The paradox of modern clozapine psychiatry

Clozapine remains the most effective treatment for treatment-resistant schizophrenia and one of the few psychiatric medications consistently associated with reduced suicidal behaviour. ^{Reference Kane, Honigfeld, Singer and Meltzer1–Reference Leucht, Cipriani, Spineli, Mavridis, Orey and Richter3} Nevertheless, its use remains markedly limited across many healthcare systems despite decades of evidence supporting its unique efficacy. ^{Reference Farooq, Choudry, Cohen, Naeem and Ayub4}

The reasons are multifactorial and extend well beyond haematological risk. Clinician- and service-level barriers include reluctance or therapeutic inertia in initiating a comparatively demanding treatment, concern about adverse effects and monitoring and persistence with non-clozapine strategies, including high-dose treatment and antipsychotic polypharmacy, even after treatment resistance is established. ^{Reference Farooq, Choudry, Cohen, Naeem and Ayub4–Reference Howes, Vergunst, Gee, McGuire, Kapur and Taylor6} Clinician assumptions about patient reluctance also require qualification: in a study of clozapine-eligible patients, blood testing would not have precluded treatment for 57% whereas admission for initiation, adverse-effect concerns and limited expectations of benefit were more prominent obstacles. ^{Reference Gee, Shergill and Taylor7}

Among these factors, historical reluctance has been strongly shaped by fears surrounding severe adverse drug reactions, particularly agranulocytosis. Following reports of fatal haematological complications during the 1970s, clozapine became associated with an exceptional degree of regulatory caution within psychiatry. Mandatory monitoring systems and restrictive prescribing frameworks reinforced the perception of clozapine as a uniquely hazardous medication.

However, contemporary psychiatry now operates within a substantially different clinical and pharmacovigilance environment. Routine haematological monitoring facilitates early detection of clinically relevant neutropenia and has substantially reduced the lethality associated with clozapine-induced agranulocytosis. Advances in pharmacokinetics, therapeutic drug monitoring and individualised prescribing strategies have further improved clozapine safety. ^{Reference de Leon, Ruan, Schoretsanitis and De Las Cuevas8} Recent evidence also challenges the assumption that every neutropenic episode observed during clozapine treatment is necessarily caused by clozapine. Oloyede and colleagues reported that rechallenge after mandated cessation for suspected clozapine-induced neutropenia can be successful in carefully selected patients. ^{Reference Oloyede, Dzahini, MacCabe, Casetta, Oliver and Shergill9} More directly, Wallman and colleagues reviewed 96 episodes of severe neutropenia leading to clozapine cessation and judged only 9 to be definitely and 11 probably caused by clozapine; in almost 80% of cases, clozapine was not a clear cause. ^{Reference Wallman, Govind, Casetta, Whiskey, Gandhi and Jewell10} These findings do not diminish the seriousness of true clozapine-induced agranulocytosis, but they suggest that threshold-based attribution can substantially overestimate clozapine causality. In 2025, the U.S. Food and Drug Administration removed the clozapine risk evaluation and mitigation strategy programme after concluding that the programme itself was no longer necessary to ensure that the benefits of clozapine outweighed the risk of severe neutropenia. ¹¹

At the same time, schizophrenia spectrum disorders remain associated with profound premature mortality, including markedly elevated suicide risk and substantially reduced life expectancy. ^{Reference Hjorthøj, Stürup, McGrath and Nordentoft12} Clozapine therefore presents psychiatry with an important but uncomfortable question: does contemporary psychiatric culture sometimes evaluate treatment- and illness-related mortality through psychologically asymmetrical frameworks?

Rare but emotionally salient adverse reactions may disproportionately shape clinical decision-making, ^{Reference Slovic13} whereas harmful outcomes resulting from inaction are often perceived as less ethically troubling than comparable harms resulting from intervention. In psychiatry, where severe mental illness itself may carry substantial mortality risk, this asymmetry may become particularly relevant.

This editorial does not argue for indiscriminate expansion of clozapine prescribing, nor does it minimise the medication’s potentially severe adverse effects. Rather, it examines whether modern psychiatry may still partly conceptualise clozapine through historically inherited models of risk perception that insufficiently incorporate the lethality of severe suicidality itself.

The asymmetry of psychiatric risk perception

Risk perception in medicine is shaped not only by epidemiological probability, but also by psychological and ethical factors that influence how different forms of harm are interpreted within clinical practice. ^{Reference Slovic13} In psychiatry, this dynamic may become particularly relevant when comparing treatment-attributable mortality with mortality associated with severe mental illness itself.

Deaths potentially related to pharmacological intervention often generate intense professional concern, regulatory scrutiny and medico-legal anxiety. By contrast, deaths associated with the course of severe psychiatric illness – particularly suicide – may become comparatively normalised within routine clinical experience. Iatrogenic harm is directly linked to therapeutic action and may therefore be experienced not only as clinical failure, but also as personal and ethical responsibility.

In the case of clozapine, this asymmetry may be especially important. Rare but catastrophic adverse effects such as agranulocytosis historically became highly visible within psychiatric culture because they represented dramatic examples of treatment-attributable harm. Suicide risk, although epidemiologically far more frequent in schizophrenia spectrum disorders, may exert less influence on emotional risk perception precisely because it remains embedded within the expected background mortality of severe mental illness. ^{Reference Hjorthøj, Stürup, McGrath and Nordentoft12}

Behavioural decision-making research has consistently shown that harmful outcomes resulting from action are often perceived as less acceptable than comparable harms resulting from inaction, even when objective risk differs little. ^{Reference Ritov and Baron14} Such dynamics may subtly influence psychiatric prescribing culture. Clinicians may understandably fear causing a severe adverse drug reaction more than failing to prevent a suicide that emerges within the natural course of illness.

This does not imply that clozapine-related risks should be minimised. Clozapine remains associated with potentially severe and sometimes life-threatening adverse reactions requiring careful monitoring and individualised prescribing strategies. ^{Reference de Leon, Ruan, Schoretsanitis and De Las Cuevas8} The relevant issue, however, is whether psychiatry may sometimes evaluate competing forms of mortality through psychologically asymmetrical frameworks that insufficiently incorporate the lethality of severe suicidality itself.

The broader implications extend beyond clozapine alone. Severe mental disorders remain associated with profound premature mortality and substantially reduced life expectancy. ^{Reference Hjorthøj, Stürup, McGrath and Nordentoft12} Under such conditions, psychiatric decision-making rarely involves choosing between risk and safety, but rather navigating competing risks under conditions of uncertainty.

Clozapine therefore represents more than a psychopharmacological treatment. It also provides a revealing case study in how psychiatry conceptualises mortality, responsibility and therapeutic risk when both intervention and non-intervention may carry potentially lethal consequences.

Clozapine and suicide prevention

Among psychopharmacological agents, clozapine occupies a uniquely complex position. It is simultaneously one of the most effective treatments in psychiatry and one of the medications most historically associated with regulatory caution and prescribing reluctance. Yet clozapine may also possess another distinctive characteristic that remains comparatively underemphasised within contemporary psychiatric practice: a relatively specific and unusually consistent association with reduced suicidal behaviour. ^{Reference Meltzer, Alphs, Green, Altamura, Anand and Bertoldi2}

The strongest prospective evidence supporting this effect emerged from the International Suicide Prevention Trial (InterSePT), which demonstrated that clozapine was superior to olanzapine in reducing suicide attempts and interventions aimed at preventing suicidal behaviour in high-risk patients with schizophrenia and schizoaffective disorder. ^{Reference Meltzer, Alphs, Green, Altamura, Anand and Bertoldi2} Subsequent observational and population-based studies have generally reinforced the association between clozapine treatment, lower suicide rates and reduced all-cause mortality compared with other antipsychotic treatments. ^{Reference Hjorthøj, Stürup, McGrath and Nordentoft12,Reference Turecki, Brent, Gunnell, O’Connor, Oquendo and Pirkis15}

The mechanisms underlying these effects remain incompletely understood. Proposed explanations include superior efficacy in treatment-resistant psychosis, reductions in impulsivity and affective dysregulation, improved subjective well-being and broader reductions in psychosocial destabilisation. Importantly, suicide in schizophrenia-spectrum disorders is not merely a consequence of psychotic symptoms themselves, but a multidimensional phenomenon shaped by affective suffering, hopelessness, trauma exposure, substance use and the cumulative burden of severe mental illness. ^{Reference Turecki, Brent, Gunnell, O’Connor, Oquendo and Pirkis15}

Despite this, clozapine’s anti-suicidal potential often remains secondary within broader psychiatric risk–benefit discussions, where the medication continues to be viewed primarily through the lens of adverse-event management. The issue, therefore, is not whether clozapine carries risk, but whether contemporary psychiatric culture fully incorporates the lethality of severe suicidality into the way those risks are comparatively interpreted.

This editorial does not advocate expansion of clozapine prescribing beyond evidence-based frameworks, nor does it minimise the importance of careful pharmacovigilance. Rather, it argues that psychiatric risk–benefit models may benefit from more explicitly integrating the mortality associated with severe mental illness itself when evaluating one of the few psychiatric treatments consistently linked to reduced suicidal behaviour.