Having ruled out (as far as practically possible) underlying medical conditions and confirmed the probable diagnosis of Illness Anxiety Disorder, attention should turn to treatment options.
Few pharmacological trials for the treatment of Illness Anxiety Disorder have been conducted. Some evidence, mostly from open-label studies (meaning studies where all patients received the active medication without some sort of control group), supports the use of SSRIs in Hypochondriasis. Where SSRIs are used, we advise using dosing regimens akin to those found to be effective for OCD (see OCD chapter). This recommendation is based on clinical similarities between these two conditions.
In a double-blind study conducted in Hypochondriasis, 16-week treatment with the SSRI paroxetine was superior to placebo for those who completed the trial but failed to demonstrate efficacy for those who discontinued early. The dosing regimen for paroxetine was 10mg/day in week 1, 20mg/day in week 2, with subsequent dosing increments of up to 20mg/day for each week of treatment, to a maximum of 60mg/day. Similar positive results were found in another double-blind placebo-controlled study using fluoxetine. The dosing regimen for fluoxetine was 20mg/day increasing by 20mg/ day every two weeks as needed and tolerated, up to a maximum of 80mg/day.
When patients with Hypochondriasis were treated with 12-week SSRI (fluoxetine/fluvoxamine) and followed up later
(mean ~9 years later), 40% still met criteria for Hypochondriasis. Interval treatment with an SSRI for at least one month was associated with greater rates of remission at follow-up (80% versus 40% remission rates).