The status of the sensitization/kindling hypothesis of bipolar disorder

Risk factors of cycle acceleration in acutely admitted patients with bipolar disorder

OBJECTIVE

To identify risk factors associated with cycle acceleration (CA), that is, progressive decrease in duration of syndrome-free intervals between affective episodes, in acutely admitted patients with bipolar disorder (BD).

METHOD

All patients (n = 210) with BD I (67%) and BD II (33%) (DSM-IV) acutely admitted to a hospital serving a catchment area were compared in retrospect with regard to a positive or negative history of CA. Putative risk factors of CA with a P-value <0.05 in uni-variate tests were secondly entered into a logistic regression model.

RESULTS

The logistic regression model was statistically significant (P < 0.0001) and explained between 45.3% and 60.5% of the variance of CA status. 83.7% of the cases were correctly classified with a sensitivity of 87.2% and a specificity of 80.4%. Unique significant risk factors of CA were increasing severity of affective episodes (odds ratio (OR) = 28.8), BD II (OR = 3.3), hypomanic/manic episode induced by an antidepressant and/or alcohol (OR = 3.3), and female gender (OR = 3.1).

CONCLUSION

The clinical factors associated with CA may help targeting patients with BD with a course aggravation, and are in line with previously reported neuropathological processes of illness progression.

The threshold bias model: a mathematical model for the nomothetic approach of suicide

BACKGROUND

Comparative and predictive analyses of suicide data from different countries are difficult to perform due to varying approaches and the lack of comparative parameters.

METHODOLOGY/PRINCIPAL FINDINGS

A simple model (the Threshold Bias Model) was tested for comparative and predictive analyses of suicide rates by age. The model comprises of a six parameter distribution that was applied to the USA suicide rates by age for the years 2001 and 2002. Posteriorly, linear extrapolations are performed of the parameter values previously obtained for these years in order to estimate the values corresponding to the year 2003. The calculated distributions agreed reasonably well with the aggregate data. The model was also used to determine the age above which suicide rates become statistically observable in USA, Brazil and Sri Lanka.

CONCLUSIONS/SIGNIFICANCE

The Threshold Bias Model has considerable potential applications in demographic studies of suicide. Moreover, since the model can be used to predict the evolution of suicide rates based on information extracted from past data, it will be of great interest to suicidologists and other researchers in the field of mental health.

The role of psychosocial stress in the onset and progression of bipolar disorder and its comorbidities: The need for earlier and alternative modes of therapeutic intervention

Psychosocial stress plays an important role at multiple junctures in the onset and course of bipolar disorder. Childhood adversity may be a risk factor for vulnerability to early onset illness, and an array of stressors may be relevant not only to the onset, recurrence, and progression of affective episodes, but the highly prevalent substance abuse comorbidities as well. A substantial group of controlled studies indicate that various cognitive behavioral psychotherapies and psychoeducational approaches may yield better outcomes in bipolar disorder than treatment as usual. Yet these approaches do not appear to be frequently or systematically employed in clinical practice, and this may contribute to the considerable residual morbidity and mortality associated with conventional treatment. Possible practical approaches to reducing this deficit (in an illness that is already underdiagnosed and undertreated even with routine medications) are offered. Without the mobilization of new clinical and public health approaches to earlier and more effective treatment and supportive interventions, bipolar illness will continue to have grave implications for many patients' long-term well being.