Integrating Schizophrenia Theories

(See Figure 15.9)

• PFC is underactive (hypofrontality), perhaps because of abnormal brain development, negative symptoms produced

• PFC fails to excite DA neurons in the midbrain

• Underactive DA neurons in the midbrain create further underactity in the PFC; more negative symptoms are produced

• PFC fails to inhibit the release of dopamine in the nucleus accumbens, making this area overactive; positive symptoms are produced