It is difficult to differentiate whether neuropsychiatric symptoms are caused by systemic lupus erythematosus (SLE) or psychiatric background, coexisting disorders or drug-induced side effects. The aim of this paper is to present two cases of psychotic symptoms (bipolar and paranoid disorder) induced by chloroquine.

Case 1: Severe depressive episode with psychotic features appeared in the context of third SLE exacerbation and chloroquine treatment. Hydroxychloroquine was used instead and symptoms resolved. Later, manic episode (with psychotic features) emerged several days after chloroquine was prescribed for concomitant arthritis. Since that time, chloroquine has been withdrawn. Currently the patient is undergoing treatment with hydroxychloroquine and psychiatric drugs with good response.

Case 2: The second patient started to suffer from headaches and being lightheaded three days after chloroquine administration and within next few days feeling of derealization and poorly defining persecutory delusions accompanied by strong anxiety with occasional visual illusions occurred with clear consciousness. After eighteen days chloroquine was withdrawn and after two days all the symptoms resolved.

Clinicians should be vigilant for possible psychiatric disorder when using chloroquine in patients with SLE. Such cases are probably rare and may include both paranoid and bipolar spectrum disorders. Studies on interactions of chloroquine with brain neurotransmitter systems are needed. Hydroxychloroquine may represent lower risk considering psychiatric complications. Mechanism of the difference is currently not known.