The prevalence and mediators of suicidal ideation in patients with chronic con-cancer pain

There is growing concern regarding the epidemic of “unintentional” opioid-related overdoses. However, depression is a common comorbidty with chronic pain with prevalence ranging from 25% to over 80 % depending on the population sampled. There is a moderate level of published evidence suggesting a high prevalence of suicidal ideation (SI) in pain patients. Several risk factors identified as potential mediators include pain location (low back and diffuse), co-occurring insomnia, high pain intensity and long duration. Many of the studies have methodological weaknesses such as small sample size not allowing for stratification, retrospective study design or possible sampling bias. The specific aim of this study was to assess the prevalence of suicidal ideation and identify potential mediators in a large sample (466) of patients with chronic non cancer pain (CNCP). The study design was a retrospective chart review of 466 patients with CNCP treated in a behaviorally based pain program. Data collected included the Brief Pain Inventory, Beck Depression Inventory-Fast Screen for Medical Patients, demographics and results of an independent psychological evaluation. Results indicated a high rate of SI (20%). Logistic regression analysis revealed that history of sexual/ physical abuse (Beta=0.825; p<0.020; OR=2.657 [95% CI=1.447-4.877]), family history of depression (Beta=0.471; p<0.006; OR= 1.985 [95% CI= 1.234-3.070]) and being socially withdrawn (Beta=0.482; p< 0.001; OR= 2.226 [95% CI= 1/413-3.505]) were predictive of SI. These results are consistent with the interpersonal theory of suicide suggesting that social isolation is one factor in predicting suicidal ideation. Family history of depression and personal history of abuse may make certain patients more vulnerable to the effect of chronic pain and increase the risk of suicidal ideation. Developing sensitive measures of risk for suicide in this patient population is discussed. Future research needs to include prospective studies in the general population.