Page 31 - JCBP-3-1

Journal of Clinical and
Basic Psychosomatics BDNF in psychotherapy

namely, baseline BDNF predicts good outcomes, the change serum BDNF levels. However, a larger study with a 6-week
in BDNF correlates with symptom improvement, or BDNF intervention showed significant effects. Schosser et al.
36
at outcome relates to measures of the psychotherapeutic found a strong association between three closely related
response. The reports are summarized in Table 1. SNPs, including rs6265, and treatment response to CBT in
Several studies investigating the effect of 277 individuals with depression. This study identified the
psychotherapeutic techniques (such as CBT and MBCT) in heterozygous genotype of each SNP to be associated with
individuals with depression have shown relatively greater a better response, a consistent result reflecting their close
increases in serum BDNF compared to controls, along with linkage disequilibrium.
greater symptom relief. 26-30 Bruijniks et al. reported that Peters et al. (n = 106) did not find an association
37
baseline measures of serum BDNF, while not significantly between rs6265 genotype and depression scores before or
higher (P = 0.07) in responders to CBT and interpersonal after CBT but observed an interesting association of the
psychotherapy (IPT) and not significantly correlated genotype with resilience. In a controlled investigation of
with depression score after 6 months, demonstrated MBCT in depression, Bakker et al. found no association
38
a significant effect on individuals with high working of several BDNF SNPs, including rs6265, with the effects
memory. However, a proportion of the study participants of the intervention.
were also receiving antidepressant pharmacotherapy, Studies on anxiety disorders have not provided strong
which may have confounded the findings. A study on panic support for the role of the rs6265 SNP in affecting the
disorder indicated that those responding well to CBT had outcomes of cognitive therapies. Lester et al. conducted a
39
significantly higher serum BDNF than poor responders. large controlled study and found no effect of genotype on
31
These studies were generally small, with sample sizes of treatment response, whereas two smaller studies focusing
30 – 80. A larger study of CBT examined 170 people on panic disorder and social anxiety disorder also
32
41
40
with depression and found no significant correlations failed to identify significant associations with treatment
between depression scores and serum BDNF before or response.
after treatment.
In contrast, a study of plasma BDNF found no 2.3. BDNF DNA methylation
significant association with the treatment response to DNA methylation is an epigenetic factor that can influence
IPT in individuals with depression. However, another gene expression, primarily through the enzymatic
33
uncontrolled investigation of changes in plasma BDNF methylation of cytosine residues in CpG sequences
following a 4-day yoga-based meditation reported on DNA, potentially affecting transcription factor
substantial increases in BDNF accompanied by binding. There has been much interest in the possible
improvements in anxiety and depression scale scores. environmental influences on DNA methylation, with risk
34
These authors report concentrations of BDNF in the range factors for psychiatric diseases, such as childhood trauma,
more associated with serum studies, and it seems likely affecting DNA methylation. BDNF has been extensively
42
that clotted blood or plasma contaminated with platelets investigated in this respect across several sequences
was studied here. within the gene. One of these is at a binding site for the
transcription factor cAMP-response element binding
2.2. BDNF genetic polymorphisms protein (CREB), which is an essential component of the
The functionality of the single-nucleotide polymorphism intracellular processes regulating BDNF transcription. 43
(SNP) rs6265 in BDNF is well established. This SNP DNA methylation of BDNF is altered in affective
codes for a val66met change in the pro-BDNF protein, of disorders and schizophrenia, potentially affecting
which the met allelic form exhibits impaired intracellular CREB binding to its recognition site and consequent
trafficking and secretion, affecting memory and BDNF expression. Several studies have identified the
hippocampal neurochemistry. Occasionally, other SNPs relationship of BDNF methylation to antidepressant
35
have been investigated, many of which are in very close treatment response; however, DNA methylation research
44
linkage disequilibrium with rs6265 and thus may have is limited in terms of psychotherapeutic response. Two
36
effects resulting from this val66met change in the protein studies investigated its relationship with psychotherapy
structure of pro-BDNF. for borderline personality disorder but did not identify
13
26
Of the studies identified (Table 2), Bruijniks et al. a significant effect. However, we found no studies relating
did not find any effect of the rs6265 genotype on outcome BDNF methylation to talking therapies for depression or
measures over 6 months after IPT and CBT in 138 people anxiety disorders. This represents a major gap that needs
with depression or a relationship between the genotype and to be addressed in future studies.

Volume 3 Issue 1 (2025) 25 doi: 10.36922/jcbp.4461