The association between brain-derived neurotrophic factor Val66Met variants and psychotic symptoms in posttraumatic stress disorder

Abstract

Objectives. Psychotic symptoms frequently occur in veterans with combat-related posttraumatic stress disorder (PTSD). Brain-derived neurotrophic factor (BDNF) plays a major role in neurodevelopment, neuro-regeneration, neurotransmission, learning, regulation of mood and stress responses. The Met allele of the functional polymorphism, BDNF Val66Met, is associated with psychotic disorders. This study intended to assess whether the Met allele is overrepresented in unrelated Caucasian male veterans with psychotic PTSD compared to veteran controls. Methods. The BDNF Val66Met variants were genotyped in 576 veterans: 206 veterans without PTSD and 370 veterans with PTSD subdivided into groups with or without psychotic features. Results. Veterans with psychotic PTSD were more frequently carriers of one or two Met alleles of the BDNF Val66Met polymorphism than veterans with PTSD without psychotic features and veterans without PTSD. Conclusions. The study shows that veterans with psychotic PTSD carried more Met alleles of the BDNF Val66Met than non-psychotic veterans with PTSD or veterans without PTSD. The results might add further support to the hypothesis that psychotic PTSD is a more severe subtype of PTSD.

Brain‐derived neurotropic factor polymorphisms, traumatic stress, mild traumatic brain injury, and combat exposure contribute to postdeployment traumatic stress

“…However, the Met allele (one and two alleles) of BDNF Val66Met polymorphism may be associated with PTSD severity in veterans (Pivac et al. 2012). …”

Does<b><i> BDNF</i></b> Val66Met Polymorphism Confer Risk for Posttraumatic Stress Disorder?

“…The related studies were conducted in adults among European (Croatia), Asian (South Korea) and American populations (USA and Brazil). In detail, 3 articles [16,19,26] involved healthy individuals as controls, and another 2 papers [14,17] used people who suffered from the same stress as cases but without PTSD symptoms - 1 article [18 ]contained both types of controls and thus were treated separately as 2 studies. In addition, 2 articles [14,17] examined PTSD participants who were exposed to stress/traumatic events from active duty in the army.…”

“…During each stage of screening, the literature articles were clearly identified and a consensus could be established. Finally, 6 articles [14,16,17,18,19,26] were selected. Articles in each selection step are shown in online supplementary figure S1.…”

“…Clinical observations also support that the BDNF Val66Met variant [13] plays a role in PTSD. However, contradictory findings were found in the association studies [14,15,16,17,18,19]. Therefore, we conducted this analysis to estimate the influence of BDNF Val66Met on the risk of PTSD.…”

Trauma, posttraumatic stress disorder and psychosis: etiopatho­genic and nosological implications

“…The main results of these studies show that subjects with PTSD-SP have 1) a higher concentration of platelet serotonin, 2) higher levels of corticotropin-releasing factor in the cerebros pinal fluid, 3) a higher concentration of plasma dopamine beta-hydroxylase, 4) specific deficits in smooth pursuit eye movement, and 5) a higher presence of Met alleles in the BDNF Val66Met polymorphism [94][95][96][97][98] . Likewise, different open clinical trials found that the administration of neuroleptics as a monotherapy for 6-8 weeks reduces symptoms in those subjects with PTSD-SP resistant to conventional antidepressant treatment [99][100][101] .…”