Many cases of paracetamol poisoning are with suicidal intent, but the association between paracetamol poisoning and subsequent psychiatric disorder is unknown.
Dr Jepsen and colleagues from Denmark
examined poisoning with paracetamol or weak analgesics and subsequent psychiatric disorder.
The study was set in a nested case-control design and based on nationwide Danish registers.
The investigators identified all patients diagnosed with schizophrenia, affective disorder or eating disorder in 1994 to 1998 and matched population controls.
|The risk of schizophrenia increased 4-fold after paracetamol poisoning|
|Alimentary Pharmacology & Therapeutics|
The relative risk of these psychiatric disorders after admission for paracetamol or nonparacetamol poisoning was estimated.
The investigative team adjusted for income, employment and marital status.
The investigators included 12,603 cases with psychiatric disorder, and 1% had a diagnosis of poisoning.
The team reported that only 0.2% of the 252,060 matched population controls had psychiatric disorders.
Compared with those with no diagnoses of weak analgesic poisoning, the risk of schizophrenia increased 4-fold after paracetamol poisoning.
The investigators found that compared to those with no diagnoses of analgesic poisoning, the risk of schizophrenia increased 2-fold after nonparacetamol poisoning.
The risk of affective disorder increased 12-fold after paracetamol poisoning and 3-fold after nonparacetamol poisoning.
The team noted that the risk of eating disorder increased 5-fold after paracetamol poisoning, and 2-fold after nonparacetamol poisoning.
The risk of a diagnosis of psychiatric disorder was very high immediately after poisoning and remained increased for more than 10 years.
Dr Jepsen's team concluded, “Paracetamol poisoning is a strong risk marker for psychiatric disorder, particularly affective disorders.”