- One way is that GABA slows down nerve cell activity. GABA allows chloride ions to neurons, slowing the activity of the neuron. This causes relaxation.
- A second way is that GABA also reduces serotonin activity. Serotonin is a neurotransmitter that has an arousing effect, i.e. it stimulates some neurons. People who are depressed have low levels of serotonin and one form of treatment is to take drugs to increase the levels of this neurotransmitter to reduce depression. People with anxiety need to reduce levels of serotonin. GABA reduces serotonin, which then decreases arousal of neurons, causing reduced anxiety.
BZs imitate the activity of GABA and thus reduce arousal of the nervous system and reduce anxiety.
c) To what extent have the effects of stressors been shown to be modified by personality and/or by gender?
Gender
Biological explanations
Taylor et al (2000) suggested that women may be biologically programmed to be less affected by stress, because of the action of the hormone oxytocin. Oxytocin is secreted by men and women as a response to stress. Individuals with high levels of oxytocin are calmer, more relaxed, more social and less anxious. Oxytocin has been shown to lead to maternal behaviour and to affection. This might explain why under stressful situations women seek the support of others, which further serves to reduce their stress levels.
This finding has been supported by Hastrup et al (1980), who found that women showed lowered stress responses when their cardiovascular reactions were tested during the time of their menstrual cycle. At this time their levels of oestrogen (which is released at times of stress in women, and lowers blood pressure) were highest, and therefore it would seem that oestrogen might also be reducing the stress - a biological explanation for why women are less stressful.
Social explanations
Males have social support, more unhealthy habits and more stressful occupations. All of these factors can explains why men are more prone to cardiovascular disorders than women.
In terms of social support, research shows that women are more likely to have confidantes and friends that men, and women report making use of social support networks more than men (Carroll, 1992)
In general, women engage in fewer unhealthy behaviour than men, or at least they use to. Men smoked more and drank more alcohol, which might have explained their higher rates of CHD. Howevere this is changing - women are smoking and drinking more and their CHD rates have risen, where as men are smoking and drinking less, this is leading to a narrowing of the gender gap, and the gender gap in CHD is likely to narrow even more.
Cognitive explanations
Men react to stressful tasks with a higher blood pressure than females. This is because males and females differ in the way they learn to handle social conflict situations. Vogele et al. (1997) suggested that females learn to suppress anger and so show low reactivity in stressful situations, where as when males have to suppress anger, this results in raised blood pressure.
Do females in fact react more than males?
Stone et al (1990 tested the hypothesis that males show greater cardiovascular reactivity to stressors than females. they looked at the effects of two stressors : a video game and cigarette smoking, and 6 measures of stress ( e.g. heart rate, blood pressure). on 5 out of 6 measures females actually had a higher reactivity to both stressors.
Early research on the impact of stress emphasized the ‘fight or flight’ response as being a universal reaction to stressful situations.
Most laboratory studies of physiological reactions in response to stress have been carried out on males.
Likewise, field trials of anti-anxiety drugs have often found that women report more side effects then men when taking these drugs, it has been dismissed as a greater tendency among women to report physical symptoms.
Research by Taylor et al (200) provided support for the contention that gender differences in the reaction to stress may be rooted in air evolutionary history.
The value of the ‘fight or flight’ response to male survival has led to the development of higher levels of cardiovascular performance.
Females are in a biological investment when they are pregnant and nurse their offspring. The maternal investment in offspring should result in the selection of female stress responses that do not jeopardise the health of the female or her offspring and maximize the likelihood that they survive.
Taylor et al’s research found evidence that male and female sex hormones activate behaviours that conform to these predicted gender-related differences in stress reaction.
