The finding: The authors used systematic review and meta-analysis to study whether depression confers risk of developing cancer. They identified 9 journal articles meeting their inclusion criteria, and found only a small increase in overall cancer risk among depressed patients (OR 1.26). However, when they performed subgroup analyses on the low-quality versus high-quality studies, the high-quality studies no longer showed statistical significance. Among the specific cancer types, depression only conferred a statistically significant risk of subsequently developing lung cancer (OR, 1.47; 95% CI, 1.26–1.72, P<0.001).

Strength and weaknesses: The authors used a rigorous methodology in both the systematic review and meta-analysis components of the study. They defined depression based on clinical diagnosis, which may have served to increase diagnostic accuracy, rather than relying on rating scales. This decision may also have led to an underestimate of actual depressive cases and thus an underestimate of cancer risk. Since depression can lead to high risk behaviors, the authors were cautious to point out that many of the studies identified did not account for this potential confounder.

Relevance: Whether or not depression increases the risk of cancer remains a controversial topic, and one which patients or caregivers may ask physicians about. Zeroing in on those studies with the most methodological rigor, the authors note that this study failed to show that depressive disorders, in their own right, confer an appreciable risk of cancer. This study serves to remind C-L psychiatrists of the important interplay between depression and cancer risk behaviors, timely diagnosis, access to treatment, and quality of life.

The finding: The authors found that among a large sample of Romanian cancer patients surveyed, knowing the diagnosis of cancer was associated with a lower level of depression than not knowing the cancer diagnosis. These results were statistically significant among two separate sample surveys—one in 2006 (n=798) and another in 2014 (n=416).

Strengths and weaknesses: The main strengths are the large sample size and sampling at two separate time points nearly 10 years apart. The biggest limitation is the cross-sectional design, which limits findings to associations, rather than causality.

Relevance: C-L psychiatrists working in psycho-oncology are often faced with requests by families or even patients themselves not to disclose information about a cancer diagnosis. In particular, certain cultures have norms which support this practice. This study adds to the literature on disclosure by providing evidence to refute the claims that being told about a cancer diagnosis leads to depression. Instead, it supports what many of us already see in practice—that most patients are able to cope with even the most devastating news without subsequently developing depression.