SSRIs (Selective serotonin reuptake inhibitors) are a group of medications that are commonly used for the treatment of depression and some other mental health issues (as described here). Whilst some research [here] suggests that generally, SSRI use does not increase suicidal behaviour, anecdotal reports [here] indicate that some people are adversely affected and can, as a result, feel more suicidal. If you experience any troubling side effects, speak to your doctor immediately.