bio E Videbech and Ravnkilde. Flashcards
videbech and ravnkidle
hippocampal size and volume
aim
to compare hippocampal size and volume between depressed and non depressed patients
RM and participants
meta analysis
correlational
bipolar and unipolar depression
and healthy participants
randomly selected from record book
procedure
1) looked at brain scans
2) compared brain scans to see hippocampal volume and size.
results
depressed = smaller HC.
non depressed = relatively larger
bipolar and uni polar no sig diff BUT unipolar depression had smaller HC than bipolar.
implications
neurogenesis = reduced HC size cuz of higher stress and cortisol levels.
theory is valid - see diffs in size.
the results of this study show that….
depressed patients have less neural networks and connections in this hippocampus.
this is because….
chronic stress, associated with depression, increases cortisol levels, suppressing neurogenesis in the hippocampus and lead to the reduction of neurons over time. Elevated cortisol damages dendritic connections and inhibits the new making of neural cells, disrupting the brain’s ability to regenerate hippocampal tissue.
furthermore, a symptom of individuals w depression HPA axis H - have lower serotonin etc levels, which reduces/limits the effect of these neurotransmitters produced, further decreasing the neural connections and the passing of chemicals from one neuron to another, thus decreasing the HC size.
this shows that….
Depression may damage the structure of the hippocampus, a part of the brain involved in memory and focus, which could explain why people with depression often have trouble remembering things or concentrating
eval:
-:correlational no cause and effect
-: cross sectional - bad only one point in time
-: used precious data not reliable
-: other exV;s like treatment and daly life can impact
+: good number of participants
+: real life - high eco V (ppls acc had D)
+: high construct validity - random selection etc.
-: neuroplasticity may also play a role.
+: high replicability
