Mental Illness
Schizophrenia: “positive” symptoms:
• Disturbed form and content of thought
• Bizarre delusions
• Hallucinations (primarily auditory)
• Typically responsive to drugs
Schizophrenia: “negative” symptoms:
•Mood disorder with inappropriate affect
•Decrease in social function; withdrawal
•Motor alterations
•Do not respond as well to drugs
Two Major Stages of Schizophrenia
1. Acute phase: florid positive
symptoms; respond fairly well to
drugs; can go into remission.
2. Chronic phase: dominated by
negative symptoms; long course of
deterioration.
Fig. 21.11
Possible Causes of Schizophrenia
• Developmental defect?
• Physical loss of brain tissue?
• Hypofrontality? (decrease in frontal
cortex activity)
• Dopamine?
• [+ Serotonin Glutamate?]
“Normal” brain Schizophrenic brain
Fig. 21.12
Fig. 21.14
The Affective Disorders
• Monopolar: cyclic depression
separated by relatively normal periods
• Bipolar: alternations between
depression and mania
Symptoms of Depression
• Worse than occasional “blueness”
everyone feels at some point.
• Feelings of worthlessness, pessimism,
guilt, suicidal thoughts.
• Altered thinking patterns: slow labored
thought, inability to concentrate.
• Physical symptoms: insomnia, weight
loss, no appetite, increased sensitivity
to pain.
The Causes of Depression are
Probably Varied
• Most likely an imbalance in the
biochemical interactions in the brain,
rather than a single transmitter system.
• However, many studies focus on the
monoamines: NE and 5-HT in
particular.
– Depression associated with a functional
deficit of monoamine actions.
Types of Antidepressants
• MAO inhibitors: block monamine
oxidase.
• Tricyclics: block presynaptic transporter
responsible for reuptake of amines
(more NE than others).
• Serotonin-Selective Reuptake Inhibitors
(e.g. Prozac, Paxil, Zoloft)
• New- Selective 5-HT and NE reuptake
inhibitors.
Fig. 21.9
Bipolar Disorder
• Depressive phase similar to monopolar
depression.
• Interspersed with mania or hypomania
– Hypomania: elevated mood, often with
irritability or paranoia; increase in activity
and energy levels.
– Full Mania: goes “too far”- violent
agitation, bizarre behavior, delusional
thinking.
• Cyclothymia: abnormal mood swings,
but less severe than full bipolar.
Box 21.2 fig.
Fig. 21.10
Lithium and Bipolar Disorder
• Originally used to treat mania. No effect
on monopolar depression, but helps
stabilize both phases of bipolar.
• Major action thought to be to alter
second messenger metabolism in brain.
• Other drugs useful for mania only.
– Carbamazepine (adenosine antagonist)
– Valproate (enhances GABA function)