Biological

Question 1

Andersen, et al (1994)

can be used on abnormal

Answer 1

Aim:

• The aim is to investigate self-efficacy and safety of selective serotonine reuptake inhibitor citalopram in treating post-stroke depression.

Design:

• Experimental method
• IV - SSRIs (they get the real treatment)
• DV - The Hamilton Depression Scale was used to measure amount of depression.
• Control group - sugar pills (Inert substance) placebo

Participants:

• 66 depressed, post-stroke, age 25-80,
• 2-25 weeks after stroke
• 33 people got placebo
• 33 people got citalopram

Procedure:

• 6 week double blind (neither researcher nor participants know who is in which condition)
• placebo- controlled trial was undertaken
  
  • one group is given the real treatment and another an inert substance.
• UKU side effect rating scale used to measure unwanted side effects

Results:

• The result of the study showed that, independent of medicine given, half of treated patients recovered within1 month, after have had a stroke after 2 to 6 weeks.
• no serious side effects
• direct link btw serotonin and depression.

Question 2

Baumgartner (2008)

Answer 2

Aim:

• To investigate the role of oxytocin after breaches of trust in a trust game

Design:

49 males – two group

• IV: oxytocin, via nasal spray
• DV: rate of trust
• fMRI
• Control group – placebo
• Correlation positive – the more you do something the more it increases something
• Trust game
  
  • 50% of game- trust broken by experimenter
  • P1 investor- sum of money- kept or share with turstee
  • if shared the sum was trippled (p2)
    
    • sum either kept (violoation of tust) or shared again (trust)
• Correlation – link between the hormone oxytocin and trust
• More of oxytocin the more of a trusting person you became

Results:

• Participants who were given a placebo prior to playing the game decreased their rate of trust (that is how much money they were willing to invest) after they discovered their trust had been violated.
• Participants who received oxytocin, however, continued to invest at similar rates regardless of whether or not their trusting behaviour had been take advantage of.
• Participants in the oxytocin group showed decreases in responses in the amygdala. This region is involved in emotional processing and is rich in oxytocin receptors.
• Even the caudate nucleus showed decreased responses – associated with learning and memory.
• The neural results observed were only apparent when participants played the trust game, but not the risk game.

Question 3

Caspi (2003)

Answer 3

Aim:

• To investigate the possible role of the 5-HTT gene in depression after experiences of stressful events.

Theory:

• 5-HTT gene encodes the serotonin transporter protein and is thus acitve in the serotonin nerve pathways.
• the pathways are involved in controlling mood, emotion, sleep, anxiety, agression
• the protein encoded by 5-HTT gene is responsible for the reuptake of serotonin in the presynaptic clee after it has been released in the synaptic cleft

Design:

• Researchers compared participants with a normal 5-HTT gene and mutation of the 5-HTT gebe with shorter alleles.
• both types are quite frequent in humans but the long alleles is slighly more frequent (57%) compared to the short allele (43%)
• when participants were 26 years ol, evaluated if htey had experienced one or multiple stressful events and then whether or not they developed depression
• depression after stress was then related to the participants genotype

Results:

• Individuals having two short forms of alleles were most likely to become depressed after stressful events

Evaluation:

• large population 43% and 57% carry the mutation it can be difficult to cocnlude that hte gene is a major contribution to depression.
• study shows a correlation but no cause and effect
• not clear how environmental factors affect genes. Is it stress that affects the gene or the gene that affects the stress?
• more reaserch is needed.