Schizophrenia

A mental disorder characterized by a fragmentation of cognitive processes and personality, resulting in a complex array of symptoms.

Symptoms that are present in individuals with schizophrenia, representing an excess or distortion of normal functions.

Symptoms that are present in individuals with schizophrenia, representing a decrease or loss of normal functions.

False perceptions that occur in the absence of an external stimulus.

Disorganized thoughts, speech, and behavior patterns, which may be difficult to follow or understand.

A range of behaviors that are repetitive, purposeless, and often unusual.

The concordance rate for monozygotic twins is 48%, suggesting a strong influence of genetics in schizophrenia.

The study of Tienari found that children adopted away from mothers with schizophrenia had an increased risk of developing the disorder, suggesting that environmental factors also play a role.

A scaffold protein implicated in the regulation of dopamine levels, a neurotransmitter crucial for motivation, reward, and behavior. Dysregulation of dopamine is linked to the development of schizophrenia.

An enzyme responsible for breaking down dopamine. Abnormalities in its activity can lead to an imbalance in dopamine levels, contributing to symptoms of schizophrenia.

A family of cell signaling proteins involved in the growth and development of neurons and their connections. Their role in regulating neuronal activity is crucial for brain function.

The period during which the brain undergoes significant developmental changes, with a heightened vulnerability to environmental influences. Schizophrenia onset is often linked to adolescence.

Stressful life events can trigger the development of schizophrenia or worsen existing symptoms. Particularly relevant are stressors during critical developmental periods.

The brain's response to stress through the release of cortisol. Individuals with schizophrenia display atypical cortisol responses, with potentially lower levels in saliva.

An enlargement of the ventricles, fluid-filled spaces in the brain, is sometimes observed in individuals with schizophrenia. This may be related to developmental disruptions.

A reduction in the size of the hippocampus, a brain structure crucial for memory and spatial navigation, is often seen in individuals with schizophrenia.

The brain structure involved in auditory processing and memory, which is smaller in individuals with schizophrenia.

A brain area that plays a crucial role in executive functions, planning, and decision-making. It is implicated in the negative symptoms of schizophrenia.

A group of brain structures that help to control movement and other functions, and are often targeted by antipsychotic medications. They are linked to the positive symptoms and motor problems in schizophrenia.

This theory suggests that schizophrenia is a result of a chemical imbalance in the brain, particularly concerning neurotransmitters like dopamine and glutamate.

A group of symptoms associated with abnormal increase in brain functions, such as hallucinations, delusions, and disorganized thinking.

A group of symptoms associated with reduced brain function, including flat affect, alogia, and avolition

The complex interaction between genetic predisposition and environmental factors in the development of schizophrenia.

Drugs that work by blocking dopamine receptors, often used to treat positive symptoms of schizophrenia.

A condition where individuals experiencing psychosis are prone to developing toxic psychosis as a result of amphetamine use.

A medication used to treat Parkinson's disease that can trigger psychotic episodes in some individuals.

A drug that increases dopamine turnover in the brain, suggesting it acts as a dopamine receptor antagonist.

The idea that schizophrenia arises from excessive dopamine activity in specific brain regions.

There is no consistent evidence supporting increased dopamine release in individuals with schizophrenia.

Studies on post-mortem brain tissue show increased D2 receptors in individuals with schizophrenia, possibly due to medication.

PET scans conducted on drug-naive patients with schizophrenia don't consistently reveal increased levels of D2 receptors.

Despite the dopamine hypothesis's prominence, conclusive evidence for increased dopamine signaling in schizophrenia remains elusive.

A gene implicated in schizophrenia, DISC1 is involved in neuronal migration and interacts with proteins mutated in lissencephaly, a condition characterized by a smooth brain surface.

The disruption of DISC1 leads to abnormal brain development, specifically affecting neuronal migration. This may be a contributing factor to schizophrenia.

This theory posits that an increase in neuregulin signalling contributes to schizophrenia, possibly by reducing the function of the NMDA glutamate receptor.

Atypical antipsychotic medication, Clozapine is known to be effective in treating schizophrenia symptoms by potentially acting on NMDA receptor function.

The brain's prefrontal cortex (PFC) is hypothesized to be hypofunctional in individuals with schizophrenia. This hypofunctionality is linked to negative symptoms.

Individuals with schizophrenia exhibit excessive activity in subcortical systems, potentially due to reduced inhibition from the hypofunctional prefrontal cortex. This is associated with positive symptoms.

Antipsychotic medications work by blocking dopamine receptors, particularly in subcortical areas. This helps to reduce the excessive activity associated with positive symptoms of schizophrenia.

Atypical antipsychotics, also known as second generation antipsychotics, are a class of medications used to treat schizophrenia and other mental disorders. Compared to older typical antipsychotics, they have a lower incidence of extrapyramidal side effects (EPS) like tremors and muscle stiffness, and are considered more effective at reducing negative symptoms like social withdrawal and apathy.

The receptor profile of a drug describes how it interacts with different receptors in the brain, influencing its effects and side effects. Clozapine, a typical antipsychotic, has a unique receptor profile with high affinity for serotonin receptors, which contributes to its lower EPS profile and efficacy in addressing negative symptoms.

DISC1 (Disrupted in Schizophrenia 1) is a gene implicated in schizophrenia. It's known to be a scaffold protein, meaning it interacts with other proteins to regulate their function.

COMT (Catechol-O-Methyl Transferase) is an enzyme that breaks down dopamine, a neurotransmitter involved in motivation and reward. The COMT gene has two variants, Val108 and Met108, which affect the enzyme's activity. While the Val108 variant is associated with schizophrenia and impaired cognitive function, the Met108 variant is associated with higher dopamine levels.

Neuregulin is a family of proteins involved in the development and function of neurons. Variations in Neuregulin genes have been linked to schizophrenia, suggesting they may contribute to the disorder's development.

Association with chromosomal microdeletion syndrome, a condition characterized by the deletion of a small part of a chromosome, and the identification of rare familial variants of schizophrenia have provided valuable insights into the genetic underpinnings of schizophrenia.

The dopamine hypothesis suggests that imbalances in dopamine levels play a central role in schizophrenia. While this hypothesis is still being studied, it provides a framework for understanding the disorder's pathophysiology and targeted treatments.

Genetics is a complex area of study, and while it is clear that genetics plays a role, multiple genes have been linked to susceptibility to schizophrenia. This suggests that a combination of genetic factors contributes to the disorder's development.