Depression has long been the prime suspect in cases of suicidal behavior, but a new study implies that many mental illnesses contribute to the risk of suicide and self-harm and that impulsive behavior is perhaps the most influential variable.

 

It's true that approximately half of all subjects who've considered suicide and slightly more than half of those who complete the act have been diagnosed with some sort of recurring mental illness. A large scale study based on World Health Organization Mental Health Survey data drawn from more than 100,000 people in 21 countries worldwide concludes that, while severe depression is perhaps the most accurate predictor of suicidal thoughts, other disorders play a larger role in determining whether subjects act on those impulses. The most influential of these are conditions that create chronic states of high anxiety and lapses in self-control: schizophrenia, PTSD, and social anxiety disorder are the best-known examples.

 

Each disorder considered in the study corresponded with a higher suicide rate among affected subjects. Comorbid disorders also led to considerably higher suicide rates, reinforcing the theory that subjects with multiple illnesses should not be treated for each condition in turn but rather for the cumulative effects of all conditions. Treated a depressed and chronically anxious subject with simple antidepressants will not reduce the likelihood of suicide because every related condition raises the probability of self-harm. The influence of each individual disorder on subsequent suicide attempts remained strong even after researchers controlled their data for comorbidity, with panic disorder bearing the greatest influence on subsequent suicide attempts. This finding implies that even though many severely depressed individuals repeatedly entertain thoughts of suicide, they are usually able to rationally decide against acting on their impulses.

 

The survey also found that, while rates of mental illness were lower for subjects living in developing and third-world countries, affected subjects were considerably more likely than their western peers to take their own lives. This finding may stem from the fact that mental health issues receive far less attention in these cultures and that subjects are therefore less likely to seek treatment. An unrelated study found that age plays a pivotal role in determining which subjects who receive anti-depressant treatment will also attempt suicide: subjects under the age of 25 are considerably more likely to harm themselves if they've been diagnosed and treated for depression, while suicide rates among older subjects remain the same.

 

The larger points to be drawn from both these studies are that depression and anti-depressant medications are only two of the innumerable factors in the self-harm/suicide equation and that a subject to whom multiple variables may apply is at greater risk. According to these studies, a young adult living in the developed western world who has been diagnosed and treated for comorbid mental health problems will be most likely to consider and attempt suicide. Subjects suffering from severe depression should be closely monitored for suicidal ideation, but others who've been diagnosed with rarer conditions like schizophrenia, bipolar disorder and panic disorder face even greater risks, and their treatment plans must cover all variables.