Antidepressant drug exposure is associated with mRNA levels of tyrosine receptor kinase B in major depressive disorder

1. Recent studies have provided support for the notion that the high affini ty neurotrophin receptor tyrosine receptor kinase B (trk B) may be involved in the treatment of depression. 2. Using a quantitative RT-PCR approach trk B mRNA levels were determined i n brain material from cerebellum, temporal cortex, and frontal cortex of co ntrol specimen and patients with major depressive disorder, schizophrenia a nd bipolar disorder (15 subjects each). 3. Interestingly, elevated trk B mRNA levels were found in cerebellum (3.6- fold) in patients with major depressive disorder, reaching statistical sign ificance (p=0.03). 4. The major depressive disorder-on drugs group differed from controls (p=0 .006) in the cerebellum. 5. Since only patients with major depressive disorder received antidepressa nts, elevated trk B mRNA levels are possibly related to drug treatment.