A review of the neurobiological effects of psychotherapy for depression

Although randomized, controlled clinical trials have shown that different forms of psychotherapy may be efficacious for depression, psychotherapy has not been widely reported to have effects upon the neurobiological concomitants of depression in similar ways as medication. Neuroendocrinal changes that occur during depression (principally hypercortisolaemia) produce structural and functional alterations to the prefrontal cortex, hippocampus, and amygdala, plus the connectivity between these regions of the brain. This article reviews the evidence to date regarding the neurobiological effects of psychotherapy for depression and suggests a hypothetical pathway linking the nurturing effects of the therapist-patient " bond" and restoration of neuroendocrinal " balance." This pathway may provide a neurobiological causal link between psychotherapy and alleviation of depression in the same way as that which exists for pharmacological treatments, and argues for a model of depression that includes both biological and psychological effects of psychotherapy when considering treatment choice and application.