The effects of adherence to antidepressant treatment guidelines on relapse and recurrence of depression.
BACKGROUND
Depression is associated with high rates of relapse and recurrence during a patient's lifetime. Current guidelines regarding treatment recommend 4 to 9 months of continuation antidepressant therapy following remission of acute symptoms to allow more complete resolution of the episode. In this article, we test whether adherence to these recommendations reduces the likelihood of relapse or recurrence in a Medicaid population.


METHODS
We used a Medicaid database covering 1989 through 1994. The sample consists of the 4052 adult patients who filled an antidepressant prescription at the time of an initial diagnosis of depression. These patients were followed up for up to 2 years. Timing and counts of antidepressant prescription claims are used to construct a proxy measure for adherence to guidelines. Relapse or recurrence is defined by evidence of a new episode requiring antidepressant treatment, hospital admission for depression, electroconvulsive therapy, emergency department visit for mental health, or attempted suicide. We used survival analysis to predict relapse or recurrence for each patient and to examine the effect of following treatment guidelines on relapse and recurrence.


RESULTS
Approximately one fourth of the patients had a relapse or recurrence during their follow-up period. Factors that affect relapse and recurrence include comorbidities, race, and guideline adherence. Those who continued therapy with their initial antidepressant were least likely to experience relapse or recurrence; those who discontinued their antidepressant early were most likely to experience relapse or recurrence.


CONCLUSIONS
Adherence to depression treatment guidelines with an antidepressant that is likely to have continuous use by patients reduces the probability of relapse or recurrence.
Melfi
C A
CA
Health Outcomes Evaluation Group, Eli Lilly & Co, Indianapolis, Ind 46285, USA. melfi@lilly.com
Chawla
A J
AJ
Croghan
T W
TW
Hanna
M P
MP
Kennedy
S
S
Sredl
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D000929:Antidepressive Agents, Tricyclic / Q000008:administration & dosage / Q000627:therapeutic use; D003866:Depressive Disorder / Q000188:drug therapy* / Q000517:prevention & control / Q000523:psychology; D011307:Drug Prescriptions / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008484:Medicaid; D008875:Middle Aged; D010349:Patient Compliance; D016016:Proportional Hazards Models; D012107:Research Design; D055502:Secondary Prevention; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D016019:Survival Analysis; D014481:United States
D000928:Antidepressive Agents; D000929:Antidepressive Agents, Tricyclic; D017367:Selective Serotonin Reuptake Inhibitors