Psychiatry Advisor: Although health professionals have invested significant effort toward reducing the rate of suicide in the United State, the rates do not appear to have declined. Could you help us to understand the gap between the efforts and the actual rates of suicidal ideation and attempted suicide?
Dr Oquendo: There are a number of open questions to that effect. One thing we have seen is a cohort effect whereby rates of depression are increasing in the population. But it is important to stress that depression is only one of the things that predispose people to suicidal behavior. What is concerning, though, is that as you see an increase in rates of depression, you are also going to observe an increase in rates of suicide. This is why intervening before people become fully symptomatic might be very helpful in terms of stemming that tide. In addition, questions have been raised about whether we are simply getting better at identifying suicide. As some of the stigma surrounding suicide abates, people are becoming able to talk more freely about it. In addition, medical examiners and coroners might be more willing to label a death a suicide now that there have been many barriers removed. Until recently, insurance companies would not routinely pay out life insurance if suicide was involved; as I am sure you can imagine, this would motivate families to work in concert with the medical examiner to ensure that another cause of death was reported. Therefore, changes in societal beliefs and values may be affecting the rates.
Thirdly, what has been very concerning is the increasing rates of suicidal behavior among young girls. It is possible that this is tied to the early onset of puberty. Over the past 50 years, we have seen earlier and earlier onset of puberty. The downward trend seemed to have slowed down over the past 10 to 15 years; however, the age seems to be going down again. Although there are childhood anxiety and depressive disorders, usually you don’t see the emergence of psychiatric disorders until the onset of puberty. Therefore, with earlier-onset puberty, you may see earlier-onset psychiatric conditions that in turn might be contributing to the increase in suicidal behavior in young girls.
Psychiatry Advisor: What do you think are the implications of neuroscience and neurobiology research in identifying individuals with suicidal intent?
Dr Oquendo: We recently had a paper accepted for publication in which we used positron emission tomography (PET) imaging to identify individuals who may have not only greater intent, but who may have more lethal suicidal behavior in the future. Although this is not yet ready for implementation in the clinic, developing biomarkers that can serve to identify individuals at very high risk is something we can attain. It obviously takes some concerted research efforts and we will continue to work on that. I believe that brain imaging modalities are going to be one of the most tractable ways to address this problem. We may be able to examine how people use parts of their prefrontal cortex to harness control over their emotions, as the inability to regular one’s own emotions is a very clear risk factor for acting on suicidal thoughts.
Psychiatry Advisor: What are your future research plans?
Dr Oquendo: We recently received notice of a grant award from the National Institutes of Mental Health to conduct research focused on identifying 2 different subtypes of suicidal behavior. One is a subtype that has more aggressive impulsivity; these individuals react to things in the environment with a very large increment of hostility followed by suicidal ideation. These individuals appear to complete suicide “out of the blue,” with little awareness by others that there is anything going one. The other subtype is a deeply depressed, ruminative, chronically suicidal individual. Now, you may not be able to predict where or when that individual is going to attempt suicide, but they have a much more deliberate approach toward doing it. In addition, they typically engage in much more lethal behavior. These individuals have amazing cognitive control. For example, if you were to administer psychological tests, they do better than average. They also tend to be low aggression individuals. So, it is a very different manifestation. As this is our first look at this, it may be quite possible that we will find many more subtypes. Whatever the outcome, it is a very promising way of looking at this problem.
Click here for more research from the 2016 Annual Meeting of the American Psychiatric Association.