Risk of non-Hodgkin lymphoma in relation to tricyclic antidepressant use

We investigated the relationship between use of tricyclic antidepressants (TCAs) and risk of non-Hodgkin lymphoma (NHL). Previous studies provided some evidence of an association, but did not assess risk of NHL subtypes.

Cases and controls were members of Group Health, an integrated healthcare delivery system. Cases were persons diagnosed with NHL between 1980 and 2011 at age 25 years or older; eight control subjects were matched to each case on age, sex, and length of enrollment. Information on previous TCA use was ascertained from automated pharmacy data. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) for NHL, overall and for common subtypes, for various patterns of TCA use.

We identified 2768 cases and 22,127 matched control subjects. We did not observe an appreciably increased risk of NHL among TCA ever-users compared to non-users (OR, 1.1; 95% CI, 1.0-1.2). Overall risk of NHL was associated to at most a small degree with longer-term use (OR, 1.2; 95% CI, 1.0-1.4; ≥10 prescriptions), high-dose use (OR, 1.1; 95% CI, 0.8-1.5; ≥50 mg), or non-recent use (OR, 1.0; 95% CI, 0.9 = 1.2; >5 years previously). TCA use was not associated with NHL subtypes, except chronic lymphocytic leukemia/small lymphocytic lymphoma (OR, 1.5; 95% CI, 1.1-2.0; longer-term use).

We found little evidence that the use of TCAs increases the risk of NHL overall or for specific common subtypes of NHL.