‘Reductio ad Absurdum’ Dept.

Depression Study Suggests Model for Neurological Basis of Psychotherapy: ‘A new study has provided preliminary evidence that similar neurobiological mechanisms underlie psychotherapy and pharmacotherapy. The study found an association between genotypic variation in 2 receptors associated with antidepressant response and patients’ responses to cognitive behavioral therapy (CBT).

Specific polymorphisms of HTR2A (a serotonin receptor) and NTRK2 (a receptor for brain-derived neurotrophic factor, or BDNF), as well as their interactions, appear to predict the effectiveness of CBT in patients with unipolar depression.’ (Medscape)

Oh man, is this an unwarranted stretch if I have ever heard one. The fact that a genotypic variation which correlates with antidepressant responsiveness also correlates with responsiveness to a type of talk therapy for depression carries next to no implication that that mechanisms at that receptor underlie the neurobiological response to therapy! I hope it is easy to see that this is an exemplar of the classical fallacy of taking correlation for causation. Through the years, there have been a spate of speculative papers attempting to reduce psychotherapy response to a neurobiological mechanism. Well, duh, all mental events operate via neurons and neurochemicals, right? Surely ‘reduce’, as in reductionism, is the operative word in these attempts.