Objective: Psychosis-associated creatine kinase (CK)-emia (PACK) is a common and pronounced laboratory abnormality that accompanies adult psychotic conditions. Adult PACK is a relatively consistent individual trait. The authors investigated whether psychotic adolescents also present with such PACK characteristics.
Method: Participants were 127 newly admitted, drug-free, psychotic Israeli adolescents. Measures were baseline psychotic severity, serum creatine kinase (CK0), lactate dehydrogenase (LDH0), glutamate oxaloacetate transaminase (SGOT0), white blood cell count (WBC0), urine myoglobulin, and the repeated CK (RepCK) measurements taken during recurrent psychotic episodes.
Results: Schizophrenia was the prevalent diagnosis (53%). CK0 levels did not correlate with the severity of the psychotic symptoms. Twenty-one percent of patients had a CK0 level >1,000 IU/L. CK0 and RepCK levels were higher in males than in females (p < or = .001) and in Jewish Sephardi patients than in Ashkenazi patients (p < .007). There was no difference by diagnosis. Logarithmic (Ln) CK0 correlated with RepCK, SGOT0, LDH0, and WBC0 (r = +0.32-0.74, p < .001) but correlated inversely with serum cholesterol0 (r = -0.36, p = .002) in males. Even prominent PACK was not associated with myoglobinuria. These findings remained significant among the younger patients (aged <18 years). In males from this subgroup, LnCK0 also correlated with age (p < .007) but not with weight.
Conclusions: In psychotic adolescents, PACK is common, is more prevalent among males, is independent of diagnosis, is influenced by ethnicity, and tends to recur.