stress responses and impact on behavior.

stress responses and impact on behavior. Dr.emanabahussain. consultant ,psychiatry department

What is stress? • 1-an aversive stimulus event. • 2-aspecific physiological and psychological response. • 3-aspecial type of transaction between the person and the environment.

Stressors: • Are those life events that induce change in routine . • Or in situations where no change has occurred when change might have been expected.

Stress response and how it influence disease? • in1961 Holms found that the predictors of recovery in pts with Pulmonary TB were: -Strong family ties - Steady employment -Adequate income -Regular recreation. -Job satisfaction He moved from the study of predictors of recovery to predictors of the onset of illness.

1967Holms and Rahe developed the schedule of recent life events , SRE, each one has # of life change units LCU. • They found linear relationship between LCU scores and the # of illnesses experienced. • In a later study they found that illness developed within 2 years in 30%of subjects with lowLCU scors,50% with intermediate scores,80%with high LCU scores.

Most researchers agree that stress-induced illness may be caused by chronic physiological arousal, the final response to stress may be mediated by several factors that can either buffer or intensify the stressors. These are: • Person perception. • Coping style • Social support systems • Degree of genetic vulnerability.

Cognitive appraisal of life change events: • Events that are stressful for one person may not be for another. • Lazarus(1977)has pointed out that stimulus can evoke a stress reaction by psychophysiological means only if it is interpreted by the person as harmful or threatening. • Rose(1980)after stressful life event level of cortisol,caticholamine and GH rise but only catecholamine show arise after events of a pleasurable nature(+ve and –ve life events have diferent physiological consequences.

Coping style and defense mechanisms: • Coping is: behavior that involve special physical and emotional energy and attention that’s required to deal with some difficult circumstances. • It is 2 types: -direct action: when the person tries to master the stress. -palliation: when the person is unable to manage the environmental challenge successfully.

Social support: • Recent research evidence suggests that those who have social supports are protected in crisis from a variety of pathological states(bebbington,1987) • Studies of marital and health status reveal that married have lower mortality rates than those who are single(ortmeyer1974) • Brown and Harris(1978)women with high degrees of stress and little support had 4 times the rate of depression than women with equal degrees of stress but much support.

Biological predisposition to stress induced illness: • Another component in the multifactorial causation of onset of illness is the pt genetic susceptibility. Stress may play a contributing role in causation, but there is no doubt that once the disease is present, symptoms of these disorders can be exacerbated by stress. • On the other hand ,some pts exhibit a biological hardiness that appear to protect them from stress-induced illness.

stressor perception Coping style Genetic vulnerability Social support Psychophysiological changes Acute illness

Psycho physiological pathways: • The hypothalamus act as a central mediator for the regulation of the autonomic, immune, and endocrine systems . • It integrates cortical(cognitive)limbic(emotional) and autonomic(visceral)inputs and control many of the neural and endocrine systems required for homeostasis.

The hypothalamus act as the locus where psychological stress may be converted into physiological function. • It contain the nuclei of the autonomic.n.s)which are grouped into two divisions the sympathatic and parasympathatic) that innervate the viscera and many hormone secreting cells

In response to stress CRF IS SECRETED FROM THE HYPOTHALAMUS it act at the pituitary to trigger release of ACTH which control the serum level of glucocorticoids, their actions can be summarized in the short term as promoting energy use, increasing c.v activity and inhibiting functions such as growth, reproduction, and immunity.

Stressors activate N.A systems in the brain and cause release of catecholamine's from the ANS. • The hypothalamus contains the nuclei of the ANS that innervate the viscera and glands.

The autonomic nervous system:

In acute stress there is a shift from relaxation to arousal i.e. a shift in a whole pattern of hormonal secretions accompanied by an increase in sympathetic discharge, catabolic process and energy mobilization • For a person to remain healthy those periods of arousal must be balanced by periods of relaxation • If stress became chronic no repair of accumulated damage which may lead to illness.

Psycho neuroimmunology: • Part of the stress response consists of the inhibition of immune functioning by glucocorticoids. • CRF stimulate N.A release via CRF RECEPTORS' located on the locus ceruleus which activates the CNS. both centrally and peripherally, and increase epinephrine release from adrenal medulla. • In addition direct links of norepinephrine neurons synapse on immune target cells.

Glaser(1988) examined the immunological function of 75 MD during final exanimation,38 recently separated women and 34 persons giving long term care to relatives with Alzheimer's disease she observed changes in immune cells in all gps,decrease #of T helper cells, and natural killer cells.

both humoral and cell mediated immunity seem to be modulated by stress. • Studies have shown that stressors such as death of spouse or sleep deprivation can alter T cells regulatory pattern and response to mitogens. • Several studies of immunological function have shown that as compared with pts without depression those with M.depression have both reduced # of natural killer cells and diminished natural killer cells capacity.

Behavioral strategies that decrease the influence of stressors continue to show promise in the repair and strengthening of the immune system.

thanks.

stress responses and impact on behavior.