Posts tagged: depressive

Happiness and Desire

Business Logo for Psychological and Neuropsychological IssuesFor over fifty years, scientists have been able to influence rat behavior through the use of brain implants.  This does not mean that scientists are able to create a mammalian robot.  The behaviors elicited by rodent brain stimulation are primarily limited to eating and sex.  Scientists have interpreted the increase in these behaviors as an artificial increase in the pleasure experienced by eating or having sex.  Once the rat was given control over the charge sent to their brain, they would continue to self-stimulate until exhausted.  This observation was regarded as proof that the electrical stimulation induced a feeling of euphoria.  Food and females were ignored in favor of electrical self-stimulation.

Much more recent research (Berridge & Kringelbach, 2010) suggests that earlier scientists had leaped too far in their conclusions.  These scientists have discovered that wanting and liking are neurologically distinct.  At first blush, this sounds rather obvious and simplistic.  At the second blush, it sounds a bit off kilter.  Why would someone want something they do not like?  At the third blush, it begins to gather more common sense.  Many people perform work they do not enjoy in order to receive money.  People want money, and will perform dreary behaviors in order to gain this end.  More to the point, drug addicts continue to strongly desire a drug long after its pleasurable effects have evaporated.  As the need for the drug increases, the pleasure attained by the drug decreases.

In regards to recreational drug dependence, dopamine is most often implicated as the neurotransmitter of addiction.  Cocaine and other amphetamines significantly increase the amount of dopamine available at brain synapses.  Berridge and Kringelbach found that the dopamine is related to desire-not pleasure.  Once a rat brain is depleted of dopamine, they will tend to lose interest in their environment.  This ignores the fact that if food is presented to the dopamine depleted rat, it will eat and appear to enjoy the food as much as a normal rodent.  The difference is that the rat will not seek out the food in a spontaneous fashion.  Conversely, rats with elevated dopamine will seek out and consume larger quantities of food, but once they are sated, the rodent will display facial signs of displeasure as they continue to eat more than they require.

This new model becomes even more complicated when the notion of pleasure is entertained.  As mentioned, it does not appear that the dopamenergic neural circuits of desire have much to do with pleasure.  Many areas in the brain stem and cortex need to be simultaneously activated to produce pleasure.  This is in contrast to the relatively circumscribed neurology of desire.  The reward areas of the brain are strongly connected to other areas that evaluate the experience in real time.  A small area at the bottom-front of the brain appears to regulate when the animal is sated-when enough is enough.  A little chocolate syrup on ice cream elicits delightful anticipation, but the mere thought of drinking an entire can of the syrup is sickening.  This is the prefrontal cortex acting as the internalized mother.  Many distinct areas of the brain feed into this area, giving near instant updates of bodily status and comparisons to prior behavior.

The dissociation between desire and pleasure may have implications for the treatment of depression.  Anhedonia is defined as the loss of pleasure experienced by depressed people.  For example, someone who is an inveterate football fan will derive little pleasure from watching the big game.   Perhaps electrical stimulation of cortical pleasure centers may help depressives regain some pleasure from life.  Similarly, gambling and drug addiction are repetitive behaviors that bring less pleasure the longer they are experienced.  Highly targeted electrical stimulation may return the balance between wanting and liking.  The desire to gamble or use drugs would decline in relation to the loss of pleasure experienced.

Fortunately or unfortunately, it is unlikely that mental disorders will be treated by implanted electrodes anytime soon.  The reseach by Berridge and Kringelbach highlights the errors that accrue when complicated aspects of behavior are reduced to one or two discrete areas of the brain.  Increasingly, research points to specialized areas of the brain that act in concert with other areas to produce a given behavior.  Because humans need to simplify problems, it does not follow that the study of brain function will conform to this need.

Early research discovered pleasure where there was only desire.  Current research suggests that one aspect of happiness is the congruence of pleasure and desire.


Business Logo for Psychological and Neuropsychological Issues Americans prize their independence.  Hollywood earns billions portraying characters that express their independence in an aggressive fashion.  Many Americans loath dependence and equate it with weakness.  Is dependence really equatable with weakness?

The author’s experience with nursing home and hospital patients over the last twenty years may shed some light.  The severely medically ill typically dread becoming a burden on their loved ones.  It is rare to find older adults who readily agree to live with their children.  Rarely does the avoidance stem from ill feelings, as from the aforementioned dread of becoming a burden.  The ailing older American is typically more resistive of living with their children than the children themselves.

Other cultures have less difficulty with dependence.  These patients typically experience less adjustment problems with illness and nursing home placement.  Forced dependence from medical illness is viewed as an unavoidable part of life, rather than stemming from a personal inadequacy.  Just as they may have taken care of ailing friends and relations, there is an expectation that it is a societal necessity to receive care in turn.  In such cultures, the resistance to unavoidable dependence would be taken as askew, and possibly indicative of mental illness.

These notions regarding dependence are focused on physical rather than mental illness.  Quite often long-term mental illness has a significant impact on parenting style and resources.  This impact may be resented by the children as they age; especially as they compare notes with peers whose parents did not suffer with mental illness.  Children of recurrent depressive and bipolar patients are often the least motivated to care for an incapacitated parent.  The very real physical responsibilities of providing care is even more difficult when the parent is uncooperative and apparently unappreciative.  It is nearly impossible for children to fathom the role of mental illness in parenting, as it requires a prospective obtained outside the confines of the family unit.

In regards to mental illness, there was a disorder termed Dependent Personality Disorder.  This so-called disorder is no longer a part of the diagnostic nomenclature, but its very existence is significant.  Dependent Personality Disorder was confined to the American diagnostic manual of mental disorders, and has never been a part of the international classification of mental illness.  Too much dependence was viewed as a mental illness, and psychologists and psychiatrists were given the task of drawing the line.  Dependence was not only considered a weakness, but possibly a disease that required treatment.

Anthropologists and evolutionary psychologists now consider the the role of grandparents as an advantage unique to our species.  Grandparents living within the family unit were able to confer knowledge and skills to the children that the parents were too busy to provide.  This advantage may be the reason other forms of humanoids became extinct.  Prior to World War II, it was the norm for couples to live with their parents for many years.  Married couples initially depended upon their parents, and in turn, the parents came to depend upon their children.  It may be merely an artifact of simple economics, but the children and grandparents may have benefited in ways that were not reducible to mere income potential.

Dependence is a problem if either party perceives it as a problem.  Dependence is highly influenced by cultural norms.  Dependence stemming from mental illness is often less well received than physical incapacity.  Dependence may be an evolutionary adaptation that secured our species spot at the top of the food chain.  We depend upon others for their knowledge and experience, as well as physical support.  Others depend upon us for the very same reasons.  Perhaps dependence is often perceived as a weakness by those who are afraid of the responsibility.  The responsibility is to not hate those on whom we depend.  It’s very American.

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