Wednesday, January 4, 2012

Biological & Sociological Theories of Schizophrenia

This is a mental disorder characterized by a breakdown of thought processes and by poor emotional responsiveness.It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social or occupational dysfunction. 

A person diagnosed with schizophrenia may experience hallucinations (most reported are hearing voices), delusions (often bizarre or persecutory in nature), and disorganized thinking and speech. The latter may range from loss of train of thought, to sentences only loosely connected in meaning, to incoherence known as word salad in severe cases.

Social withdrawal, sloppiness of dress and hygiene, and loss of motivation and judgment are all common in schizophrenia.Genetics, early environment, neurobiology, and psychological and social processes appear to be important contributory factors; some recreational and prescription drugs appear to cause or worsen symptoms.Current research is focused on the role of neurobiology, although no single isolated organic cause has been found.

There are many approches to describe Schizophrenia.Although fact is still unkown but researches were been made to describe it.

There are two main approches to describe Schizophrenia:

1.      Bio-determinal approach also known as Biological theories

2.      Social Based Approach also known as Sociological theories

Biological Theories of Schizophrenia
In these kind of theories the determinants of mental illness are internal (physical body).There are two major theories:

Neurodevelopmental Theorey of Schezophernia
The neurodevelopmental theory of schizophrenia has been of great importance focusing most etiologic research over the past two decades.
According to this theory there is deviance in early brain development whose full adverse consequences emerge only in adolescence or early adulthood (2-4).
In its simplest form this theory posits that schizophrenia is the behavioral outcome of an aberration in neurodevelopmental processes that begins long before the onset of clinical symptoms and is caused by a combination of environmental and genetic factors

Early Onset Schizophrenia (EOS)

Early Onset Schizophrenia (EOS) is a rare and severe formof schizophrenia in which onset occurs during childhood (COS) or adolescence (AdOS) up to the age of 17 years.Only around 4% of schizophrenia patients will experience an early onset. Longitudinal studies have shown diagnostic stability to be high in EOS at around 80-90% (6, 7).

Studies investigating prognosis in this group used a range of variables to assess outcome; typical indicators include presence of symptoms, length of remission, number and duration of hospitalizations, educational and occupational impairment and social disability. Evidence from studies that followed up EOS patients over 40 years confirm that outcome on such measures is consistently worse for EOS compared to adult-onset schizophrenia (AOS) (7-9), with some evidence that COS, with an onset before age 12, is associated with the worst clinical and psychosocial outcomes (10).

EOS is clinically and neurobiologically continuous with AOS, but is associated with greater neurodevelopmental deviance early in life (11, 12). EOS could therefore provide an opportunity to learn more about the neurodevelopmental aspects of schizophrenia.

This paper presents a selective overview of research on the neurodevelopmental aspects of EOS: namely, premorbid development, cognitive function, genetics and neurobiology. Particular attention is given to research on developmental delay and impairment in the areas of motor, social and language function.

The Dopamine Theorey of Schezophernia

The dopamine hypothesis of schizophrenia or the dopamine hypothesis of psychosis is a model attributing symptoms of schizophrenia (like psychoses) to a disturbed and hyperactive dopaminergic signal transduction. The model draws evidence from the observation that a large number of antipsychotics have dopamine-receptor antagonistic effects.

Evidence for the dopamine hypothesis

Amphetamine, cocaine and similar drugs increase levels of dopamine in the brain and can cause symptoms which resemble those present in psychosis, particularly after large doses or prolonged use. This is often referred to as "amphetamine psychosis" or "cocaine psychosis," but may produce experiences virtually indistinguishable from the positive symptoms associated with schizophrenia. Similarly, those treated with dopamine enhancing levodopa for Parkinson's disease can experience psychotic side effects mimicking the symptoms of schizophrenia. Up to 75% of patients with schizophrenia have increased signs and symptoms of their psychosis upon challenge with moderate doses of methylphenidate or amphetamine or other dopamine-like compounds, all given at doses at which control normal volunteers do not have any psychologically disturbing effects.

Some functional neuroimaging studies have also shown that, after taking amphetamine, patients diagnosed with schizophrenia show greater levels of dopamine release (particularly in the striatum) than non-psychotic individuals. However, the acute effects of dopamine stimulants include euphoria, alertness and over-confidence.

Evidence against the dopamine hypothesis

Further experiments, conducted as new methods were developed (particularly the ability to use PET scanning to examine drug action in the brain of living patients) challenged the view that the amount of dopamine blocking was correlated with clinical benefit. These studies showed that some patients had over 90% of their D2 receptors blocked by antipsychotic drugs, but showed little reduction in their psychoses. This primarily occurs in patients who have had the psychosis for ten to thirty years.
At least 90-95% of first-episode patients, however, respond to antipsychotics at low doses and do so with D2 occupancy of 60-70%. The antipsychotic aripiprazole occupies over 90% of D2 receptors, but this drug is both an agonist and an antagonist at D2 receptors.
Furthermore, although dopamine-inhibiting medications modify dopamine levels within minutes, the associated improvement in patient symptoms is usually not visible for at least several days, suggesting that dopamine may be indirectly responsible for the illness.
Sociological Theories of Schizophrenia
In these theories determinants of mental illness are external (in environment or person’s social situation).These theories don’t explain fully all causes of mental illness.However, demonstrate that mental illness is not randomly distributed among the population but tends to occur more in disadvantaged groups.Three main theories are mentioned here:

Stress Theory
Stress has both physiological and psychological components. We respond to external events or even imagined events with a generalized set of responses called General Adaptation Syndrome or the stress response, but our responses are to some degree tailored to the nature of the event.
Selye studied animals exposed to negative stimuli and found 3 stages of response:

Flight or fight
The Alarm Phase- The body mobilizes the sympathetic nervous system to meet the      immediate threat, the release of adrenal hormones, epineprine and norepinephrine, occurs with any intense emotion and produces a boost in energy and tense muscles reduced sensitivity to pain, the shutting down of digestion, along with a rise in blood pressure.
Decades earlier a psychologist Walter Cannon (1929) called this reaction "fight or flight", which is still used today. 

The Resistance Phase- Your body attempts to resist or cope with a persistent stressor that cannot be avoided.In this phase the physiological responses of the alarm phase continue. However, these very responses make the body more vulnerable to other stressors.
For Example, when your body has mobilized to fight off the flue, you may find you are more easily annoyed by minor frustrations. Eventually the body will adapt to the stressor and return to normal. 

The Exhaustion Phase- Persistent stress lowers the body of energy, and increases vulnerability to physical problems and eventually illness.
The same reactions that allow the body to respind effectively in the alarm and resistance phases are unhealthy as long-range responses. Tense muscles can cause side effects such as headaches and neck pain along with increased blood pressure ad digestive disorders.
Hans Selye believed there was no such thing as a stress free live. Some stress can be  positive and productive, even if it requires the body to produce short-term energy. Selye also believes that some negative stress is unavoidable. 

Treatment/prevention implications of stress theory
·        Changing environment Eliminate/reduce stressors
·        Give a stronger sense of control
·        Increase social support

Structural Strain Theory
Society’s organization puts some groups at an economic disadvantage and Economic disadvantage is a strain that leads to higher rates of psychological breakdown
According to Webster’s dictionary strain (in the form of a verb) means to be subjected to tension or stress.
Strain may be either:
  • Structural: This refers to the processes at the societal level which filter down and affect how the individual perceives his or her needs, i.e. if particular social structures are inherently inadequate or there is inadequate regulation, this may change the individual's perceptions as to means and opportunities.
  • Individual: This refers to the frictions and pains experienced by an individual as he or she looks for ways to satisfy his or her needs, i.e. if the goals of a society become significant to an individual, actually achieving them may become more important than the means adopted.
In criminology, the strain theory states that social structures  within society may pressure citizens to commit crime

Treatment/prevention implications of Structural Strain Theory
·        To prevent psychological breakdown, need large scale interventions—e.g., guaranteed income.
·        However, Seattle and Denver Income Maintenance Experiments showed minimal benefit from income guarantee in preventing symptoms of psychological distress       
Labeling Theory
Labeling theory had its origins in Suicide, a book by French sociologist Émile Durkheim. He found that crime is not so much a violation of a penal code as it is an act that outrages society. He was the first to suggest that deviant labeling satisfies that function and satisfies society's need to control the behavior.
Howard Becker who first began describing the process of how a person adopts a deviant role in a study of dance musicians.He later studied the identity formation of marijuana smokers. This study was the basis of his Outsiders published in 1963. This work became the manifesto of the labeling theory movement among sociologists. In his opening, Becker writes:
      “social groups create deviance by making rules whose infraction creates deviance

and by applying those roles to particular people and labeling them as outsiders. From this point of view, deviance is not a quality of the act the person commits, but rather a consequence of the application by other of rules and sanctions to an 'offender.' The deviant is one to whom that label has been successfully applied; deviant behavior is behavior that people so label.
While society uses the stigmatic label to justify its condemnation, the deviant actor uses it to justify his actions. He wrote: "To put a complex argument in a few words: instead of the deviant motives leading to the deviant behavior, it is the other way around, the deviant behavior in time produces the deviant motivation

Modified labeling theory
Bruce Link and colleagues have conducted several studies which point to the influence that labeling can have on mental patients. Through these studies, which took place in 1987, 1989, and 1997, Link advanced a "modified labeling theory" indicating that expectations of labeling can have a large negative effect, that these expectations often cause patients to withdraw from society, and that those labeled as having a mental disorder are constantly being rejected from society in seemingly minor ways but that, when taken as a whole, all of these small slights can drastically alter their self concepts. They come to both anticipate and perceive negative societal reactions to them, and this potentially damages their quality of life.
Modified Labeling theory has been described as a "sophisticated social-psychological model of 'why labels matter' ". In 2000 results from a prospective two-year study of patients discharged from a mental hospital (in the context of deinstitutionalization) showed that stigma was a powerful and persistent force in their lives, and that experiences of social rejection were a persistent source of social stress.

Efforts to cope with labels, such as not telling anyone, educating people about mental distress/disorder, withdrawing from stigmatizing situations, could result in further social isolation and reinforce negative self-concepts. Sometimes an identity as a low self-esteem minority in society would be accepted.The stigma was associated with diminished motivation and ability to "make it in mainstream society" and with "a state of social and psychological vulnerability to prolonged and recurrent problems".
There was an up and down pattern in self-esteem, however, and it was suggested that, rather than simply gradual erosion of self-worth and increasing self-deprecating tendencies, people were sometimes managing, but struggling, to maintain consistent feelings of self-worth. Ultimately, "a cadre of patients had developed an entrenched, negative view of themselves, and their experiences of rejection appear to be a key element in the construction of these self-related feelings" and "hostile neighbourhoods may not only affect their self-concept but may also ultimately impact the patient's mental health status and how successful they are".

Drawbacks of labeling theory
This theory doesn’t explain initial causes of deviant behavior so theory has limited usefulnessand.


The Neurodevelopmental Theory of Schizophrenia:
Evidence from Studies of Early Onset Cases
Isr J Psychiatry Relat Sci - Vol. 47 - No 2 (2010)

McDonald C, Murray RM. Early and late environmental risk factors for
Brain Res Rev 2000;31:130-137.

Strain Theory Revisited: Economic Goals, Educational Means, and Delinquency
Margaret Farnworth; Michael J. Leiber
American Sociological Review, Vol. 54, No. 2. (Apr., 1989), pp. 263-274.

(For slide view and download slide presentation, please visit biological-sociological theories ( sania talha )

Special Tag: SANIA TALHA , Sargodha University