Clinical correlates of low serum carnitine levels in hospitalized psychiatric patients.

OBJECTIVE We sought to evaluate clinical correlates of low serum carnitine levels in hospitalized psychiatric patients. METHODS We retrospectively reviewed the charts of 40 psychiatric inpatients identified to have low serum carnitine levels. RESULTS Cognitive impairment was present in 38 (95%) cases, frequently accompanied by imbalance, agitation and extrapyramidal symptoms. Valproate therapy was encountered in 28 (70%) patients. The dosage of valproate negatively correlated with total and free carnitine levels (P = 0.003 and 0.0136). Polypharmacy also affected carnitine levels, indicating additional modulatory effects on carnitine metabolism. We encountered a disproportionately high prevalence of mental retardation and dementia in association with hypocarnitinemia. CONCLUSION We hypothesize that in the context of mental illness hypocarnitinemia may be associated with metabolic encephalopathy and cognitive impairment. As carnitine deficiency is a potentially treatable condition further studies are warranted.