Mood Disorders

Lecture 4

Major Depressive Disorder (MDD)

Episodes of severe low mood/anhedonia which impairs functioning which last 4-6 months and often recur without treatment

Very heterogeneous (experience is very different for each person)

Duration of MDD episodes

less than one month = 25%

less than 3 months = 50%

one year = 15-39%

2 years = 22%

Relapse rates of MDD

after 2 months: 20%

after 6 months: 30%

within first year: 40%

by second year: 50%

Physical/somatic symptoms of MDD

• tiredness

• lack of energy

• agitation

• slowness

• sleep changes

• appetite changes

• loss of libido

• lack of motivation

• physical pain

Emotion symptoms of MDD

• sadness

• loss

• hopelessness

• worthlessness

• tearfulness

• anger

• irritability

Cognitive symptoms of MDD

• self-criticism

• indecisiveness

• pessimism

• suicidal thoughts

• memory disturbance

• rumination

• negative bias in self perception

• inflated, grandiose thinking

• psychosis

Behavioural symptoms of MDD

• psychomotor slowing or agitation

• dependency

• crying

• lack of goal-directed activities

• “zombie living”

• lack of self-care

• self-harm

• self-medication

Prevalence of MDD

3.8% (~280 million)

Causal/Maintenance factors of MDD

• genetics/heritability

• Freud: importance of loss

• Beck’s Cognitive Model

• adversity in early years

• personality/individual differences

• stressful life events (environmental)

• lack of positive reinforcement/more negative reinforcement

What affects rates of MDD

• willingness to report symptoms (women more likely so more common in women than men)

• hormonal changes (women)

• COVID-19

• financial difficulties

• relationship status (single associated more with MDD)

Beck’s Cognitive Model of MDD

Early experiences + activating event →

Core beliefs formed/assumptions →

Negative thoughts →

Physical/emotional/behavioural symptoms →

Reinforce core beliefs/assumptions

Bipolar I Disorder

Experience of at least one episode of mania thought life (state of elation or irritability)

Don’t need to experience depression but most do

Bipolar II Disorder

At least one hypomanic (less severe mania) episode and one depressive episode

Hypomania doesn’t cause significant impairment

Manic-Depressive Spectrum

Prevalence of Bipolar Disorders

0.6% for BP I

0.4-2% for BP II

Much less common than MDD

Onset before 25

Most experience 4+ episodes in their life

Causal/maintenance factors of BPD

Similar triggers to depression:

• one of the most heritable disorders

• elevated cortisol levels

• connection to neurotransmitters (serotonin, norepinephrine, dopamine)

• early life adversity

• negative life events

• neuroticism

• negative cognitive styles

• family criticism

• lack of social support

• sleep disturbance

• reward sensitivity

Suicide/Suicide Ideation

Leading cause of death for 10-24 year-olds

Men are 1.7 times more likely to die by suicide than women

750,000 people die each year by suicide

Prevalence of suicidal ideation

9%

Risk factors of suicidal ideation/suicide

• having a mental health disorder

• heritability

• abnormalities of serotonin system

• social factors (e.g. world events, physical/sexual assault, lack of social belonging/isolation, divorce/widowhood)

Treatment for Mood Disorders

Psychotherapy:

• CBT

• Behavioural activation therapy (increase participation to decrease negative reinforcement)

• Psychoeducation

Medication:

• antidepressants (e.g. SSRIs, tricyclics)

• mood stabilisers (e.g. lithium)

• antipsychotic drugs

Cultural influences of mood disorders

• cultural focus on mental vs. physical symptoms

• willingness to report symptoms

• factors such as seasons, national income equality, family cohesion, stigma