Mood Disturbances in a Patient on Statin Therapy: A Case Report

Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are widely used to treat hyperlipidaemia and significantly reduce the risk of cardiovascular events. While generally well tolerated, emerging evidence suggests that statins may, in rare cases, be associated with neuropsychiatric adverse effects, including mood disturbances and behavioural changes. We report the case of a 54-year-old woman with hypertension, but no personal or family history of psychiatric illness, who developed mood and behavioural changes shortly after initiating atorvastatin 10 mg following the detection of dyslipidaemia on routine blood testing. Her regular medications included bisoprolol and amlodipine, which she had been taking for eight years without any prior neuropsychiatric side effects. Symptoms resolved rapidly upon discontinuation and recurred upon rechallenge, prompting cessation and referral for psychological counselling. The Naranjo Adverse Drug Reaction (ADR) Probability Scale yielded a score of 8, indicating a probable relationship between the statin and the mood disturbances. Although uncommon, statin-induced neuropsychiatric symptoms have been documented in genetic studies and pharmacovigilance databases. Proposed mechanisms include reduced central nervous system cholesterol affecting serotonergic neurotransmission and statin-related modulation of cytokine signalling. This case highlights the importance of clinician awareness of potential mood-related side effects of statins, even in patients without prior psychiatric history or those receiving low doses. Early recognition and timely management can minimise patient distress and support safer long-term adherence to lipid-lowering therapy.