Hoarders were significantly older than non-hoarding OCD patients (p < 0.001) (see ). There was a significantly higher proportion of women in the compulsive hoarding group than in the non-hoarding group (p < 0.001). Nine of the 32 compulsive hoarders (28%) and 21 of the 47 non-hoarding OCD patients (45%) had current comorbid major depressive episodes, two compulsive hoarders and five non-hoarding OCD patients had comorbid tic disorders, and two of the non-hoarding OCD patients had compulsive skin-picking. The prevalence of current comorbid major depression was not significantly different between the two groups. Mean pre-treatment Y-BOCS, HDRS, Ham-A, and GAS scores were each nearly identical in the two groups.
Clinical variables of study population before and after treatment (Mean [±SD])
Sixteen patients were able to tolerate 60 mg/day, seven reached a final dose of 50 mg/day, 38 received 40 mg/day, six could tolerate only 30 mg/day, three were on 20 mg/ day, three had doses reduced below 20 mg/day, and six dropped out of the study before their doses were increased beyond 10 mg/day. The most common side effects limiting dose increases were sedation, fatigue, constipation, akathisia, headaches, and sexual side effects. There was no significant difference between groups in dose of paroxetine, but compulsive hoarders had a longer duration of treatment then the non-hoarding OCD group (t = 3.1, df = 63, p = 0.003). Of the 32 compulsive hoarders, 25 (78%) completed treatment, one patient dropped out due to intolerable side effects, one patient was discharged because of hospitalization for heart disease, and five dropped out for unknown reasons and were lost to follow-up. Forty of the 47 non-hoarding OCD patients (85%) completed treatment; one dropped out due to side effects, and five dropped out for unknown reasons and were lost to follow-up. There was no significant difference in study completion rate between groups ().
Both groups improved with treatment, with highly significant changes in Y-BOCS, HDRS, Ham-A, and GAS scores (see ). Changes in symptom severity were nearly identical in the two groups, with no between-groups differences on any outcome measure. There was no significant difference between groups in the proportion of patients who met criteria for response to treatment (). Nine of 32 compulsive hoarders (28%) were classified as responders to treatment, and another seven (22%) were partial responders. In the non-hoarding OCD group, 15 of 47 patients (32%) were responders to paroxetine, and seven (15%) were partial responders. Thus, 50% of compulsive hoarders and 47% of non-hoarding OCD patients had at least a partial response to treatment (>25% decrease in Y-BOCS score). Compulsive hoarders who completed treatment (n = 25) improved slightly more than non-hoarding OCD patients who completed treatment (n = 40) (31% vs. 27% mean decrease on Y-BOCS, between-groups difference not significant). In the subgroup of 25 patients in whom hoarding symptoms were assessed separately from other OCD symptoms, UHSS scores decreased significantly with treatment (F = 24.58, df = 1,16, p < 0.001). UHSS scores decreased from 26.0 ± 3.7 to 19.7 ± 5.8 (24% decline) in the 19 compulsive hoarders rated before and after treatment with the UHSS, and from 4.7 ± 3.5 to 2.5 ± 2.2 (46% decline) in the six non-hoarding OCD patients assessed with the UHSS.
Symptom severity of study population before and after treatment (LOCF) (Mean [±SD])
There were no significant associations between hoarding severity and response to paroxetine treatment in any outcome measure. Across all 79 subjects, pre-treatment hoarding symptom factor scores were not significantly correlated with pre- to post-treatment change in Y-BOCS scores (partial r = 0.06, df = 61, p = 0.32), HDRS scores (partial r = 0.02, df = 61, p = 0.45), Ham-A scores (partial r = 0.07, df = 61, p = 0.29), or GAS scores (partial r = 0.09, df = 61, p = 0.24).