The association between antidepressant use and depression eight years later: a national cohort study

Priorities among effective clinical preventive services in British Columbia, Canada

Background

Despite the long-standing experience of rating the evidence for clinical preventive services, the delivery of effective clinical preventive services in Canada and elsewhere is less than optimal. We outline an approach used in British Columbia to assist in determining which effective clinical preventive services are worth doing.

Methods

We calculated the clinically preventable burden and cost-effectiveness for 28 clinical preventive services that received a ‘strong or conditional (weak) recommendation for’ by the Canadian Task Force on Preventive Health Care or an ‘A’ or ‘B’ rating by the United States Preventive Services Task Force. Clinically preventable burden is the total quality adjusted life years that could be gained if the clinical preventive services were delivered at recommended intervals to a British Columbia birth cohort of 40,000 individuals over the years of life that the service is recommended. Cost-effectiveness is the net cost per quality adjusted life year gained.

Results

Clinical preventive services with the highest population impact and best value for money include services that address tobacco use in adolescents and adults, exclusive breastfeeding, and screening for hypertension and other cardiovascular disease risk factors followed by appropriate pharmaceutical treatment. In addition, alcohol misuse screening and brief counseling, one-time screening for hepatitis C virus infection in British Columbia adults born between 1945 and 1965, and screening for type 2 diabetes approach these high-value clinical preventive services.

Conclusions

These results enable policy makers to say with some confidence what preventive manoeuvres are worth doing but further work is required to determine the best way to deliver these services to all those eligible and to establish what supportive services are required. After all, if a clinical preventive service is worth doing, it is worth doing well.

The validity of the severity-psychosis hypothesis in depression

BACKGROUND

Psychotic depression (PD) is classified as a subtype of severe depression in the current diagnostic manuals. Accordingly, it is a common conception among psychiatrists that psychotic features in depression arise as a consequence of depressive severity. The aim of this study was to determine whether the severity of depressive and psychotic symptoms correlate in accordance with this "severity-psychosis" hypothesis and to detect potential differences in the clinical features of PD and non-psychotic depression (non-PD).

METHODS

Quantitative analysis of Health of the Nation Outcome Scales (HoNOS) scores from all patients admitted to a Danish general psychiatric hospital due to a severe depressive episode in the period between 2000 and 2010 was performed.

RESULTS

A total of 357 patients with severe depression, of which 125 (35%) were of the psychotic subtype, formed the study sample. Mean HoNOS scores at admission differed significantly between patients with non-PD and PD on the items hallucinations and delusions (non-PD=0.33 vs. PD=1.37, p<0.001), aggression (non-PD=0.20 vs. PD=0.36, p=0.044) and on the total score (non-PD=10.55 vs. PD=11.87, p=0.024). The HoNOS scores on the two items "depression" and "hallucinations and delusions" were very weakly correlated.

LIMITATIONS

Diagnoses were based on normal clinical practice and not formalized research criteria.

CONCLUSIONS

The symptomatology of PD and non-PD differs beyond the mere psychosis. Furthermore, severity ratings of depressive and psychotic symptoms are very weakly correlated. These findings offer further support to the hypothesis stating that the psychotic- and non-psychotic subtypes of depression may in fact be distinct clinical syndromes.

Predictors of long-term prognosis of depression

BACKGROUND

Many people with depression experience repeated episodes. Previous research into the predictors of chronic depression has focused primarily on the clinical features of the disease; however, little is known about the broader spectrum of sociodemographic and health factors inherent in its development. Our aim was to identify factors associated with a long-term negative prognosis of depression.

METHODS

We included 585 people aged 16 years and older who participated in the 2000/01 cycle of the National Population Health Survey and who reported experiencing a major depressive episode in 2000/01. The primary outcome was the course of depression until 2006/07. We grouped individuals into trajectories of depression using growth trajectory models. We included demographic, mental and physical health factors as predictors in the multivariable regression model to compare people with different trajectories.

RESULTS

Participants fell into two main depression trajectories: those whose depression resolved and did not recur (44.7%) and those who experienced repeated episodes (55.3%). In the multivariable model, daily smoking (OR 2.68, 95% CI 1.54-4.67), low mastery (i.e., feeling that life circumstances are beyond one's control) (OR 1.10, 95% CI 1.03-1.18) and history of depression (OR 3.5, 95% CI 1.95-6.27) were significant predictors (p < 0.05) of repeated episodes of depression.

INTERPRETATION

People with major depression who were current smokers or had low levels of mastery were at an increased risk of repeated episodes of depression. Future studies are needed to confirm the predictive value of these variables and to evaluate their accuracy for diagnosis and as a guide to treatment.