Many patients with panic disorder-agoraphobia (PD) are treated with antidepressants. Many patients discontinue treatment because of side effects. The side effects responsible for poor medication adherence are jitteriness, weight gain, sexual impairment and anticholinergic symptoms. Some patients discontinued medication due to pharmacophobia.

The present study examined the relationship between the long-term treatment response, occurrence of side effects and noncompliance. A total of 326 PD patients were treated with antidepressants and followed for three years. The medications used were imipramine n = 127, 39%; clomipramine n = 93, 28.5%; paroxetine n = 76, 23.3%; or "other antidepressants" n = 30, 9.2%. The Structured Clinical Interview for Diagnosis (SCID), the Panic Disorder/Agoraphobia Interview (PDI) and the Longitudinal Interview Follow up Examination (Life-up) were used to evaluate all patients.

During the three-year follow-up period, 179 patients (54.9%) stopped pharmacological treatment. Forty-eight patients (26.8%) were not traceable or refused to be interviewed. Among the remaining patients, 66 (20.2%) patients felt psychiatric help was unnecessary because of PD remission. Interestingly, patients who discontinued medication due to remission had fewer relapses than patients who remained in the study. Other reasons for discontinuing medication were ineffectiveness of the treatment (n = 39, 18.4%), side effects (n = 19, 10.6%) and personal reasons (n = 13, 7.3%). The most common side effects were nausea, anticholinergic symptoms, jitteriness, tremor, and weight gain. In general, patients receiving tricyclic antidepressants (TCAs) reported more side effects than did patients treated with selective serotonin reuptake inhibitors (SSRIs). Personal reasons included moving or changing doctors.

Patients who interrupted pharmacological treatment because of symptom remission remained in the study longer than did patients who stopped medication because of lack of efficacy. Severity of PD and agoraphobia and the length of illness were significantly lower in subjects who interrupted the treatment for remission of PD compared to the other groups. Patients who remained on medication and were more compliant with the medication regimen had more severe agoraphobia, longer duration of illness, more dependent and depressive traits, and late-onset remission.

Dr. Perugi believes that several factors may be responsible for patient noncompliance. These include side effects, inefficacy of treatment, and symptom remission. Dr. Perugi concludes that PD patients with more severe and long lasting symptoms may have better compliance with long-term antidepressant treatment.

(abstract Session 31 No. 90)