What's the angle?
Tacchi is a psychiatrist and Scott is a psychologist, both hailing from Newcastle. They begin the book with a history of melancholia, from Hippocrates to Avicenna to Freud, and even provide a quick glance into traditional Islamic, Indian, and Chinese views of depression. Then they present the leading theories on the causes, risk factors, and solutions to depression. In the final chapters they discuss controversies in the study of depression and estimates of its social and economic costs.
What causes depression?
historic theories
- an imbalance of the humors, or too much black bile
- misperception or misunderstanding of life events
- demons or possession
- punishment from God or spirits
- imbalance or disturbance of the doshas (similar to humors, in Ayurveda medicine) caused by difficulties of mind, difficult life experiences, or difficulties of the environment
- internal blockages disrupting the flow of Qi/Chi
- "mechanical theories" in 18th and 19th centuries hypothesized a disturbed flow of internal fluids (blood, lymph, nerve fluid)
- Freud - melancholia is like bereavement, but mostly unconscious grief over the loss of an "ideal object"
contemporary theories
- monoamine hypothesis: monoamines - norepinephrine, dopamine, and serotonin - are a subset of neurotransmitters. In the 50's it was discovered, incidentally, that a drug which tended to decrease monoamine levels sometimes had depression-like side-effects, and a drug which tended to increase monoamine levels sometimes had anti-depressant side effects. Further study confirmed that there is a significant correlation between low levels of serotonin and depression. Is it cause, or effect, or bidirectional, or none of the above?
The hypothesis is that one of the major drivers of depression is 1) low serotonin (because not enough is produced, or it is broken down too fast, or re-uptaken too quickly) or 2) low receptor sensitivity to serotonin.
However, not all drugs that effect monoamines also effect mood in the expected direction, and anti-depressant medications which target serotonin have a hit-or-miss record (about 20% effective, when the placebo effect is accounted; they said that's not great, but not terrible when it comes to drug effectiveness). And little is known about how the 30-some-odd neurotransmitters really interact with each other, or how their relative levels are related to mood disorders.
- neuro-endocrine hypothesis: disturbances in several hormones have been linked to depression, and people with endocrine disorders are often at higher risk for depression. Most depression related research has been done on the hypothalamic-pituitary-adrenal (HPA) axis, which is the main stress regulator. The hypothesis is that the system kind-of gets stuck in a chronic stress mode, even when there aren't recognizable stressors. Childhood trauma can have a similar effect. Cortisol levels remain high, which can undermine mental and physical health.
However, not all people with HPA abnormalities have symptoms of depression, and not all people with depression are shown to have HPA abnormalities.
- Aaron Beck's hypothesis: this is the basis of cognitive behavioral therapy. Beck maps a path backwards from feelings to thoughts, from thoughts to beliefs, and from beliefs to our experience, especially early experience. Basically, he hypothesizes that if we're depressed, there's a good chance it's because we're thinking (cognition) lots of negative things, almost automatically, about ourselves. And if we're thinking lots of negative things, it's probably because we have developed certain beliefs (cognitive schemata) that lead to those thoughts. And we have probably generated these beliefs through (mis)interpretation of negative experiences, often early in life.
-Brown and Harris' social hypothesis: Hari (Lost Connections) also dives into the research of George Brown and Tyrell Harris, which they began in the 70's. They didn't make a specific hypothesis, but they demonstrated correlations between social stressors, which they called risk factors, and depression. And these social stressors display a dose-effect: the more stressors, the more likelihood of depression. Certain stressors, like experiences of humiliation or entrapment, were particularly high risk factors. So basically, their hypothesis is that social stress is a major driver of depression.
-the biopsychosocial hypothesis: everything causes depression! No, Tacchi and Scott write that most researchers and medical professionals believe that there are or can be multiple overlapping "causes" of depression. One way to express that is with a stress-vulnerability model, where stressors can be bio, psycho, or social, and the vulnerabilities can as well. Abnormally low serotonin might be a vulnerability, and losing your job might be a stressor. On the other hand, being unemployed might be a vulnerability, and then having a disruption with your monoamines might be a stressor. I think.
What are the treatments for depression?
historic treatments
- purging
- bloodletting
- exercise
- herbal teas
- bathing, rest, sunshine
- Avicenna recommended persuasive talking
- the first known care facility for mental illness was established in Bagdad, 705ce
- exorcism
- witch-hunts
- sedatives
- brain surgery
- spinning rapidly in a chair! (Benjamin Rush believed it would help with inflammation)
contemporary treatments
- Electroconvulsive treatment (ECT); they say this has developed a lot since One Flew Over the Cuckoo's Nest. It's primarily used in cases when other treatments aren't helping, or when there is a medical emergency (like the patient won't or can't eat). When it does help, it often helps immediately.
- Transcranial magnetic stimulation; using magnetic fields to stimulate brain nerve cells.
- Brain surgery is still practiced for desperate cases of depression. Stereotactic surgery is the newest practice, which places small electrodes in certain places associated with emotional control.
- Vagal nerve stimulation; originally designed for treating epilepsy, it has also shown some effectiveness in treating depression.
- Drug therapies; the most common are SSRI's and lithium.
- Psychotherapies; Interpersonal therapy and Cognitive Behavioral Therapy are two of the most recommended therapies.
What other research is being done about depression?
The authors briefly introduce some promising research on the relationship between circadian rhythms and mood disorders, as well as the immune system (particularly inflammatory markers) and mood disorders. They also mention further exploration of neuroplasticity, and the potential ways neuroscience can help study the effectiveness of psychotherapies.
In their final chapter I was particularly impressed with a couple studies estimating the work costs of depression. In the U.K. one team estimated that a depressed person loses an average of 22 work days per year, and another study in the U.S. estimates an average of 5-8 hours per week of work lost.
I've often wondered how I could quantify or describe how much more productive I am when I'm feeling well as opposed to depressed. Eight hours, or a day per week, is probably accurate. Because I spend a lot of time depressed yet functional, and because my work isn't particularly interested, when I'm feeling up at work, it's almost a magical experience. I'm more motivated, alert, and lighter on my feet. It's so much easier to start or change tasks, to change direction mentally and physically. I can rebound from failure more quickly, mistakes don't shackle me, while success is more pleasing.
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notes
- Hippocrates - melancholia characterized by despondency, aversion to food, sleeplessness, irritability, and restlessness (too much black bile)
- Galen - certain personality types may lend themselves to certain problems
- Avicenna - both body and soul affected by melancholia, persuasive talking
- Benjamin Rush's spinning chair
- bipolar vs unipolar
- Freud
- topography of mind: conscious, preconscious (accessible), unconscious
- personality: id, ego, superego
- sexual development: oral, anal, phallic
- Freud - Mourning and Melancholia, melancholia like grief, except the loss is of an "ideal object" and the loss is partially unconscious
- one-year rate of depression (american study) highest among 18-25yr olds
- 2x higher in women
- symptoms of "post-natal depression" can begin before birth
- about 1 million suicides each year, globally
- monoamine hypothesis; monoamines (a subgroup of neurotransmitters): norepinephrine, dopamine, serotonin
- neuro-endocrine hypothesis: trouble with the regulation of stress responses within hypothalamic-pituitary-adrenal axis; chronic stress or adversity different from usual reaction; cortisol levels remain high, etc
- Aaron Beck (CBT): event-thought-feeling-behavior; cognitive structures/schemata (thoughts and beliefs) and cognitive mechanisms (reasoning)
- events/feelings of humiliation and entrapment esp. associated with depression
- stress vulnerability model (biopsychosocial)
- identical twins more likely 46% to both have depression than fraternal twins 20%
- Baghdad 705AD, first record of asylum, historically Islam very compassionate toward mental illness
- evolution of treatments: sedatives, electroconvulsive treatment (ECT), transcranial magnetic stimulation (TMS), antidepressants, lithium (7-up started as a lithium tonic!)
- therapy - not as much funding for studying, also harder to set-up studies; CBT and IPT (interpersonal therapy)
- chronic disease management models - like diabetes and hypertension
- only group shown to consistently benefit from antidepressants - severely depressed
- monoamine and stress hormone systems connected - also bidirectional influence to genetic, psychological, and environmental factors
- possible link between circadian rhythms and mood disorders
- link also to immune system (higher levels of inflammatory markers, higher risk of depression)
- absenteeism and presenteeism
- estimate 5-8 hours of work lost per week
- mental capital: general abilities, how flexible and efficient at learning; emotional intelligence, such as social skills and resilience under stress
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