☆ Schizophrenia

Positive symptoms of schizophrenia

• Reality distortion

• Hallucinations

• Delusions

• Thought disorder.

Negative symptoms of schizophrenia

• Self-neglect

• Social withdrawal

• Decreased emotion

• Apathy

• Poverty of speech

Neurotransmitter systems implicated in the etiology of schizophrenia

• Dopaminergic neurotransmission

• Glutamatergic neurotransmission.

Changes in dopaminergic activity in schizophrenia

• Hyperactivity of mesolimbic dopamine neurons (positive symptoms)

• Hypoactivity of mesocortical dopamine neurons (negative symptoms)

Relationship between cannabis use and schizophrenia

Daily use of high-potency cannabis is associated with a fivefold increase in developing psychosis.

Common side effects of antipsychotic medications

• Extrapyramidal symptoms

• Akathisia

• Tardive dyskinesia

• Pseudo-parkinsonism.

Receptors targeted by antipsychotic drugs

Primarily Dopamine D2 receptors.

Hypo-functional neurotransmitter in schizophrenia

Glutamate.

Drugs known to induce psychosis

NMDA receptor antagonists like ketamine and phencyclidine.

Changes in brain structure associated with schizophrenia

• Reduced volume of the hippocampus

• Enlarged ventricles

• Reduced temporal lobe.

Brain structure abnormalities present at onset (developmental not degenerative)

Effects of the antipsychotic drug chlorpromazine

• Apathy

• Reduced emotion

• Aggression

• Potential extrapyramidal effects.