Prozac During Adolescence Triggers Long-Term Effects

May 1st, 2012   |  

Major depressive disorder (MDD) is more prevalent in the pediatric population than previously believed. According to some estimates, between 2% and 8% of children and adolescents have mood disorders. Depression in childhood often predicts recurrent episodes of depression later in life. This population is also at heightened risk of psychiatric disorders, substance abuse, social maladjustment, homelessness, and criminality. Clearly, depression in young people is not a problem that can be safely ignored. Early therapeutic intervention is essential and usually consists of cognitive-behavioral therapy and medication. Currently, the only antidepressant medication approved for use in children and adolescents is Prozac (fluoxetine). However, the lasting effects of Prozac exposure during youth are still not completely known. Conventional wisdom suggests that the benefits of treatment likely outweigh long-term risks, particularly in cases of MDD.

The adolescent brain, just like the adolescent body, experiences profound and rapid development. Chemicals in the brain called neurotransmitters direct cellular and structural growth throughout the brain, and this process gives rise to the adult brain: a well-regulated, stable organ that manages consciousness and the central nervous system. During the period of rapid growth, any disruptions or chemical stimuli can lead to functional changes later in life. For this reason, antidepressant use in childhood has come under great scrutiny. Prozac alters the balance of neurotransmitters in the brain. Some have argued that Prozac exposure during adolescence may result in lasting, even permanent behavioral changes. Researchers conducted a controlled experiment with adolescent rats to address some of these issues.

Rats given Prozac during adolescence displayed significant behavioral changes when tested as adults. For example, they showed less response in a forced-swim test and more response to anxiety-producing situations, such as a new environment. The increased anxiety was reduced by a second exposure to Prozac. Most disturbingly, sexual behavior in adulthood was impaired by Prozac taken during adolescence. This finding was completely unexpected. However, the researchers cautioned that the relationship between brain development and behavior is enormously complicated, and the current study only highlights this complexity. How much of these results translate to humans is also an open question. Rats are typically used in these studies because they mimic human physiology and neurobiology. Still, the underlying mechanisms of behavior are not well understood.

The adolescent rat study, among others, adds powerful evidence to the argument that Prozac initiates profound changes in the brain. These changes manifest themselves as behavioral and mood alterations. Human research is necessary to determine the scope of these alterations. As it stands, prescription of this antidepressant for children with MDD is still warranted.

References

  1. PubMed Health. [Internet]. (n.d.). Bethesda (MD): National Library of Medicine. Fluoxetine. Retrieved April 11, 2012, from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000885/
  2. Iniguez, S. D., Warren, B. L., Bolanos-Guzman, C. (2010). Short- and long-term functional consequences of fluoxetine exposure during adolescence in male rats. Biological Psychiatry, 67(11), 1057-1066.