Psychosis

Question 1

Is Schizophrenia a neurodegenerative disorder?

Answer 1

Schizophrenia is primarily considered a neurodevelopmental disorder, meaning it arises from abnormal brain development, often beginning in early life, even before symptoms appear in adolescence or early adulthood.

Some studies show progressive brain changes in people with schizophrenia (like reduced gray matter volume), leading some researchers to describe it as having neurodegenerative components

Question 2

What are the Neurodevelopmental etiologies of Schizophrenia?

Answer 2

1 Early Life Insults : genetic predisposing or environmental factors like obstetric complications or prenatal maternal infections
2 Disrupted Brain maturation : genetic or environmental cause related abnormalities in Synaptogenesis, Synaptic Pruning and White matter tract development
3 Progressive Brain Changes : Grey matter volume reduction and Lateral ventricular enlargement are some of the progressive brain changes observed in patients

Question 3

What is the role of dopamine in the etiology of Psychosis?

Answer 3

The dopamine hypothesis is a central tenet in the etiopathogenesis of psychotic disorders.
Hyperactivity of dopamine neurotransmission in subcortical regions is understood to cause positive symptoms.
This is supported by the efficacy of D2 R blockers.
Increased synaptic dopamine in striatum and associated regions is also thought to be involved.

Question 4

What are the neurobiologic mechanisms implicated in the etiopathogenesis of psychosis?

Answer 4

Along with the role of Dopamine, other mechanisms are
1 Glutamate and NMDA R hypo function
2 Serotonin : many SGAs affect 5HT Rs
3 GABA :altered GABA levels have been observed
4 ACh : the alpha 7 nicotinic ACh R is a potential therapeutic target
5 Aberrant functional connectivity in frontal and temporal networks
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