissible Spongiform Encephalopathies, head injury, encephalitis Encephalitis Encephalitis is inflammation of the brain parenchyma caused by an infection, usually viral. Encephalitis may present with mild symptoms such as headache, fever, fatigue, and muscle and joint pain or with severe symptoms such as seizures, altered consciousness, and paralysis. Encephalitis, meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis, central nervous system Central nervous system The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges. Nervous System: Anatomy, Structure, and Classification tumors), as well as metabolic and endocrine disorders (Cushing’s syndrome, hyperthyroidism Hyperthyroidism Hypersecretion of thyroid hormones from the thyroid gland. Elevated levels of thyroid hormones increase basal metabolic rate. Thyrotoxicosis and Hyperthyroidism, hypernatremia Hypernatremia Hypernatremia is an elevated serum sodium concentration > 145 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled by the hypothalamus via the thirst mechanism and antidiuretic hormone (ADH) release. Hypernatremia occurs either from a lack of access to water or an excessive intake of sodium. Hypernatremia), can mimic symptoms of schizophrenia.
• Mood disorders with psychotic features: Psychotic features are mood-congruent and preceded by a clinical picture dominated by symptoms of a mood disorder, including major depressive disorder Major depressive disorder Major depressive disorder (MDD), commonly called depression, is a unipolar mood disorder characterized by persistent low mood and loss of interest in association with somatic symptoms for a duration of ≥ 2 weeks. Major depressive disorder has the highest lifetime prevalence among all psychiatric disorders. Major Depressive Disorder and bipolar Bipolar Nervous System: Histology disorder.