[Tracing trace elements in mental functions].

Trace elements are found in the living organism in small (trace) amounts and are mainly essential for living functions. Essential trace elements are in humans the chromium (Cr), cobalt (Co), copper (Cu), fluorine (F), iodine (I), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), zinc (Zn), and questionably the boron (B) and vanadium (V). According to the biopsychosocial concept, mental functions have biological underpinnings, therefore the impairment of certain neurochemical processes due to shortage of trace elements may have mental consequences. Scientific investigations indicate the putative role of trace element deficiency in psychiatric disorders such in depression (Zn, Cr, Se, Fe, Co, I), premenstrual dysphoria (Cr), schizophrenia (Zn, Se), cognitive deterioration/de-mentia (B, Zn, Fe, Mn, Co, V), mental retardation (I, Mo, Cu), binge-eating (Cr), autism (Zn, Mn, Cu, Co) and attention deficit hyperactivity disorder (Fe). At the same time, the excess quantity (chronic exposure, genetic error) of certain trace elements (Cu, Mn, Co, Cr, Fe, V) can also lead to mental disturbances (depression, anxiety, psychosis, cognitive dysfunction, insomnia). Lithium (Li), being efficacious in the treatment of bipolar mood disorder, is not declared officially as a trace element. Due to nutrition (drinking water, food) the serum Li level is about a thousand times less than that used in therapy. However, Li level in the red cells is lower as the membrane sodium-Li countertransport results in a Li efflux. Nevertheless, the possibility that Li is a trace element has emerged as studies indicate its potential efficacy in such a low concentration, since certain geographic regions show an inverse correlation between the Li level of drinking water and the suicide rate in that area.