Impact of specific phobia on the risk of onset of mental disorders: A 10-year prospective longitudinal community study of adolescents and young adults

BACKGROUND:
The role of specific phobia as a potentially important psychopathological precursor condition to more severe mental disorders is understudied. We examined the prospective-longitudinal association of early childhood/adolescent phobia with subsequent mental disorders and the proportion of outcome disease incidence attributable to specific phobia simultaneously for a broad range of disorders.
METHODS:
N = 2210 14- to 24-year-old community subjects were followed up for 10 years. DSM-IV-specific phobia as exposure and a broad range of DSM-IV mental disorders as outcomes were assessed with the DSM-IV/M-CIDI. Logistic regressions, adjusting for confounders, were used to estimate the associations of specific phobia with the subsequent onset of outcome disorders.
RESULTS:
Baseline specific phobia predicted the subsequent first onset of anxiety disorders [panic disorder: risk ratio (RR) = 4.38, 95% confidence interval (2.34, 8.21); generalized anxiety disorder: RR = 4.10 (2.19, 7.69); posttraumatic stress disorder: RR = 2.15 (1.13, 4.10); obsessive-compulsive disorder: RR = 3.79 (1.63, 8.82)], affective disorders [major depression: RR = 1.54 (1.16, 2.03); bipolar disorder: RR = 2.20 (1.10, 4.41); dysthymia: RR = 2.75 (1.48, 5.11)], pain disorder: RR = 1.52 (1.14, 2.02), and eating disorders: RR = 2.27 (1.14, 4.51). Population attributable fractions (PAFs; i.e., proportion of outcome disease incidence in the total population attributable to specific phobia) were highest for panic disorder (PAF = 22.9), generalized anxiety disorder (PAF = 32.3), and obsessive-compulsive disorders (PAF = 30.2).
CONCLUSION:
This study provides strong evidence that specific phobia is an early onset disorder predicting the subsequent onset of a range of disorders. Future studies should examine the underlying mechanisms and the potential of using specific phobia as a target for prevention of subsequent psychopathology.