Negative Symptoms and Brain Damage

Question 1

While positive sxs are unique to schizo, negative and cognitive sxs are common to

Answer 1

many types of brain damage

Question 2

Behavioral evidence of abnormal brain development

Answer 2

1. Abnormal behavior before schizo sxs appear suggests abnormal brain fx’ing is present
2. in home movies of children who eventually grew up to be sch., they were judged to show more negative affect in facial expression and more abnormal movement than sibs

Question 3

CT studies

Answer 3

1. relative ventricular size of sch. s’s was more than twice the size of controls indicating enlarged ventricles and decreased brain substance

Question 4

Other evidence of brain abnormalities

Answer 4

1. MRI of monozygotic twins discordant for sch. – sch. sib showed:
   - larger lateral and 3rd ventricles
   - smaller anterior hippocampus
   - reduced total volume of L temporal gray matter

Question 5

Sxs usually first manifest in late adolescence or early adulthood…what happens later in life to cause onset?

Answer 5

1. what happens later in life to cause onset of sch.?
2. synapses increase up to age 5 and then decrease until early 20’s
   - maybe onset of sch. is related to this synaptic pruning
3. MRI evidence suggests sch. is not caused by a degenerative process like Alzheimer’s
4. rather rapid degeneration of brain occurs in young adulthood with little evidence of further degeneration
5. Serial MRI’s
6. Loss of cortical tissue twice as great in schizo s’s compared to controls
7. In monozygotic twins discordant for schizo, the affected twin had significantly greater gray matter loss, especially in the STG and DLPFC
8. Degeneration starts posteriorly and progresses anteriorly
9. Should schizo be considered a neurodegenerative disease?
   - It has many of the features of neurodegenerative dz