Among American men, the suicide rate is about four times higher than among women.
The findings were recently presented at the 28th European College of Neuropsychopharmacology (ECNP) Congress in Amsterdam, the Netherlands.
The study researchers analyzed 2,811 individuals with depression who were a part of the Bridge-II-MIX study - an international study of depression and suicide. All participants were assessed by a psychiatrist using the Diagnostic and Statistical Manual of Mental Disorders (DSM) - the standard classification of mental disorders used by mental health professionals in the US.
Many parameters were studied, including previous suicide attempts, family history, current and previous treatments and the patient's clinical presentations. Psychiatric symptoms, sociodemographic and clinical risk factors for bipolar disorder were also collected. Of the participants, 628 had already attempted suicide.
"The strength of this study is that it's not a clinical trial, with ideal patients - it's a big study, from the real world," says study author Dr. Dina Popovic, a psychiatrist at Barcelona Hospital Clinic and the Clinical Research Institute of Biomedical Research in Spain.
Suicide is the 10th leading cause of death for Americans, according to the American Foundation for Suicide Prevention.Among American men, the suicide rate is about four times higher than among women. The suicide rate for Americans is also higher in white men (14.2 deaths per 100,000) than Native Americans (11.7 deaths per 100,000).
Dr. Popovic says they found that "depressive mixed states" often preceded suicide attempts and that mixed depressive features were associated with hallmarks of bipolarity. She explains:
"A 'depressive mixed state' is where a patient is depressed, but also has symptoms of 'excitation,' or mania. We found this significantly more in patients who had previously attempted suicide, than those who had not. In fact, 40% of all the depressed patients who attempted suicide had a 'mixed episode' rather than just depression."
Patients who suffer from 'mixed depression' are at a much higher risk of suicide
A comparison was made between those who had and those who had not attempted suicide but who were depressed.Risk of attempting suicide is at least 50% higher, the scientists found, if a depressed patient presents any of the following symptoms:
- Risky behavior (for example, reckless driving, promiscuous behavior)
- Psychomotor agitation (pacing around a room, wringing one's hands, pulling off clothing and putting it back on and other similar actions)
- Impulsivity (acting on a whim, displaying behavior characterized by little or no forethought, reflection or consideration of the consequences).
There is an important message here, the study says, for all health care professionals who see patients suffering from depression and who may not pay enough attention to these symptoms. Early identification of symptoms and timely treatment of mixed depressive states could represent a major step in suicide prevention.
Dr. Popovic adds:
"In our opinion, assessing these symptoms in every depressed patient we see is extremely important, and has immense therapeutical implications. Most of these symptoms will not be spontaneously referred by the patient, the clinician needs to inquire directly, and many clinicians may not be aware of the importance of looking at these symptoms before deciding to treat depressed patients."
In a previous report from Medical News Today, a draft recommendation issued by the US Preventive Services Task Force suggested that doctors should screen all adults for depression.