LSD

Hypertension, coronary artery disease, arrhythmias, or other significant cardiovascular conditions. Effects are moderate and self-limiting in healthy subjects. No QTc prolongation documented.

Active epilepsy or seizure disorder of any etiology. The seizure risk documented in LSD+lithium interactions indicates potential for seizure provocation in neurologically vulnerable individuals.

Personal or family history of schizophrenia, schizoaffective disorder, or other psychotic disorders. Standard exclusion criterion across all modern LSD clinical trials. Risk applies to both personal history and first-degree family history.

Bipolar disorder type I is an absolute contraindication. Bipolar II is a relative contraindication requiring careful individual risk-benefit assessment. Standard exclusion criterion in clinical trials.

Pregnancy and breastfeeding. No human reproductive toxicity data have been published. Theoretical uterotonic risk from ergoline class pharmacology.

Current lithium therapy at any dose, including subtherapeutic levels. Seizures have been documented even at subtherapeutic lithium serum concentrations. No safe dose combination has been identified.

Current or recent use of monoamine oxidase inhibitors (MAOIs), including irreversible (phenelzine, tranylcypromine) and reversible (moclobemide) forms. Washout period of at least 2 weeks for irreversible MAOIs recommended before LSD administration.