¶ … social structures exert a definite pressure upon certain persons in the society to engage in nonconformist rather than conformist conduct," (Merton, 1938, p. 672). With his own italics emphasizing the stress and strain that social structures can produce in the individual, Robert Merton outlines the basis of strain and stress theories. Stress is a natural part of life; it is how people cope with stress or react to it that matters most. Individual differences in background, situational variables, and also personality and psychological traits can also impact how people deal with stress and respond to stressors. However, some people will naturally encounter more stressors and more strain than others. Merton and other sociologists who recognized the value of strain theory showed how poverty and other structural variables cause stress and strain, and can often be the cause for behavioral problems including criminality. Yet once a person has been labeled a "deviant," a "nonconformist," or a "criminal," it can be harder than ever before to mitigate stress. Labeling theory suggests that social stigmas add an additional layer of stress or strain, compounding preexisting problems like poverty or abuse. Stress theory explains how different people deal with stress differently. There are several approaches and applications for stress theory. One is to focus on the critical and stressful life events, such as a death of a loved one, job change, or divorce. These are life events that most people encounter, and by recognizing that a stressful life event has occurred, the person or people affected can work to maximize their resources and coping strategies (McLeod, 2010). Stress theory also addresses the chronic strains that some members of the population do experience, including poverty, racism, or stigma. Chronic strain is much different from stressful life events, which are one-time situations. Chronic strain is experienced every day, and can be especially dangerous. Finally, stress theory shows that coping resources are unequally distributed in the population. Poor people will have less access to mental health resources, for example. Crucial to understanding stress theory is recognizing the role that coping mechanisms and adaptations play in mitigating stress. People who have access to a strong social support system, or who have access to mental health counseling, might be able to cope with sudden stress such as critical life events. Others might resort to adaptations such as using drugs.

Structural strain refers to Merton's analysis of social deviance based on external or situational variables, social hierarchies and power structures in particular. Deviance is framed as a response to social strain, experienced mainly as individuals feel frustrated at being unable to achieve upward social mobility or extricate themselves from poverty (Agnew & Scheuerman, 2015). However, poverty is not the only cause of social strain. Any instance in which a person does not live up to societal norms might experience strain. Generally, though, strain theory focuses on deviant or criminal behaviors as being adaptations to role conflict and other problems associated with unequal power distribution in the society. Social structures determine many types of power, including patriarchal power in which women are systematically disenfranchised, or economic power, in which the rich can more easily find access to the means to make more money whereas the poor lack the social, cultural, or financial capital to invest in their future.

Labeling theory is also critical for understanding deviant or criminal behavior. Early labeling theorists recognized the important difference between individuals who commit one-time crimes or occasionally act in deviant manners, and those whose behavior is more chronic. Labeling theory can account for the differences between these two types of people. If a person does not have a self-concept as someone who is deviant, then he or she may be less likely to repeat criminal or deviant behaviors. On the other hand, a person who has been labeled as "bad" or a "criminal" might internalize that into the self-concept and start behaving in ways that conform to that identity ("Labeling Theory," n.d.). Tertiary deviance is a psychological extension of secondary deviance, whereby the person starts to not only identify with being "a criminal," but also ceases to buy into the social norms that censure criminal behavior. The person starts to justify deviant or criminal behavior by claiming that what they are doing is either not wrong at all or even beneficial. In other cases, the person might use clever tactics to manipulate their behavior to make it seem normal, which might happen in cases involving white collar crimes. Tertiary deviance might also describe the rationalities and justifications...

Yet generally there will be some sociological component to mental illness because each person is affected by external variables. Not all mental illnesses are genetic or caused by psychological issues, which is why sociological variables like stress, strain, and labeling need to be taken into account. In many situations, all three of these sociological variables may influence the development of mental health issues. For example, both stressors and structural strain can lead to mental illness in some people who lack the internal or external, social or financial, resources for adapting or coping and who have already been labeled as being deviant. According to stress theory, mental illnesses or problematic behaviors result specifically from the inability to cope effectively with stressful life events or chronic stress. Every person is exposed to stressors, but not all people will respond in the same way. Furthermore, not all societies present individuals with adequate means to address stress.
According to structural strain theory, mental illness can result from the inability for people to achieve socially desirable goals. Research has shown that to some degree, deviant behaviors ranging from suicide and bullying to eating disorders may be related to structural strain (Agney & Scheuerman, 2015). For example, some eating disorders are caused by a person's desire to conform to the society's beauty norms. Bullying can be conceptualized as an aggressive response to the strain of not feeling socially adequate. Being frustrated at not being able to attain promotions at work, coupled with financial stress, could lead a person to commit suicide. The originator of strain theory, Robert Merton, postulated that strain is more likely to occur in places like the United States, which claim to be a meritocracy but which really is not. The American Dream creates strain because the society sends messages suggesting that anyone can achieve their dreams. In reality, institutionalized racism and other factors prevent the American Dream from being fulfilled. This can lead to depression and other mental illnesses. A society that offers less hope for poor people might not have the same rate of mental illness because the poor people in that society do not expect to succeed and therefore do not strain in order to do so.

Labeling theory may also be linked to mental illness. If a person is labeled as being mentally ill, that person might internalize that label, compounding the problem because mental illness becomes part of that person's identity, making it more difficult for them to change. The label might also become a badge of honor for some people, or a marker of their belonging to a special social group like a gang. According to labeling theory, some low-status groups of people will be more likely to be labeled as deviant or are perceived as being deviant. Thus, law enforcement might presume an African-American person is up to no good just by walking down the street or driving a car. Internalization of the label could lead to some people actually fulfilling the expectations that they are deviant. Labels perpetuate preexisting problems.

Life events and environmental factors contribute to stress. Some of the most critical life events that contribute to stress include marriage or divorce, loss of a job, or a death in the immediate family (McLeod, 2010). For some people, the emotional intensity of these events will wear off after some time. Yet for other people, the stress is too much to bear. If multiple critical life events occur at once, and the person lacks internal psychological or external social or financial resources, the experience of stress could take its toll on mental and physical health. Other external or environmental factors that can contribute to stress include things like living in a disorganized neighborhood in which there is little hope for change, or living in a society with strict social norms that prevent someone from achieving their goals such as being a woman in a strongly patriarchal society. Institutionalized racism and structural inequities can cause stress, strain, and maladaptive practices ranging from addiction to mental illness.

Conclusion

Sociological explanations for mental illness include stress theory, structural strain theory, and labeling theory. Stress theory shows how the inability to cope with daily or chronic stress can cause behavioral problems, deviance, or criminal behavior. Strain theory points to structural variables such as social class stratification as contributing to the genesis of mental illness or deviant behavior.…