essay plan for depression

Question 1

paragraph 1?

Answer 1

biological

• heritability estimate of around 40% (Kendler et al, 2006)
• candidate gene suggested as having short alleles for 5-HTTLPR gene which is associated with increased reactivity to events, experience higher levels of depression when coupled with a stressful event in children (Caspi et al, 2003) and adolescents (Vreshek-Schallhorn et al, 2014)
• ‘depression circuit’ suggested with increased activity in the amygdala and dorsal prefrontal cortex (Savitz et al, 2009) supported by TMS applied to areas in ‘depression circuit’ reducing symptoms in treatment resistant individuals, effect increased and maintained when applied to the dorsolateral prefrontal cortex, which implies it at least has a role in the maintainence of depression, or may causing it (Gross et al, 2007)
• increased reactivity to stress as shown by increased cortisol levels and dysregulaiton of the HPA axis found in depressed individuals, which is linked to also having the candidate gene (also deals with reactivity) (Stetler et al, 2011). elevated levels of cortiso can also lead to neural atrophy, especially in the hippocampus which plays a role in HPA inhibition, thus further dysregulating it, so becomes a cycle, and also negatively affects memory bias (Beck et al, 2016)

Question 2

paragraph 2?

Answer 2

parental mental health/parenting:

general finding that children with depressed mothers are more likely to have depression themselves - so suggestion that genetic vulnerability from mother and environmental vulnerability from mother

• 5 year olds had more depressive cognitions regarding theirselves (characteristic of depression) in a competitive game compared to controls (which may be linked to modelling or genetics or both causing it) (Murray et al, 2001) AND found that 20-41% of children and adolescents with depressed mothers have depression themselves (Goodman, 2007) in which the depression is longer, with earlier onset and causing more impairment (may be due to maintainence from mother)
• may be due to passing on elevated cortisol elvels, which accounts for 50% variances in fetal levels of cortisol (Field, 2002) so giving predisposition towards dysregulation and increased reactivity as previously discussed (atrophy) which is especially apparent when face-to-face with mother (Field, 1992). AND high cortisol levels&depression predicted depression (Essex et al, 2002)

influence which may explain the environmental link between depressed mother and depression: parenting style

• depressed mothers associated with negative parenting practice such as more negative perceotions of child, leading to negative self-evaluations and decreased self-worth of child, relating to depression (Goodman et al, 1994)
• equally, may be that mothers are inadequate socialising partners and so unable to get adequate social support which may enable resilience which not receiving from mother (Goodman , 2007)

so depressed mothers contribute to depression biologically, through genes and cortisol levels which transmit across the placenta and may predispose to increased stress levels, and also provide environmental vulnerability for depression through negative parenting lead to reduced self-worth of child and a lack of social support due to inadqeuate social partner so reduced chance for resilience

Question 3

paragraph 3?

Answer 3

cognitive biases serving to increase negative feelings in those vulnerable:

attentional - more founded in anxiety as finding that in emotional stroop task using neutral and negative emotional words, no significant difference in reaction times between the groups of words were found, suggesting not heavily attending to the negative words (Lim et al, 2005)
- however, finding that depressed individuals are more sensitive to negative feedback, shown through increased error-related activity in ERP studies when negative evaluations, suggesting increased attention and processing, which may later contribute to the memory bias (Olvet et al, 2008)

interpretation - depressed participants make more negative interpretations of ambiguous stimuli (Lawson et al, 2002)

memory - strong negative bias for negative over positive events, filling memory with disproportionality large amount of negative compared to positive instances, as shown through an unusual memory bias for sad over happy faces (Ridout et al, 2003)

Question 4

discuss the aetiological factors of depression?

Answer 4

biological
heritable
candidate gene of 5HTTLPR linked to increased reactivity to stress, which links to increased cortisol levels from HPA dysfunction, which has a negative cycle as elevated levels increase atrophy in hippocampus which regulates HPA
increased activity in amygdala and dorsal prefrontal cortex known as ‘depression circuit’ and supported by TMS reducing treatment resistan depression, especially when applied to the dorsolateral prefrontal cortex

parental
maternal depression as a biological cause - cortisol levels in mother responsible for 50% of variance in fetus as pass through placenta and if higher levels then disposition for dysregulation and higher stress response in child (and negative cycle)
stats for link between maternal and child depression and longer and more damaging and link between high cortisol levels and maternal depression in predicting child depression

maternal depression as an environmental cause
linked to more negative parenting as more critical of child, leading to negative self-worth and evaluations (which may have links to cognitive biases later on)
also, inadequate social partners so lack social support which would act as a resilience factor against depression

cognitive biases
attentional bias not found in stroop task but found in brain study of more error-related activity for negative evaluations, so more sensitive to negative feedback, which may link to memory bias
found interpretation bias in that ambiguous situations will be interpreted negatively
memory bias for negative information, such as for sad faces over happy

so overall, vulnerability stems from biological or a negative life event as a child such as having a depressed mother, which is then driven into depression through the existence of cognitive biases worsening mood and distorting reality or reduced and critical social support from family