Reasons for the Belief that Psychotherapy is Less Effective for Biologically Attributed Mental Disorders

At points, the texts or the materials for participants refer to biological / brain / mental / psychological processes or causes. Although all mental and psychological processes are biological, the uses of these terms are for the sake of brevity and to reflect the typical usage of these terms, not to endorse dualistic reasoning. For instance, “biological causes of mental disorders” refer to genetic risks and brain abnormalities, as opposed to childhood trauma or environmental stressors.

See Wallman and Melvin (2022) for evidence of an association between endorsing biological etiologies and preferring psychotherapy among parents of adolescents with depression when considering treatment for their children.

It is also worth noting that in Iselin and Addis (2003), Lebowitz and Ahn (2014), and Ahn and colleagues (2009), medications were thought to be less effective for treating disorders attributed to psychosocial etiologies. While this is also worth investigating, the current study focuses solely on the effect of biological explanations on the perceived effectiveness of psychotherapy because the trend appears to be towards describing mental disorders in biological terms (again, Deacon 2013; Lebowitz, 2019; Pescosolido et al., 2010; Pilkington et al., 2013; Salm et al., 2014).

Depression was chosen as a target disorder because it is among the most prevalent mental disorders, affecting more than 8% of the U.S. adult population (National Alliance on Mental Health). Partly due to its prevalence, depression is also familiar among lay people, making it easier for participants in this study to understand our reading materials and questions.

Mturk Toolkit recruits and interfaces with Mturk workers, but independently collects demographic information over time, and provides more protections against poor-quality workers (i.e., by blocking workers with hidden locations, running VPN checks and creating anonymized CloudResearch IDs for respondents. Participants completing this survey did so in an average of 8.40 min and the survey was advertised as taking 10 min or less. To help ensure data quality we used two captchas at the start of the survey, one asked participants to select a box with the label, “I’m not a robot” and a second captcha asked participants to select “all statements that are true” with four options including 1) “the earth is flat”, 2) “the sun revolves around the Earth”, 3) 3 + 5 = 8 and 4) “plants need water to grow”. Respondents who failed either captcha did not proceed to the survey.

Although the current study’s focus is on perceptions of psychotherapy, perceptions of medication were measured to ensure replicability of previous findings.

Although the materials referred to chemical imbalances and amygdala activation, we recognize that these theories of depression have been scrutinized and sometimes discredited (e.g., respectively, Moncrieff et al., 2022; Grogans et al., 2022). The inclusion of these theories should not be seen as endorsement of them, but rather as a way of providing lay participants with accessible information, as such theories have been popularized over many years (e.g., Pescosolido et al., 2010), are still implied in practice (e.g., SSRI), and are still debated (again, Moncrieff et al., 2022). Future work should modify the materials using current theories of depression.