The pharmacological interventions available for individuals in the early stages of psychosis are extremely limited. For those at clinical high risk for psychosis, there is no licensed treatment available. For those with first-episode psychosis, all licensed antipsychotic medications act via dopamine D₂ receptors. While treatment with antipsychotics is transformative in some patients, in others, it is ineffective. In addition, these medications can often cause adverse effects which make patients reluctant to take them. This is a particular problem in the early phases of psychosis, when patients are being treated for the first time, as unpleasant experiences may colour their future attitude towards treatment. Recent research has suggested that cannabidiol (CBD), a compound found in the Cannabis sativa plant, may have antipsychotic effects and relatively few adverse effects and could therefore be an ideal treatment for the early phases of psychosis, when minimising adverse effects is a clinical priority. In this review, we consider CBD’s potential as a treatment in the clinical high risk and first-episode stages of psychosis. First, we describe the limitations of existing treatments at these two stages. We then describe what is known of CBD’s mechanisms of action, effectiveness as a treatment for psychosis, adverse effects and acceptability to patients. We discuss how some of the outstanding issues about the utility of CBD in the early phases of psychosis may be resolved through ongoing clinical trials. Finally, we consider the impact of recreational cannabis use and over-the-counter cannabinoids preparations and discuss the potential therapeutic role of other compounds that modulate the endocannabinoid system in psychosis.

可用于精神病早期个体的药物干预极为有限。对于精神病临床高危人群，没有获得许可的治疗方法。对于首发精神病患者，所有获得许可的抗精神病药物均通过多巴胺 D ₂受体起作用。虽然抗精神病药物治疗对某些患者具有变革性，但在另一些患者中却无效。此外，这些药物通常会引起副作用，使患者不愿服用。这是精神病早期阶段的一个特殊问题，当患者第一次接受治疗时，不愉快的经历可能会影响他们未来对治疗的态度。最近的研究表明，大麻二酚 (CBD) 是一种在大麻植物，可能具有抗精神病作用和相对较少的不良反应，因此可能是精神病早期阶段的理想治疗方法，此时将不良反应降至最低是临床优先事项。在这篇综述中，我们考虑了 CBD 作为临床高风险和首发阶段精神病治疗的潜力。首先，我们描述了这两个阶段现有治疗的局限性。然后，我们描述了已知的 CBD 的作用机制、作为精神病治疗的有效性、副作用和患者的可接受性。我们讨论了如何通过正在进行的临床试验来解决有关 CBD 在精神病早期的效用的一些悬而未决的问题。最后，