I. The biopsychosocial model
The biopsychosocial model proposed by Engel (1977) states that the health of an individual is affected by interactions between biology, society and psychology, a more holistic approach compared to the older biomedical model which only considered an individual’s physical health.
II. Theory of fundamental causes
Link and Phelan (1995) came up with the theory of fundamental causes to explain how social conditions continuously correlated with health disparities despite changes in risk factors (e.g. smoking) and the prevalence of diseases (e.g. polio) over the decades. They reasoned that because social conditions affect several risk factors and therefore underlie a variety of diseases, they are considered “fundamental causes”. Fundamental causes include knowledge, money, power, prestige and social connections.
III. Social influences on biology
Societal influences throughout the life course can affect human biology. Individuals who suffered through the Dutch hunger famine of 1944 were subsequently affected by diseases such as obesity and diabetes, likely through the body’s epigenetic adaptations to a nutrient restricted diet, which could not handle a return to nutrient-rich foods. Their children and grandchildren were also predisposed to such diseases, highlighting the long-lasting impact of short-term stress. Meanwhile, Gesquiere et al. (2011) found high-status savannah baboons had low social control, a lack of social support, and were required to continually reassert their authority, which was linked to dysregulation of cortisol (chronic stress). This mechanism may underlie the increased risk of breast cancer for women with high job authority (Pudrovska et al., 2013).
IV. Socioeconomic inequalities
Socioeconomic inequalities are a major determinant of health. Low socioeconomic status has been demonstrated to affect the psychological health of individuals. Costello et al. 2003 found that income supplements to those in poverty reduced psychiatric illnesses relating to conduct and aggression. Economic adversity also affects biological mechanisms, such as by increasing the affect of genetic risk factors on increased BMI (Liu and Guo, 2015).
V. Implicit bias
Implicit bias is where healthcare provision can be discriminatory without the healthcare provider knowing it is. This affects the health of individuals of certain demographics. For example, doctors are less likely to give opioids to women in pain compared to men (Chen et al., 2008). The same applies for black compared to white patients (Goyal et al., 2015). Discrimination such as racism also affects the mental health of individuals and the socioemotional development of their children (Becares et al. 2015). Most interestingly, racism has been observed to hasten cell ageing (Brody et al., 2016).
VI. Social relationships
Social relationships affect health outcomes. This includes provision of social support, found to account for 25% of variance in survival after leukaemia diagnosis (Pinquart and Duberstein., 2010). In comparison, social isolation is associated with 30% increased odds of stroke (Valtorta et al., 2016). However, the quality of social relationships also matter – suction blisters healed quicker in couples with less hostile relationships (Kiecolt-Glaser et al., 2005). Furthermore, socially distant individuals may affect the health of each other, such as transmission of STIs from one individual to another.
When does a label become a stigma? Link and Phelan (2001) define “stigma” as having five components:
- Distinguishing and labelling
- Unconscious or conscious stereotyping
- “Us” and “Them” separation
- Status loss
- Structural discrimination and discrimination by individuals
The prevalence of psychiatric conditions is much higher among LGBT individuals in those US states with fewer legal protections, and dropped as states legalised gay marriage (Hatzenbuehler et al., 2012, 2013).