Mood disorders

• Mood disorders


  Range of disorders where disturbance of mood is key feature
• Mood disorders


  • Depression
  • Mania
• Depression


  Constant lows and sad state
• Mania


  Extreme feeling of euphoria or frenzied energy
• Mood disorders bring severe and long lasting psychological pain that gets worse over time
• MDD is the 2nd leading cause of disability worldwide (WHO 2008)
• 19.7% show symptoms of MDD (Evans, Macroy and Randall 2016)
• Women are 2x more likely to have MDD than men (Astbury 2010)
• Women aged 16-24 are at highest risk of MDD
• No gender differences in MDD for children
• 50% of MDD patients recover in 6 weeks without treatment
• 90% of MDD patients recover in 1 year without treatment
• 40% of MDD patients have at least one other episode later in life (Monroe 2010)
• Symptoms of MDD


  • Emotional: Anhedonia (loss of pleasure)
  • Motivation: 6-15% die by suicide
  • Behaviour: less active
  • Cognitive: negative views of self
  • Physical: headaches, dizziness, sleep/appetite changes
• Primary criteria for diagnosing MDD

  Needs to have a duration of 2 weeks or more and cannot be in response to something e.g. death
• Secondary criteria for diagnosing MDD

  No history of mania
• Biological causes of MDD

  • Genetics: Predisposed to develop MDD
  • Support: 20% of relatives have MDD, 10% of relatives have no diagnosis
  • Twin studies: 46% MZ, 20% DZ
  • Adoption studies: genetic basis for severe than mild MDD
  • Biochemical: Low serotonin and norepinephrine
  • Brain circuits: Prefrontal cortex, hippocampus, amygdala, Brodman area 25
• Electroconvulsive therapy


  1. Brain seizures (6-12 treatments)

  2. 50-80% relapse within 6 months

  3. Side effects: Short lasting cognitive problems, headaches, fatigue, permanent amnesia
• Factors considered in treatment

  • Severity
  • Side effects profile
  • Risk of overdoses
  • Other diagnoses e.g. Anxiety
• Medication may take up to 6 weeks to be maximally effective
• Efficacy of medication treatment is 60-80% overall
• Psychodynamic view


  Depression and grief have similar symptoms, introjection (merging of own identity with dead person) can lead to MDD, oral stage issues increase risk, symbolic or imagined loss can trigger MDD
• Early losses and inadequate parenting are not solely responsible for MDD, findings are inconsistent
• Behavioural view


  Depression arises from changes in rewards and punishments, reduced positive rewards leads to fewer constructive behaviours and spiral into depression
• Depressed people experience fewer social rewards than non-depressed people, the fewer rewards the more negative their mood
• Components of Beck's negative thinking model

  • Maladaptive attitudes developed in childhood
  • Negative thinking (cognitive triad)
  • Errors in thinking (arbitrary inferences)
  • Automatic negative thoughts
• Cognitive behavioural therapy is 50-60% effective and can show total elimination of MDD symptoms
• Learned helplessness


  People no longer have control over reinforcements in their lives and so don't try to help themselves, internal, global and stable attributions lead to greater feelings of helplessness
• Helplessness training in healthy people can induce significant symptoms of depression
• Bipolar disorder


  Characterized by experiencing lows of depression and highs of mania, affects 5 areas of functioning: emotional, motivational, behavioural, cognitive, physical
• Types of bipolar disorder

  • Bipolar I: Full manic and major depressive episodes
  • Bipolar II: Hypo-manic and major depressive episodes
• Lifetime risk of bipolar I is 1% for men and women, bipolar II is 0.5% with women more often affected in late teens/early 20s
• 1st degree relative with bipolar I has 10-20% risk of bipolar I, 1-5% risk of bipolar II, 10-20% risk of MDD
• Causes of bipolar disorders

  • Brain structure: Smaller basal ganglia and cerebellum
  • Genetic factors: 40% MZ twins, 5-10% DZ twins/siblings, 1-2.6% general population
  • Neurotransmitters: Overactivity of norepinephrine, low serotonin
• Permissive theory of mood disorders

  Low serotonin opens the door to a mood disorder, norepinephrine determines the type (low serotonin + low norepinephrine = depression, low serotonin + high norepinephrine = mania)
• Bipolar disorder treatments


  • Mood stabilizers (lithium, valproate, carbamazepine, olanzapine, lamotrigine)
  • Combination therapy (mood stabilizer + antipsychotic, add antidepressants)
  • Electroconvulsive therapy
• Bipolar disorder is difficult to treat, it is a chronic illness with multiple episodes over a lifetime, up to 15% of patients will die by suicide