Natalie Staats Reiss, Ph.D., and Mark Dombeck, Ph.D.
In addition to suicidal thoughts, there are other warning signals that suggest suicide risk as well as the possible presence of a mental or physical illness. Of particular concern are signs and symptoms that are changes from a person's normal behavior, appearance, and functioning.
Additional warning signs of suicide can include:
decreased performance in school or work
an unusual desire for social isolation
a significant decrease in self-esteem
increased emotionality (expressed as anger, agitation, anxiety, hopelessness, sadness, or similar emotion)
a sudden decrease in emotionality; particularly, a movement from depression or agitation to remarkable and uncharacteristic calm
uncharacteristic behaviors or emotions
uncharacteristic carelessness concerning personal safety
increased drug and/or alcohol use
losing interest in things that someone used to enjoy
failing to take prescribed medications or follow required diets
preparing for death by getting one's affairs "in order"
Excessive behavioral changes in any direction (e.g., towards agitation or towards calmness) beyond what might normally be expected following a loss or emotional insult are worth pointing out and exploring with a potentially suicidal person. For example, people who are recovering from depression should be watched for possible suicide warning signs during the period of their recovery. An increase in their energy level can provide the ability to act upon suicide thoughts they've been nursing while depressed but were too exhausted to do anything about.
Similarly, sudden and uncharacteristic calm after a period of depression or agitation can come on as a result of people having made the decision to kill themselves. People may become calm because they believe that their impending death will finally solve their overwhelming problems. In a similar way, any person who suddenly begins arranging their affairs and "tying up loose ends" (e.g., giving away personal items) or makes plans to move after having experienced a period of depression and severe personal struggle may actually be planning suicide.
In following up on such changes with a potentially suicidal person, keep in mind that your concern will in some cases represent a false positive concern. There may be no actual suicidality present. It is important to follow up anyway, given how important it is to identify actual suicidal intent before it progresses towards an actual suicidal attempt.
Suicidality generally progresses from idea, to plan, to actual attempt. Once seriously suicidal people have decided to end their lives, they will generally start assembling a "suicide kit" by gathering those necessary tools and ingredients to accomplish their goal. For instance, people who have decided to overdose on pills may start stockpiling medicine. People who decide to shoot themselves may need to purchase a gun or ammunition. Attempts to obtain tools that might be used for suicide can then also become a warning sign for significant suicide risk. This can be a difficult warning sign to spot as many such tools are common household items, and many homes already have guns in them.
People whose level of suicidality has progressed to the point where they are presently engaged in assembling the means of their suicide are in acute, immediate, and substantial danger of harming themselves. If you observe someone possibly assembling the means to end his or her life, that person's suicide risk level has become extremely high. The time to ask about suicidality is right now. The time to drive the suicidal person to the hospital may be now as well.
Warning signs for suicide are not typically obvious and can be very difficult to spot in advance. If you are reading this information after your friend or family member has already attempted or committed suicide, don't beat yourself up if you missed what now seem like obvious warning signs. It is usually far easier to recognize warning signs later on than to catch them prior to a suicide attempt being made. You are not stupid, insensitive, and/or clueless if you didn't know that someone was suicidal. Even the best trained mental health professionals can miss some suicidal warning signs, particularly if those signs are very subtle.