Antidepressants can change two aspects of personality that are linked to depression, research finds.
Neuroticism — which is characterised by negative thinking in a range of areas — was reduced in people taking a common antidepressant.
At the same time, people’s extroversion was increased, making them feel more outgoing and sociable.
Extroversion is also linked to feeling more positive emotions.
The antidepressant tested in the study is called paroxetine, which is known commercially as Paxil and Seroxat, among other names.
The studies authors write:
“Patients taking paroxetine reported 6.8 times as much change on neuroticism and 3.5 times as much change on extraversion as placebo patients matched for depression improvement.”
For the study, 120 depressed patients took paroxetine and were compared to people given cognitive therapy and a placebo over 12 months.
All three groups saw improvements, even the placebo group.
However, only those taking the antidepressant experienced changes to their personality.
They authors explain:
“Neuroticism and extraversion are 2 of the 5 primary personality dimensions in the Five-Factor Model of Personality.
Neuroticism refers to a tendency to experience negative emotions and emotional instability; extraversion encompasses social extraversion, dominance, and a tendency to experience positive emotions.”
While antidepressants can be effective, still relatively little is known about how they work.
The study’s authors write:
“One possibility is that the biochemical properties of SSRIs directly produce real personality change.
Furthermore, because neuroticism is an important risk factor that captures much of the genetic vulnerability for major depressive disorder, change in neuroticism (and in neurobiological factors underlying neuroticism) might have contributed to depression improvement.”
The study was published in the journal Archives of General Psychiatry (Tang et al., 2009).