Depressive and Bipolar disorders - Perspectives

Unipolar depressive disorders: Biological overview: Genes

Something genetically is passed down with unipolar depression

When they looked at twins they saw that in identical twins there is a 38% chance they both have it, fraternal a 20% chance

There are specific genes that are linked to depressive disorders and we are very confident about this in our research

Unipolar depressive disorders: Biological: Biochemical

Neurotransmitters: Serotonin (sleeping, eating, pain, mood, depression) and Norepinephrine (fight or flight response) are the neurotransmitters that are low with depressive episodes

Endocrine system: Chronic stress can disrupt the HPA axis, leading to excessive cortisol secretion, which has been linked to changes in brain structure and function, and is a common feature in many people with depression.

Unipolar depressive disorders: Biological: Circuits 

Serotonin pathway: Fewer serotonin neurotransmitters means communication in the brain s reduced/negatively impaired 

Neural activation of reward circuitry is underactive 

Neural activation of arousal, anxiety, and alarm are overactive 

Subgenual cingulate cortex 

Most important brain region in regulating emotion 

Correlates with depressed mood, and anhedonia 

Unipolar depression: Biological: Immune system

Associated with immune system alterations, including signs of immune suppression and inflammation

But while there is a correlation, we cannot believe this is a cause

Unipolar depression: CBT view

Cycle of

Self-defeating thoughts

Self-defeating emotions

Self-defeating behaviors

Self-defeating thoughts (unipolar depression CBT)

“There’s no point in doing anything” “things are too difficult” “I can sleep and forget about things”

Maladaptive attitudes (self-defeating thoughts of depression CBT)

These attitudes are developed in early life, can be triggered by life events which cause episodes

Cognitive triad (self-defeating thoughts of depression CBT)

Interpret experiences, themselves, and the future negatively

1. Negative views of self

2. Negative views of experiences

3. Negative views of future

Automatic negative thoughts (self-defeating thoughts of depression CBT)

Interpreting everything as being helpless, and therefore they cannot deal with it 

Errors in thinking (self-defeating thoughts of depression CBT)

Make arbitrary inferences

Cognitive distortions

• Minimize positive experiences

• Maximize negative experiences

Self-defeating behaviors (Depression CBT)

You stick to bed, avoid people, work and all potentially satisfying activities

These behaviors keep them stuck in a cycle, by doing this they are not able to get positive affirmations or rewards because there is no opportunity to

Self-defeating emotions (Depression CBT)

You feel tired, bored apathetic, self-hating, discouraged, guilty, helpless, worthless and overwhelmed

Sociocultural perspective on unipolar depressive disorders: Family-social

Unipolar depression is effected by social/family context

Bipolar disorders: Biological view: Biochemical (neurotransmitters)

There is an overactivation of Norepinephrine (fight or flight) and underactivation of Serotonin

Bipolar disorders: Biological view: Ions

Ions are directly involved in action potential

Typical way it works

• Sodium Ions: After neurotransmitters bind to receptors, sodium ions bind when channels open and make the neuron positive and allows it to fire

• Potassium ions: Channel opens after neuron fires and makes it negative again 

With mania: Neurons fire too easily (too much sodium), the neurotransmitters do not have time to bind, but the sodium channel still opens and the neuron still fires 

(depression would be underactivation)

Bipolar disorders: Biological view: Genes

There is genetic factor with bipolar disorders

Identical twins have a 40-70% chance of having it if the twin has it

Fraternal twins have a 5-10% chance of having it if a twin has it

Not as much of a factor as depression