Mechanisms of psychotropic drug action

Question 1

what is schizophrenia?

Answer 1

• schizophrenia is a disease that is extreme in young patients.
• It starts in young adult life.
• It’s characterised by positive and negative symptoms.

Question 2

what are the postive symptoms of schizophrenia?

Answer 2

Delusions, Hallucinations and thought disorder

Question 3

what are the negative symptoms of schizophrenia?

Answer 3

Reduced speech
Lack of motivation
Reduced emotion
Social withdrawal

Question 4

which symptoms start first in schiophrenia? positive or negative?

Answer 4

symptoms often start positive then become negative

Question 5

what organ development is schiophrenia associated with?

Answer 5

The disease is mainly associated with the development of the brain

Question 6

what causes schizophrenia?

Answer 6

• cause is not yet known

- current evidence suggests genetic and environmental factors influence the disease

Question 7

what is the genetic component of schizophrenia?

Answer 7

Research shows theres a hereditary link and people that have is in their first degree family are susceptible to it.

Question 8

what is the environmental componet to schizophrenia?

Answer 8

Overuse of cannabis in teenage years may be linked to it.

Question 9

what is the key neurotransmitter in schizophrenia?(accoridng to the hypothesis)

Answer 9

dopamine

Question 10

what argument supports the dopamine hypothesis?

Answer 10

• scans show increased dopamine in schizophrenia patients.
• based on the hypothesis drugs have been developed that blcok dopamine recdptors (antipsychotics) and these restrict schizophrenia symptoms.
• Drugs that increase dopamine activity on the other hand such as- Amphetamine, Cocaine and L-dopa- can cause psychosis

Question 11

what argument go against the dopamine hypothesis?

Answer 11

• other neurotransmitters involved such as glutamate, can have a role in psychosis or a role in worsening symptoms.
• Environmental factors may play a role during brain development.
• If it was a neurotransmitter effect then antipsychotics shouldn’t take two weeks to work on symptoms. Instead their effect should be immediate.

Question 12

What are the causes of the underlying postive and negative symptoms?

Answer 12

Negative symptoms are linked to - increase in dopamine transmission. (Mesocortical pathway)
Positive symptoms are linked to - decrease in dopamine transmission. (Mesolimbic pathway)