Affective Disorders
≈ Depression:
– “Common cold of mental illness” most widespread psychological disorder
– One in ten chance of at least one depressive episode of clinical proportions
– All population groups vulnerable
– One in 20 visits to doctor due to depression
– >100 depressed patients per doctor’s list, but half unrecognised
– 20% develop chronic depression
– Patients not mention depression: embarrassment, stigma, avoid lack of sympathy
– Affective disorders are associated with creativity (Adaptive upsides)
≈ Symptoms of Depression:
1. Mood/emotional symptoms (constant sadness, irritability, loss of interest)
2. Thought/cognitive symptoms (Negative/distorted thinking, decreased RT)
3. Motivational symptoms
4. Somatic/physical symptoms (slower movement/speaking, lack of energy)
≈ Classification of Depression:
– Unipolar:
Depression mixed and highly correlated with anxiety
Depressive episode (single)
Recurrent depressive (numerous)
Dysthymia persistent & mild (depressive personality) – always feeling low
– Bipolar:
Bipolar affective disorder with manic episodes
Switching between manic and depressive episodes
Cyclothymia persistent instability of mood – mild cycling between mania and
depression
≈ Brain areas involved in depression:
– Decreased activity in nuc. Accumbens (reward and taking pleasure in things)
– The longer people with depression go untreated the more their hippocampal
volume decreases (Sheline et al 2003)
– Increased metabolic activity in amygdala (emotion regulation) and orbitofrontal
cortex in people with depression
–
≈ Heritability of depression:
– Sullivan et al. (2000):
Greater than 0 liability in heritability in twins
Some differences between males and females
– Bertelsen (1977):