Iron overload among a psychiatric outpatient population

Iron overload has been suggested to be an unrecognized cause of psychiatric morbidity. This study sought to estimate the prevalence of iron overload in a large outpatient psychiatric clinic.

A retrospective review of screening blood chemistries was conducted on 661 active outpatients at a large, university outpatient psychiatric clinic to identify elevated iron status results (plasma iron, percentage of iron saturation) suggestive of iron overload. Patients with positive profiles were asked to undergo a subsequent blood chemistry to confirm positive results (plasma iron, percentage of iron saturation, plus plasma ferritin). Patients with positive repeated iron chemistry results were considered likely candidates for iron overload.

Twenty-one patients (3.2%) were identified as meeting one of the criteria suggestive of iron overload on initial screening reports. Thirty-one percent of those who underwent subsequent, confirmatory testing (5/16) continued to meet one of the criteria. On the basis of these results, we estimated a 1% (3.2 x 0.31) prevalence rate of likely candidates for iron overload. A review of these patients' charts indicated that they carried an unexpectedly high rate of bipolar affective disorder (80%) as a diagnosis and were, without exception, atypical in that they were resistant to conventional psychiatric treatment and lacked a family history for this disorder. The prevalence of positive iron overload profiles on a routine blood chemistry was similar to the prevalence of positive thyroid abnormalities based on TSH results in this population.

Blood chemistry profiles suggestive of iron overload may be associated with a small portion of treatment-resistant psychiatric patients. Routine screening for iron abnormalities, especially in treatment-resistant patients, should be considered. Further studies are required to determine the causal association, if any, between iron excess and primary psychiatric illnesses.