Cannabinoid Modulation of Amygdala Reactivity to Social Signals of Threat in Humans

Phan et al. have carried out good research to shed light on the significant impact of THC on amygdala reactivity to social signals of threat in humans. This growing evidence of cannabinoid modulation of anxiety in humans also provides evidence for the anxiolytic effects of THC, and some propose the “development of new therapies that act on cannabinoid systems to modulate fear behaviors in neuropsychiatric disorders such as social phobia, autism, and schizophrenia, in which social fear or withdrawal, and aberrant reactivity to threat are cardinal features” (p. 2317). Even if these results are promising in neuroscience, however, some doubts exist about the real impact of these findings in exploring novel therapeutic strategies for social phobia or fear. Taking into account a biopsychosocial framework (1) for comprehension and treatment of mental disorders, the need to recognize many factors (psychological variables, family and social context, living habits, etc…) in the etiology and treatment of many disorders has to be considered. If a problem is generated at a cultural, social, interpersonal, family level, perhaps the best treatment is to provide healthcare at the same level. If a problem is generated at the biological, molecular, or neurological level (probably in a very severe anxiety problem), perhaps the best choice for treatment is to consider this level. If a person shows an anxiety problem only in some particular and selected situations and contexts (such as at work but not in the family, alone but not with people, etc…), is the bio-neuro-pharmacological approach the best explanation and treatment? Moreover this approach might not be as specific as we usually think: according to Moncrieff and Cohen (2), “an alternative “drug-centred” model can better explain observed drug effects in psychiatric conditions. This drug-centred model suggests that instead of relieving a hypothetical biochemical abnormality, drugs themselves cause abnormal states, which may coincidentally relieve psychiatric symptoms ... Alcohol's disinhibiting effects may relieve symptoms of social phobia, but that does not imply that alcohol corrects a chemical imbalance underlying social phobia” (p. 961). In conclusion, psychopharmacologic and cognitive-behavioral treatments are well-established treatments for anxiety disorders, panic disorder, social anxiety disorder, generalized anxiety disorder, etc... (3) but a biopsychosocial framework is required to better target the right level of intervention (and explanation). References 1. Rolland JS, Williams JK. Toward a biopsychosocial model for 21st-century genetics. Fam Process 2005;44:3-24. 2. Moncrieff J, Cohen D. Do antidepressants cure or create abnormal brain states? PLoS Med 2006;3:e240. 3. Shearer SL. Recent advances in the understanding and treatment of anxiety disorders. Prim Care 2007;34:475-504, v-vi.