Suicidal ideation can be described as the experience of compulsive suicidal thoughts and a general desire to end one's own life. These thoughts patterns and desires range in intensity from fleeting thoughts to an intense fixation. This effect can also create a predisposition to other self-destructive behaviors such as self-harm or drug abuse and, if left unresolved, can eventually lead to attempts of suicide.
Suicidal ideation is often accompanied by other coinciding effects such as depression and motivation enhancement in a manner which maintains the person's negative view on life but also increases their will to take immediate action. It is most commonly induced under the influence of moderate dosages of various antidepressants of the selective serotonin reuptake inhibitor class. However, outside of psychoactive substance usage, it can also occur as a manifestation of a number of things including mental illness, traumatic life events, and interpersonal problems.
If you suspect that you are experiencing symptoms of suicidal ideation, it is highly recommended that you seek out therapy, medical attention, or a support group.