l3 - Unipolar Disorders

Emotion

complex reaction pattern used by an individual to deal with a personally significant matter

• the type of emotion depends on the events specific sig

Difference between emotion and feelings

• emotion involves feelings but differs from feelings in having an overt or implicit engagement with the word

• Feelings are purely mental, whereas emotions are designed to engage with the world

Affect definitions

any experience of feeling or emotion, ranging from suffering to elation

Affect - can be split into

positive and negative affect

Feeling is a

self contained phenomenal experience: subjective, evaluative and independent of the sensations, thoughts or images evoking them, typically evaluated as pleasant or unpleasant

sex specific characteristics that have profound effects on the stress response

• females have higher levels of cortisol

• adrenal gland (produced cortisol) is larger in females

• female increased response to fear and stress

• Males secrete less cortisol in response to stress

gender specific characteristics that have profound effects on the stress response

• societal gender roles often result in women facing more stressors than men

• Men tend to reasons to more stressors involving achievement, whereas women find interpersonal conflict more stressful

• Men are less likely to be aware of the impact of stress on their health and less likely to receive treatment

both mood and emotion are ….

affective states

mood definition

a dispostion to respond emotionally in a particular way that may last for hours, days or even weeks.

Moods differ from emotions in…..

lacking an object

What are mood disorders?

mental health conditions in which the principle feature is prolonged, intense and persuasive affective disturbance

two main types of mood disorder in DSM5

1. unipolar - includes only depressive episodes

2. Bipolar - includes both manic or hypomanic, & depressive episodes

hypo

‘low ‘

criteria for major depressive disorder and related conditions

A: in a 2 week period, 5 or more symptoms present almost every day for most of the day (must include symptoms 1 +2)

1. depressed mood

2. diminished interest

3. weight loss/ gain

4. insomnia/hypersommnia

5. psychomotor agitation/retardation

6. Fatigue

7. Worthlessness/ excessive guilt

8. Concentration/ indecisiveness

9. Recurrent thoughts of death

   B: symptoms cause clinically significant distress/major functional impairment

   C: episode not caused by physiological effects of substance or medical condition

   D : disturbance not better explained by schizophrenia

   E complete absence of manic/hypomanic/ cyclothymic disorder

MDD diagnostic specifiers …. with

• anxious distress

• mixed features: mania/hypomania

• melancholic features

• atypical features

• psychotic festures

• catatonia

• permpartum onset

• seasonal patterns

How do other depressive disorder differ from MDD? - Persistent depressive disorder (PDD)

• Mdd symptoms for more than 2 years

• any break from symptoms in less than 2 months

How do other depressive disorder differ from MDD? - Premenstral dysphoric disorder (PDD)

• symptoms present 7 days before menstruation

• Remit in the week following

How do other depressive disorder differ from MDD? -disruptive mood dysregulation disorder (DMDD)

• Onset before 10 years, must be younger than 18 than older than 6 years at diagnosis

• more than 3 times a week temper outbursts

• mood between outburst persistently irritable

• present for more than 12 months

Cognitive changes in MDD

• moderate decrease in processing speed, attention, executive function, learning and memory.

Cognitive changes in MDD - cognitive bias

• distorted information processing and focus away from positive stimuli and towards negative (especially affective stimuli)

• Cog impairments can partially remain during …..

remission

• recurrent episodes increase risk of progressive function loss

Negative thinking and depression - beck - negative cogntive triad

negative thoughts about the self, environment and future.

• automatic and irretauonal thoughts are responsible for maintaining depression

  • Forms the basis of CBT

People with MDD that experience symptoms fro more than 2 years

10-20% - leads to diagnosis of PDD

• most people’s symptoms remit (gone for less than 2 months)- if reappear = relapse

depression recurrence - when symptoms remit for a longer duration

40—50% of people experience recurrence of MDD

• More likely as the number of previous episodes increases if other mental health conditions are present

Depression profile

• affects 6% of global pop

• young in adulthood

• identify as woman

• belong to specific ethnic group, although the specific groups vary between regions

• Identify as trans

odds ratio of depression in women vs men

• women 3x at ages 15ish

• women 2x as likely at 25

age is the strongest predictor of effect size for

symptom severity

Why do gender differences in depression exist?

• different patterns of risk factors

• gender discrimination

• differential exposure to childhood or adult adversities

• Biologically different stress responses

the stress response involved in depression - look at image

illustration of the multiple causes of depression

MDD and brain structure - look at image

MDD and brain function - functional differences - affective -salience circuit

amygdala is hyperactivated and hyper-connected with areas including dorsal ACC and insulation

MDD and brain function - functional differences - default mode network

hyperconnectivity correlates with higher levels of self-directed thoughts e.g. rumination

MDD and brain function - functional differences - front-parietal (cogntive control) circuit

hypo connectivity of this circuit may reflect difficulties in goal-directed tasks, under activity is observed at rest and for negative but not positive stimuli

The Brain as part of a bigger system in MDD - the brain communicates with……

the CNS, stress response (HPA axis), the ANS, and the immune system.

The Bain as part of a bigger system in MDD - how might this whole system cause depression when pre-existing risk factors and environmental triggers coincide?

1. psychological stressors = repeated HPA axis response

2. over time shows diminished feedback initiation capacity - chronically elevated cortisol and CRH

3. Chronically elevated levels of inflammatory mediators (cytokines)

4. Combination of stress response & immune activation affects the central nervous system: alters neural plasticity, connectivity and neurotransmission. May exacerbate tissue loss

5. May explain structural and functional brain differences seen in MDD

Causes of MDD - Chronic stress leads to chronic inflammation

• stress hormones and the behaviours linked to stress cause inflammation e.g. alcohol use, smoking, poor diet etc, which all predispose development of MDD

chronic stress leads to chronic inflammation = MDD, but bidirectional ambiguity

people are more likely to behave in these ways when stressed

Causes of MDD - prolonged stress alters the….

adaptive innate immune stress response and prolongs inflammation.

• inflammation itself perpetuates cognitive- affective- behavioural changes that themselves perpetuate stress

Early life experience programme immune and stress responses - MDD causes- intro

altered immune response develops in response to adverse early life events: a proinflammatory phenotype, shaped by the developing organisms exposure to social -environmental threat

Early life experience programme immune and stress responses - socio- environmental threats

• childhood adversity linked to subsequent exaggerated cognitive, emotional and biological stress response

• childhood obesity, diet and ,low physical activity (early systemic inflammation) predispose inflammatory responses across the life-course

• Compounded by socioeconomic disadvantage

social and environmental risk factors in MDD

• bereavement, divorce, chronic illnesses, dissemination, violence etc. these interact with genetic risk factors.

Social drift hypothesis

• People with mental illness, may expense detonating functioning

• Can lead to work and family problems, raises the likelihood of further socioeconomic disadvantage

• Compounded by systemic stigma, discrimination and marginalisation based on mental health status and socioeconomic disadvantage

Genetic risk factors for depression

heritability is at 35% and is polygenic

• MZZ co-twins of a twin with MDD are 2x as likely as DZ

• heritability is higher for more severe, early onset or recurrent depression

Greater proportion of individual differences in risk for MDD can be explained by

non shared environmental influences than genetic factors

Diathesis stress model for Mdd - suggest that stress can ….

precipitate the development of MDD in individuals who have pre-existing vulnerability to depression

Gene - environment interaction: the case of 5- HTTLPR- Kendler (2005)

individual studies suggested that MDD risk was partially determined by numbers of adverse environmental events on pre-existing risk in a dose dependent manner

Gene - environment interaction: the case of 5- HTTLPR- Culverhouse - Method

• meta-analysis of 31 datasets, Europeans genotyped for 5-HTTLPR and assessed for depression and stressful life events

• analysis’s targeted 2 types of stressors (narrow,broad) and two depression outcomes (current and lifetime)

Gene - environment interaction: the case of 5- HTTLPR- Culverhouse - results

• Findings did not support the interaction hypothesis: no sig inetrctaion between stress and 5HTTLPR genotyp

some environmental effects act via the epigenetic mechanisms to …

produce the MDD phenotype, phenotype includes differences on levels of molecules, brain and behaviour

Treatments for MDD - look at image

Antidepressant medication - SSRI’s

block the re-uptake Serotonin so it remains in the synaptic cleft for longer

Antidepressant medication - Tricyclic/ tetracyclic antidepressant

block re-uptake of serotonin and norepinephrine so they remain in the synaptic cleft for longer

Antidepressant medication - Monoamine oxidase inhibitors

an enzyme called monoamine oxidase is involved in removing norepinephrine serotonin and dopamine from the brain: Maoi’s stop this happening

Effectiveness of medication - cipriaini

meta-synthesis of antidepressant effectiveness , all 21 varieties exa one performed better than placebo

Nt and MDD - initially monoamine hypothesis focused on hypothetical deficiencies of serotonin, noradrenaline and dopeamine - however it is more complex:

• rapid change to 5-HT concentration in the brain is not consistent with the delayed onset of symptom relief in SSRI’s

• Lowering 5HT concentration in the brain doesn’t induce depression in people without MDD

• Long-term antidepressant treatment actually down regulates total 5HT concentration in the brain

• No evidence of problems with monoamine receptor dysfunction in the brains of people with MDD

Nt and MDD - initially monoamine hypothesis focused on hypothetical deficiencies of serotonin, noradrenaline and dopeamine - however it is more complex: - CASTING DOUBT ON

A) neurotransmitter concentration B) receptor insensitivity theories as incomplete explanations

Serotonin- targeting drugs: other possible mechanisms - Neuronal growth

the delay in symptom relief when antidepressants drugs are started may suggest that new neurones need to grow (neurogenesis) in ket areas of the brain (e..g hippocampus) in response to antidepressant, for some people

Serotonin- targeting drugs: other possible mechanisms - chronic stress

• chronic stress substantially alters neuronal circuits in the brain, including disruption of intracellular signalling and the number and function of synapses

• Antidepressants may help reverse some of these changes by increasing neural plasticity - occurs via brain derived neurotrophic factor

treatments for MDD - CB

• thoughts, behaviours and emotions can be reciprocally deterministic

• AlL these affect how our brain functions, stress levels and how behaviours either increase or decrease inflammation

CBT helps us recognise the relationship between….

thoughts, behaviours and emotions in our lives, making changes to thoughts and behaviours to enhance emotional experiences/ symptoms

CBT for MDD

• helps patients indentify negative, distorted thinking patterns that contribute to depression

• Provides skills to test and challenge these negative thoughts

• Behavioural activation helps patients increase positive activities that provide a sense of pleasure

• Processes used to avoid activities are tested and reduced

How many sessions on average for CBT

• 16-20 sessions over 3-4 months

CBT For MDD - Collaborative empiricisms

patients and the therapist become co-investgators both in ascertaining the goals for treatment and investigating the patients thoughts

Effectiveness of CBT

• More effective than doing nothing

• Effect size (hedges g) moderate to large, also more effective than usual care or pill placebo

• CBT marginally more effective than mediation alone for MDD

Interpersonal therapy to treat MDD

• Psychological problems understood as responses to current difficultuies in day to day interactions with others

• focus on attachment, grief, role transitions, interpersonal disputes and deficits

How many sessions for intrapersonal therapy

• Time limited (12-16 sessions)

IPT aims to improve ….

• interpersonal functioning, well being and through helping individuals effectively communicate, resolve interpersonal crises and help patients effectively use social support

effectiveness of IPT reduced depressive symptoms in comparison to placebo, and in combination with….

antidepressant (Cuijpers et al 2011)

Other psychosocial approaches for MDD treatment recomended by NICE - physical activity program

(Mild to moderate symptoms)- increasing social engagement and reducing somatic complaints

Other psychosocial approaches for MDD treatment recomended by NICE - couples therapy

useful when the person has a regular partner and where relationship may contribute to development/maintenance of depressive symptoms

Other psychosocial approaches for MDD treatment recomended by NICE - Counselling and psychodynamic psychotherapy

• c - (6-10 sessions over 8-12 weeks)

• P - (16-20 sessions over 4 -6 months)

Which is more cost effective ? Psychological therapies or medication?

• health economics modelling study based on data from the USA

• cBT and second generation antidepressants appear equally cost effective across the course of 5 years