Affective Disorders (Neuroscience & Behaviour) With extra reading

Affective Disorders
Depression
 Widespread– 1 in 10 people
 All people are vulnerable
 20% develop chronic depression
 Stigma – embarrassing, avoiding lack of sympathy, so figures are probably higher than reported
 4 sets of symptoms
- Mood/emotional
- Thought/ cognitive – disorganised thoughts
- Motivational
- Somatic /physical – disturbed sleep, aches and pains.

Unipolar – dysthymia ( depressive personality), mixed depression and anxiety, single/numerous
depressive episodes.

Bipolar – cyclothymia – persistent instability of mood – instable. Manic episodes, similar to SZ?

 Famous artists, bipolar disorder linked to creativity – higher rates of all mood disorders in
artists, poets.
 Age of onset – increase in cumulative frequency rates 1905 – 1955
 Genetics – MZ twins higher concordance rates than DZ twins
- Higher for bipolar
- Not 100% - so interaction of environment.

Treatment-

 Lithium – treatment for manic episode – time between episodes greater on lithium (9 years
compared to one year for placebo)
 Carbamazepine also used but less effective
 Noradrenalin, Serotonin ( raphe nuclei- project to lots of brain region. 5HT system critically
involved in anxiety, sleep etc, aggression – so can caused symptoms of unipolar depression)
 Anti-depressants work on reuptake of noradrenalin, serotonin.
 Current pharmacology – serotonin reuptake inhibitors - fluoxetine (Prozac), sertraline.
- But difficulty coming off the drugs
 Electric shocks used in the past, quite effective.
 MAOI – interact with lots of food – can’t eat wheat/cheese.
 5HT2 receptor linked to anxiety, sleep
 Monoamine theory of Depression – due to depletion of monamines NA, 5HT, DA
- Antidepressants act through these
- But too simplistic
- Anti-depressants have a delayed effect – but they should rebalance monoamine
immediately – so why don’t symptoms go away immediately?
 Noradrenalin – catecholamines