The effect of gender was not expected. By itself, gender accounted for 30% of the variance in mRNA expression. This is unlikely to be an artifact for two reasons. First and foremost, all RTPCR reactions were carried out in the same plate using the same set of solutions. Second, we have re-examined our data from our earlier examination of 85 independent lymphoblast lines and found the same effect (P < 0.05, unpublished data). Hence, these differences appear to be real. Further studies will be necessary to determine whether these gender differences have significant effect on clinical status or treatment outcome with selective serotonin reuptake inhibitors.
