When younger(in my twenties) I noticed that SSRIs initially gave me panic attacks and akathisia. I always had a suspicion that my depression had a degree of bipolarity about it and this study confirms it a little. Activation syndrome is more common among bipolar patients and it consists of the following symptoms:
The components of activation syndrome, as stated by the US Food and Drug Administration, are anxiety, agitation, panic attack, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia, and mania/hypomania. The syndrome is believed to flag suicidality risk in patients taking antidepressants.
If an individual has these symptoms it increases the chance of being bipolar by 3.27 fold.
On multivariate analysis, a bipolar diagnosis was one of only two variables independently associated with activation syndrome, increasing the likelihood 3.27-fold.
The other variable was experiencing a mixed depressed state which like a bipolar diagnosis, increases suicidality. In the past another mood researcher Benazzi, a proponent of ‘mixed depression’, believed that individuals with a few hypomanic traits such as irritability, insomnia and agitation while depressed were more likely to have bipolar disorder.
The other significant variable was being in a depressive mixed state, which raised the likelihood for activation syndrome 4.13-fold. The researchers note that a depressive mixed state is reportedly almost as common in patients with MDD who attempt suicide while on antidepressive treatment as it is in patients with bipolar disorder.
Given the small size of the study and the naturalistic/retrospective nature, further studies are needed to confirm the connection between activation syndrome and bipolarity.