Psychology (Unipolar Depression: Biological explanation) Flashcards
Name DSM-V symptoms
Depressed mood most of the day.
Diminished interest or pleasure in all or most activities.
Significant unintentional weight loss or gain.
Insomnia or sleeping too much.
Agitation or psychomotor retardation noticed by others.
Fatigue or loss of energy.
Feelings of worthlessness or excessive guilt.
Diminished ability to think or concentrate, or indecisiveness.
Recurrent thoughts of death.
Name ICD-10 symptoms (difference between DSM and ICD outlined as well)
Reduced concentration and self-confidence.
Reduced self-esteem and self-confidence.
Ideas of guilt and unworthiness (even in a mild type of an episode).
Bleak and pessimistic views of the future.
Ideas or acts of self-harm or suicide;
Disturbed sleep.
Diminished appetite.
ICD has pessimistic views of the future, whereas DSM doesn’t have that - but does not really include social ideas linked to depression.
How do you get diagnosed with unipolar depression? (Both DSM and ICD
For both you need to have symptoms for two weeks to be diagnosed. DSM you need to have 5 and ICD 4 symptoms to get diagnosed
Name and outline the researchers who investigated the validity / reliability of diagnosis
Regier and Sartorius
Reports a kappa value (inter-rater reliability) of just 0.28 for major depressive disorder, one of the lowest figures of all recognized disorders. 31% of clinicians saying that it was a difficult diagnosis to make.
What is the biological explanation for Depression?
The monoamine hypothesis.
Monoamines are a group of neurotransmitters that regulate mood: they include serotonin, noradrenaline and dopamine.
serotonin is particularly important because it regulates the other neurotransmitters and without it, brain functioning becomes erratic.
Low levels of serotonin = dopamine levels drop (related to alertness and energy).
Low levels of serotonin = noradrenaline levels (related to mood and emotion) fluctuate more than they should.
High levels of serotonin would boost noradrenaline and dopamine, producing a hyper alert and psychotic state of mind. Linked to bipolar disorder.
Mao-a removes monoamine from the synapse (called re-uptake) and recylces neurotransmitters when they do not appear to be needed.
This is used as a basis for a lot of antidepressant drugs as they try to inhibit (reduce) the activity of MAO-A.
Evaluate the biological explanation in terms of positives
The monoamine hypothesis is backed up by the beneficial effects of drugs which boost monoamine activity (flooding the synapse with monoamines) or inhibit monoamine reuptake (preventing MAO-A from removing too many monoamines). Similarly, drugs that specifically prevent the reuptake of serotonin (SSRIs) reduce depressive symptoms.
Twin studies support it: Wender et al even states that people who don’t grow up around their genetically inherited depressive relatives, still show signs of it.
The 5-HTT gene that regulated serotonin, mostly causing inhibition (as Serotonin regulates the other neurotransmtters that are at work in the monoamine hypothesis)
Evaluate the biological explanation in terms of negatives.
Antidepressant drugs do not work for all patients. These drugs increase the levels of the monoamines immediately but can take weeks before the depressive symptoms fade, which challenges a direct link between neurotransmitters and depression.
Irving Kirsch in a 2008 study even showed that antidepressants to be little better than placebos (and even work as such at times).
The biological explanations are not complete explanations. For one thing, twin studies and adoption studies do not show 100% concordance in people with the same genes. This suggests that something non-biological is at work too, like the environment a person lives in. Making the biological explanation too reducitonistic.
The biological explanation is determinstic as well because it suggests that for people who have these biological factors it seems inevitable to avoid getting depressed. However, many studies show that not everyone with these predispositions gets depressed.
