Suicide attempt and externalizing behaviours in posttraumatic stress disorder (PTSD): Possible role of the activating effect of antidepressants

To the Editor

Suicide risk and externalizing behaviours (Shin et al., 2012) in posttraumatic stress disorder (PTSD) can be difficult to manage. Selective serotonin reuptake inhibitor (SSRI) antidepressants including paroxetine and sertraline (Jeffreys, 2009) are the only US Food and Drug Administration-approved pharmacotherapies for PTSD. Many antidepressants, including SSRIs, are known to have an activating effect on mood (Tondo et al., 2010). The two case studies below suggest that antidepressants may enhance the emotional regulation difficulties in PTSD, which in turn may contribute to increased suicidality and externalizing behaviours in some patients. Consent was obtained from the Office of Research Ethics, University of Western Ontario, Canada. Both patients met the DSMIV-TR criteria for PTSD with delayed onset; other psychiatric comorbidities including bipolar disorder were ruled out.

Patient A is a 42-year-old hospital ward clerk who was referred after she impulsively hit and pushed a co-worker. This behaviour was totally out of character for her. She had been started on paroxetine 20 mg daily after a 2 month history of insomnia, nightmares, anxiety, and flashbacks of sexual abuse between ages 5–8 years. Two weeks after starting the paroxetine she reported irritability and panic attacks. On the day of the assault, the smell of aftershave cologne from a visitor reminded her of the cologne used by the perpetrator. She later described that she was triggered, ‘saw red’ and ‘pushed the person in front of her and just wanted to get away’. Management included risperidone one-half mgs tid prn for anxiety and valproic acid for emotional regulation. The dosage of paroxetine was tapered to 15 mg daily.

Patient B is a 45-year-old bookkeeper who was started on sertraline 200 mg after a 3 month history of anxiety, insomnia, nightmares, and intrusive memories of sexual abuse between the ages of 5–9 years. Three weeks after starting the sertraline she reported panic attacks, increased insomnia and intense suicidal thoughts. She planned suicide by driving her car into a cement wall and stopped in the middle of her attempt, while driving, after receiving a cell phone call from her daughter. There was no previous history of suicide attempts. After hospitalization, initial pharmacological management included olanzapine 10 mg qhs to decrease her activation. She was later started on lamotrigine for emotional regulation, and sertraline 150 mg.

Hyperarousal symptoms in PTSD patients (e.g. increasing insomnia, panic attacks, irritability) should be monitored carefully and managed before treatment with antidepressants is initiated.