Mood Disorders Flashcards
Major depressive disorder symptoms
Great sadness Apprehensive feelings of worthlessness Guilt Withdrawal from others Loss of sleep/appetite Decreased sexual desire Loss of interest & pleasure in usual activities
What MDD looks like to others
Paying attention to other people difficult
Conversation may be tiresome
May speak slowly, take long pauses, use few words & uncomfortable periods of silence
May want solitude
May become agitated, pace uneasily etc
May neglect their personal hygiene & appearance
Other depressive disorders
Dysthymia disorder; more persistent but less severe form of MDD (2.5-5% prevalence) SAD; >melatonin in winter (1-3%) Chronic fatigue; unknown cause, mostly women Post-natal blues: 50-66% Post-natal depression; 10-15% Bearevment related depression Premenstrual dysphoric disorder Disruptive mood dysregulation disorder Substance/medication induced DD DD due to another medical condition
Possible triggers of MDD
Psychosocial stressors
Illness
Medications
Other; family history of depression, seasonal changes, menopause
Prevelance of MDD
3rd most common reason for seeing GP 17% have depressive disorder 6% have MDD More common in women Recognised in 50% of cases Many more have depressive symptoms (mild depression)
Onset & duration of MDD
Average age of onset is 30
Incidence is increasing
30-50% recover with usual care within 6 months
Typical duration of first episode is 2-9 months of untreated
Poorer prognosis the earlier age of onset; less responsive to treatment, increased chronicity, stronger heritability
4x higher rate of suicide
Co-morbidity
74% with one other disorder
58% with anxiety disorder
38.6% substance use disorder
Future predictions
WHO
by 2020, leasing cause of disability worldwide
Reasons MDD is believed to be over-diagnosed
Catch all diagnosis
Medicalising sadness
Diagnostic criteria very low
No coherent pattern of neurobiological changes or pattern of treatment response
Evidence based for antidepressants is weak & contradictory
Driven by vested interests e.g. drug companies
Reasons MDD is believed to not be over-diagnosed
Increased treatment has outweighed harm
Increased diagnosis rate led to reduced stigma & wider public understanding
Led to neurobiological, genetic & psychosocial risk factor studies
May lead to more preventative treatments in earlier developmental periods
Self-harm
Expression of personal distress
Usually made in private by individual who hurts themselves
30% rise among 10-14 yr olds
1/5 teenager prevalence in UK
Suicide
Around 15% of depressed people kill themselves
Global mortality is 16/100,000
11.7% per 100,00 men
3.3% per 100,000 women
More common in young people; 66% of cases <35 yrs
Women 3x more likely to attempt, men 4x more likely to succeed
Predominantly found in Caucasians
3rd highest cause of death in teenagers
Risk factors; impulsive, irritable, aggressive
56% thought of death, 37% wished to die, 69% had suicidal ideas
Risk & prognostic factors
Temperamental; neuroticism & link to stressful life events
Environmental; adverse childhood experiences, stressful life events
Genetic & physiological; familial risk
Course modifiers; all major non-mood disorders
Aetiology
Biogenetic factors; genetic, neurochemical, neuropathology, neuroendocrine, inflammatory markers
Psychological factors; perception of control, emotion processing, emotion regulation & reward seeking
Sociocultural factors; ethnicity, SES, gender
Genetic factors
2-3x higher rate in those with relatives with mood disorder
MZ; 46% concordance
DZ; 20% concordance
30% variance in depressive symptoms accounted for in inherited factors
10-15% prevelance if close family member
Lower % for MDD in comparison with other major psychiatric disorder
Sex differences
Bierut (1999) 2,600 twins Increased rate of depression in women Vulnerability genes determine risk Environmental factors have larger role determining onset
Neurochemical imbalance
Low serotonin & norepinephrine
Serotonin regulates emotional reactions
Decreases lead to increased impulsivity & mood swings
50’s; drugs developed which reduced symptoms
More recent antidepressants act as a SSRI
Neuropathology
Prefrontal cortex, anterior cingulate cortex, hippocampus & amygdala
Role of areas; reduced anticipation in incentives, reduced will to change, reduces ability to contextualise affective reactions & increased emotional salience given to stimuli
Neuroendocrine factors; the stress hypothesis
Stress hypothesis
Hippocampus involves in adrenocorticotropic hormone secretion, abnormalities linked to abnormal cortisol levels
Increases cortisol levels can cause enlarged adrenal glands & reduces serotonin levels
Life stressors increase levels of cortisol
Blunted cortisol response
Variation in 5-HTT gene which moderates influence of stressful events on depression
Serotonin transporter gene
Serotonin transporters remove serotonin from synaptic cleft
Increased depression & suicidality found in short allele expressive
Relation between number of stressful life events, 5-HTT allele type & depression
Negative cognitive styles; Beck (1967) Cognitive Distortion Model
Depression primarily a disorder of thinking rather than mood
Negative triad; self, works, future
Negative scheme/belief; triggered by -ve life events
Cognitive biases; over-generalising (one outcome applies to all cases even slightly similar), excessive responsibility (I am responsible for bad things), assuming temporal causality (it will happen again), self-references (I am centre of everyone’s attention), catastrophising (thinking worst), dichotomous thinking (everything is black or white)
Learned helplessness; Seligman (1975)
Related to degree of control we believe we have over our lives
Depression attributions style;
Internal= attribute -ve event to personal failings
Stable= attribution remains after -ve event
Global= attributions extend to variety of issues
Cause or effect?; Nolen-Hoeskema (1992)
5 yr study
Children
Negative attributions style does not predict later symptoms of depression in young children
Stressful life events largest predictor of depression
Sociocultural-cultural factors
Prevelance increased in poor, ethnic minorities & those with poor social or marital support
Economic deprivation leads to negative events, also have less resources to cope
Stress of prejudice
Women have more responsibilities & lower quality of life
Why is depression more prevalent in women?
More likely to ruminate about symptoms, men more likely to distract themselves or express as anger
Experience more life stressors
Being married & having children increases risk of major depression in women but not in men
Components of depression
Motivational deficits
Behavioural symptoms
Cognitive features
