Hypomania Secondary to a Change in Altitude in an Adolescent Male

Abstract

Introduction Altitude-associated changes in renal and endocrine function and lithium pharmacokinetics have not been applied to persons diagnosed with bipolar disorder. Development of a mood or affective syndrome secondary to a change in altitude has been a topic of some debate. Research is limited. This may represent an emerging area of concern for clinicians. Psychiatric and neurologic changes associated with altitude have been published. The potential for altitudemediated mood changes was evaluated both naturalistically and experimentally. Mood symptoms were evaluated as a function of rate of assent, climber experience, elevation, and duration of exposure. Adverse mood symptoms were found to be affected by altitude changes (1, 2). Acute changes secondary to altitude included new-onset anxiety disorders (3) and, rarely, cerebral edema (4). Additional altitude-associated neurological changes reported in the literature include headache, fatigue, and/or ataxia. Experimentally, researchers subjected experienced climbers to high-altitude conditions via a hypobaric chamber. They found a significant negative relationship with a personality measure for emotional stability (5). The designation of low versus high altitude may represent a valid point for discussion. Designations varied with the research design. When investigating the pharmacokinetics of lithium, one set of researchers defined low altitude as 600 meters, high altitude as 4,360 meters (6). High altitude for other researchers ranged from 3,000 to 8,848 meters (5). Changes in mood and cognitive and motor functions were reported with elevations above 3,000 meters (2). The treatment center in this Case Report was located at 1,088 meters. In persons diagnosed with bipolar disorder, changes in lithium pharmacokinetics may offer an alternate explanation for mood changes secondary to high-altitude exposure that may result in a number of physiological changes. One of these changes is an increase in circulating red blood cells (RBC) (7). This is an important consideration with lithium use. Intraand extra-cellular transport occurs via erythrocytes, where lithium is tightly bound (6). The question of whether mild-to-moderate cerebral hypoxia may constitute a hypoxic affective syndrome and contribute to physical illness was raised by some researchers. One theory focused on biogenic amine production: if hypoxia was a function of altitude, then a neurochemical process formed the basis for behavioral and physical changes (8). Changes in lithium pharmacokinetics were studied in healthy volunteers at high and low altitudes. Those at low altitude transitioned to high altitude. Findings were compared with a second group of volunteers exposed to long-term high altitude. Both the acuteand chronic-exposure groups demonstrated increases in hematocrit and RBC counts. Researchers concluded altered lithium pharmacokinetics were secondary to changes in altitude and may be important clinically (6). We report the first potential case of altitudeassociated hypomania, secondary to a change in lithium pharmacokinetics, in an adolescent patient following a change from a high-altitude residence to a return to low altitude.