Mood Disorders Flashcards
Distinguish between the broad classes of mood disorders
Unipolar depressive disorders - Involve only depressive symptoms. E.g. MDD, persistent depressive disorder.
Bipolar Depressive Disorders - Both depressive and mania symptoms E.g. bipolar 1 and 2.
Describe some of the cardinal symptoms of mood disorders
- Profound sadness/guilt
- Anhedonia - Inability to experience pleasure
- Attentional deficits
- Insomnia
- Loss of interest
- Social withdrawal
Define the DSM-5 criteria for MDD
- Sad mood or loss of pleasure and 5 symptoms for at least 2 weeks
- Sleeping too much or too little
- Weight loss
- Loss of energy
- Feelings of worthlessness
- Difficulty concentrating
- Thoughts of death or suicide
Episodic disorder - Periods of depression which leave and then come back. Likely to return if happens once.
Define the DSM-5 criteria for persistent depressive disorder
Depressed mood for most of the day more than half of the time for 2yrs. At least two of these - Poor appetite or overeating - Sleeping too much or little - Low energy - Poor self-esteem - Trouble concentrating or decision making - Feelings of hopelessness
- Symptoms usually don’t clear for 2 months
- No manic periods
What is the lifetime prevalence of mood disorders?
- 10-20% of the general population experience MDD and 5% experience dysthymia
- Differs across cultures e.g. Kessler et al. (2005) 16.2% in the US meet the criteria for MDD at some point. Chang et al. (2008) - South Koreans more likely to describe a sad mood or suicidal thoughts compared to US.
- Twice as common in women than men
- Usually onsets in late teens to early 20s
- High comorbidity with other disorders
- Associated with other physical health problems
Explain the relationship between suicide and mood disorders
- 2% treated in outpatient setting will die by suicide
- 4% hospitalised
- 60% of those who commit suicide have a mood disorder
- Klein et al. (2007) - Those with dysthymia more likely to be hospitalised, attempt suicide and have impaired functioning compared to MDD
Explain some cardinal symptoms of bipolar disorders
- Intense elation or irritability
- Psychomotor agitation
- Extroverted behaviour
- Sociable to point of intrusiveness
- Excessive self-confidence
- Risky behaviours
- Surge in goal pursuit
Main defining symptom is manic symptoms which is a state of intense elation or irriability
Describe the different types of bipolar disorders
Bipolar 1 - At least one episode of mania in lifetime and episodes of depression
Bipolar 2 - At least one major depressive episode and one hypomania which is less severe than mania
Cyclothymia - Mild symptoms of depression and mania. Symptoms don’t reach full severity, 2yrs+
Hypomania - Less extreme, feel more social and productive. Change in functioning
Explain the DSM-5 criteria for manic and hypomanic episodes
Elevated or irritable mood and abnormally increased activity or energy.
At least 3 of these, 4 if mood is irritable
- Increase in goal-directed activity or psychomotor agitation
- Unusual talkativeness, rapid speech
- Racing thoughts
- Decreased need for sleep
- Incr self-esteem
- Attention easily diverted
- Excessive involvement in pleasurable activities likely to have painful consequences e.g. unwise business investments.
Manic episode
- Symptoms last 1 week, require hospitalization or include psychosis
- Symptoms cause significant distress or functional impairment
Hypomanic episode
- Symptoms last at least 4 days
- Changes in functioning observable to others, impairment not marked
- No psychotic symptoms
Explain the DSM-5 criteria for cyclothymic disorder
For at least 2yrs, 1yr in children
- Numerous periods with hypomanic symptoms that do not meet criteria for hypomanic episode
- Numerous periods with depressive symptoms that do not meet criteria for major depressive episode
Symptoms do not clear for more than 2m at a time.
Criteria for major depressive. manic or hypomanic episode have never been meet.
Symptoms can cause significant distress or functional impairment.
Describe the epidemiology of bipolar disorders
- Bipolar 1 = 0.6% of general population
- Bipolar 2 + Cyclothymia - 1-4%
- Usually seen before 25yrs
- Equally frequent in men and women but women experience more depressive episodes
- High rates of unemployment 80-90%
- Highest rates of suicide
- Dramatic reduction in life expectancy
Describe the etiology and relationship with genes in mood disorders
- MDD shows moderate heritability at .37 for identical twins.
- Difficult to identify specific genes and none have been found identified with MDD which is believed to be bc there are so many symptoms so caused by a set.
- Believed to be due to genes associated with the production of serotonin
- Bipolar heritability = .93
- Many overlap with schizophrenia
Explain how medications can be used in mood disorders
- Medications take 7-14 days to relieve symptoms
- Modern theories look at the sensitivity of postsynaptic receptors that respond to presence of neurotransmitter in synaptic cleft.
- Dopamine
- Depressed less responsive to drugs which include this
- Bipolar - Drugs that increase dopamine trigger mania symptoms. Suggests that dopamine receptors are overly sensitive.
What role do the neurotransmitters serotonin and dopamine play in the brain?
Serotonin - Mood regulation
Dopamine - Reward system
Explain the etiology of mood disorders in regards to abnormality within emotion and reward centres
- Abnormalities in blood-oxygenated flow
- Oversensitivity to emotional stimuli and difficulty regulating emotions
- There is also an impaired response to rewarding stimuli and a lack of motivation.
- But it is difficult to replicate these effects.
- Suggested that the amygdala is hyperactive to emotional stimuli in depression.
- Mayberg et al. (2005) - Planted electrodes in area next to subgenual anterior cingulate cortex of depressed. Reported feeling a relief of symptoms. Activity decreased.
- Hippocampus - Depressed report decreased activity when seeing emotional stimuli
