Medication Adherence in People with Schizophrenia and the Role of the Mental Health Nurse: A Literature Review

Background to People with Schizophrenia

The World Health Organization (2026) estimates that around 1 in 300 people worldwide, or 27 million people, live with schizophrenia. The condition is associated with substantial disability, stigma and premature death, and the World Health Organization reports that people with schizophrenia die nine years earlier than the general population. Access to care remains limited, with only 29% of people with psychosis receiving specialist mental health care.

Antipsychotic medication remains the main pharmacological treatment. In England, NICE guidance on psychosis and schizophrenia in adults (NICE, 2014) asks services to work in partnership with people with schizophrenia and their carers and to offer care in an atmosphere of hope and optimism. Guidance based on CG178 also states that the choice of antipsychotic should be made jointly by the prescriber and the service user, that the side effects each person is most willing to tolerate should be discussed and that long-acting injectable preparations can be considered where a person prefers them.

Adherence is the extent to which a person’s medication-taking matches the agreed treatment plan. Older terms such as compliance imply that the person should simply follow instructions, whereas concordance describes an agreement reached through open discussion between the person and the clinician, in which the person’s beliefs and preferences are respected. The shift towards concordance reflects wider moves towards recovery-oriented and person-centred mental health care.

Nonadherence can be intentional, for example when someone decides to stop medication because of side effects or because they do not believe they are unwell, or unintentional, for example when someone forgets doses or finds the regimen confusing (Haddad et al., 2014). These different forms require different nursing responses, which is why understanding the reasons behind nonadherence matters as much as measuring its frequency.

Search Strategy and Methods

Evidence on people with schizophrenia for this example was identified through targeted searches of openly accessible bibliographic records, publisher websites and the reference lists of key reviews. Search terms combined keywords for the population (“schizophrenia”, “psychosis”), the treatment (“antipsychotic”, “maintenance treatment”) and the outcome or intervention (“adherence”, “nonadherence”, “concordance”, “adherence therapy”, “relapse”), joined with the Boolean operators AND and OR. A full narrative review for assessment would run the same strategy in CINAHL, PubMed/MEDLINE, the Cochrane Library and Embase and report the number of records screened in a PRISMA flow diagram.

Sources were eligible if they addressed people with schizophrenia or related psychotic disorders aged 18 years or over and reported on antipsychotic maintenance treatment, the prevalence or causes of nonadherence, or interventions to support adherence that could be delivered or coordinated by nurses. Cochrane and other systematic reviews, randomised controlled trials, national guidance and international data were prioritised. Studies focused only on first-episode psychosis in adolescents, or on specific drug comparisons without adherence outcomes, were excluded.

Seven sources about people with schizophrenia published between 2002 and 2026 were included: a Cochrane review, three further reviews, a multicentre randomised trial, a national guideline and an international fact sheet (Table 1). One older review was retained because it remains the most widely cited synthesis of nonadherence rates. The quality of each source was appraised using the Critical Appraisal Skills Programme (CASP) checklist appropriate to its design, and findings were synthesised narratively and grouped into themes.

Key Findings on People with Schizophrenia

Three themes were identified: the benefits and burdens of antipsychotic maintenance treatment, the extent and causes of nonadherence, and the effectiveness of adherence interventions and concordance-based nursing. Table 1 summarises the included sources, and Figure 1 shows the main outcomes of antipsychotic maintenance treatment compared with placebo.

Author, year	Design	Setting and sample	Key finding
Lacro et al. (2002)	Comprehensive literature review	39 articles on medication nonadherence in schizophrenia	Mean nonadherence 41.2% (49.5% in most rigorous studies); poor insight, negative attitudes and weak alliance key predictors.
Gray et al. (2006)	Multicentre randomised controlled trial	409 people with schizophrenia and recent instability; European mental health services	Eight sessions of adherence therapy were no more effective than health education for quality of life at 52 weeks.
Leucht et al. (2012)	Cochrane systematic review	65 RCTs, 6,493 participants	Relapse at 7–12 months 27% with antipsychotics vs 64% with placebo; more movement disorders and weight gain.
NICE (2014)	National clinical guideline (CG178)	Adults with psychosis and schizophrenia in England	Partnership working; joint choice of antipsychotic; discussion of side effects; long-acting injections considered.
Haddad et al. (2014)	Narrative review	Literature on antipsychotic nonadherence	Nonadherence affects over a third each year; tailored, combined psychosocial approaches and shared decisions recommended.
Gray et al. (2016)	Systematic review and meta-analysis	6 RCTs, 725 participants	Adherence therapy reduced symptoms (SMD −0.56) but did not significantly change adherence or attitudes.
World Health Organization (2026)	International fact sheet	Global data	Around 1 in 300 people live with schizophrenia; only 29% of people with psychosis receive specialist care.

Theme 1: Why Antipsychotic Maintenance Matters for People with Schizophrenia

The strongest evidence on the value of continued treatment comes from a Cochrane review by Leucht et al. (2012), which included 65 randomised trials with 6,493 participants. Between seven and twelve months, 27% of people who continued antipsychotic medication relapsed, compared with 64% of those switched to placebo (risk ratio 0.40), giving a number needed to treat of three. Fewer people taking antipsychotics were readmitted to hospital (10% compared with 26%), and quality of life was better in the small number of trials that measured it.

The same review also shows the costs of treatment. Movement disorders were more common with antipsychotic medication (16% compared with 9%), as were sedation (13% compared with 9%) and weight gain (10% compared with 6%). These side effects are not trivial. They affect appearance, physical health and self-esteem, and they are among the reasons people give for stopping medication. Nurses therefore need to hold two messages at once: maintenance treatment substantially reduces relapse, but it has burdens that must be acknowledged and actively managed.

There are limits to how far these findings can be generalised. Most trials compared continuing medication with abrupt withdrawal to placebo, which may exaggerate relapse in the placebo group, and few trials lasted beyond a year. The review cannot show which individuals might safely reduce or stop medication. This uncertainty supports open, shared discussion rather than a single message that everyone must remain on medication indefinitely.

Theme 2: The Extent and Causes of Nonadherence

In a comprehensive review of 39 articles, Lacro et al. (2002) found a mean nonadherence rate of 41.2% in studies meeting strict criteria, rising to 49.5% in the most rigorous studies. The factors most consistently associated with nonadherence were poor insight, negative attitudes towards medication, previous nonadherence, substance misuse, shorter illness duration, inadequate discharge planning or aftercare and a poorer therapeutic alliance. Notably, side-effect severity and route of administration were not consistent predictors.

Haddad et al. (2014) reached similar conclusions more than a decade later, reporting that nonadherence affects more than one third of people with schizophrenia each year and is often hidden and underestimated by clinicians. They described contributing factors linked to the person, the illness, the medication, the clinician and the service, including stigma, social isolation, depression and cognitive impairment. Nonadherence increased the risk of relapse, readmission and self-harm and reduced quality of life. They also noted that there is no gold-standard way to measure adherence.

Two points stand out for nursing. First, several of the strongest predictors, such as the therapeutic alliance and the quality of discharge planning, are modifiable features of care rather than fixed characteristics of the person. Second, the finding that clinicians underestimate nonadherence suggests that routine, non-judgemental conversations about medication are needed, rather than assumptions based on how well someone appears to be. Asking directly, and accepting honest answers without criticism, may reveal more than relying on clinical impression.

Theme 3: Adherence Therapy, Concordance and Nursing Interventions

Adherence therapy is a brief, structured intervention, usually of around eight sessions, that uses motivational interviewing and cognitive behavioural techniques to explore a person’s beliefs about medication. In a European multicentre randomised trial, Gray et al. (2006) randomised 409 people and compared eight sessions of adherence therapy with eight sessions of health education for people with schizophrenia who had recently been clinically unstable. After 52 weeks, adherence therapy was no more effective than health education in improving quality of life.

A later meta-analysis by Gray et al. (2016) pooled six randomised trials involving 725 participants. Adherence therapy reduced psychiatric symptoms compared with usual treatment (standardised mean difference −0.56) over follow-up of less than one year, but it had no significant effect on adherence behaviour or on attitudes to medication. Heterogeneity was very high (I² 86%), and the trials were few and varied in quality. The finding that symptoms improved without measurable change in adherence is puzzling and suggests that general therapeutic engagement may account for some of the benefit.

Haddad et al. (2014) concluded that combined psychosocial approaches appear more effective than single-component interventions and that support should be tailored to the individual. Practical strategies included shared decision-making, regular checks on adherence, simplifying regimens, managing side effects and building a strong therapeutic alliance. Long-acting injectable antipsychotic medication and electronic reminders, such as text messages and smart pill containers, may help some people, while financial incentives raise ethical concerns and their role remains unclear. These recommendations are consistent with the concordance-based approach set out in NICE guidance.

Discussion

This review shows that antipsychotic maintenance treatment substantially reduces relapse and readmission for people with schizophrenia, that nonadherence is common and multi-causal, and that specific adherence interventions have produced mixed results. The evidence on the benefits of maintenance treatment is strong, but the evidence on how best to support adherence is weaker and more uncertain.

A central tension lies between the strength of the case for continued medication and the respect owed to individual choice. Leucht et al. (2012) provides compelling population-level evidence, yet side effects are real, and some people decide that the burdens outweigh the benefits for them. A concordance approach does not abandon the evidence; it shares it honestly, explores the person’s priorities and seeks an agreement that the person can sustain. This is more consistent with recovery-oriented care than persuasion alone.

The disappointing results for adherence therapy also deserve reflection. Gray et al. (2006) found no effect in routine settings, and Gray et al. (2016) found improvements in symptoms but not in adherence itself. One explanation is that adherence is shaped by many factors, including insight, substance use, stigma and service continuity, that a short course of sessions cannot address alone. Another is that the measurement of adherence is unreliable, as Haddad et al. (2014) noted, making true effects hard to detect.

These findings have implications for the role of mental health nurses. Rather than relying on a single packaged intervention, nurses may be most effective when concordance-based conversations are woven into every contact, alongside practical help with side effects, regimens, physical health and social needs. Continuity of care for people with schizophrenia, particularly around discharge, appears important, given that inadequate discharge planning and a weak therapeutic alliance were consistently linked to nonadherence.

The role of long-acting injectable medication illustrates these tensions. For some people with schizophrenia, an injection every few weeks removes the burden of daily tablets and makes missed doses visible, allowing nurses to follow up promptly. NICE (2014) supports considering long-acting preparations where a person prefers them. However, injections can feel coercive when they are linked to community treatment orders or offered without genuine choice, and they do not remove side effects. Nurses who administer injections are therefore in a key position to keep the conversation about treatment open, to review side effects and physical health at each visit and to ensure that consent remains meaningful.

This review has limitations. It relied on openly accessible, English-language sources, did not involve independent double screening and included one older review alongside more recent evidence. Many included studies came from high-income countries, and few captured service users’ own accounts of medication decisions. Future research should test multi-component, nurse-delivered concordance interventions with reliable adherence measures, include longer follow-up and involve service users in defining meaningful outcomes.

Implications of People with Schizophrenia Evidence for Practice

For mental health nurses, the evidence supports routine, non-judgemental discussion of medication at every contact, using open questions to explore beliefs, side effects and practical barriers. Nurses should share balanced information about the benefits of maintenance treatment and its burdens, support joint decisions about the choice of antipsychotic and route of administration, monitor and act on side effects and physical health, and pay close attention to discharge planning and continuity of care. Families and carers should be involved where the person agrees.

Concordance depends on a trusting therapeutic relationship, and many service users have experienced coercive treatment or earlier adversity, so the principles of trauma-informed care are directly relevant to medication discussions. Nurses should also recognise that substance misuse is a strong predictor of nonadherence and may require integrated care for dual diagnosis, and that relapse and nonadherence increase the risk of self-harm, which should be assessed and addressed.

Conclusion

This narrative review found that antipsychotic maintenance treatment markedly reduces relapse and readmission for people with schizophrenia, but that nonadherence affects a large proportion and arises from personal, clinical and service factors. Single adherence interventions have produced mixed results, whereas combined, individually tailored approaches based on shared decision-making appear more promising.

Mental health nurses can best support people with schizophrenia by building trusting relationships, discussing medication openly and honestly, managing side effects and ensuring continuity of care. Treating medication as a shared decision rather than an instruction is likely to be both more ethical and more effective.

References

Gray, R., Bressington, D., Ivanecka, A., Hardy, S., Jones, M., Schulz, M., von Bormann, S., White, J., Anderson, K. H., & Chien, W. T. (2016). Is adherence therapy an effective adjunct treatment for patients with schizophrenia spectrum disorders? A systematic review and meta-analysis. BMC Psychiatry, 16, 90. https://doi.org/10.1186/s12888-016-0801-1

Gray, R., Leese, M., Bindman, J., Becker, T., Burti, L., David, A., Gournay, K., Kikkert, M., Koeter, M., Puschner, B., Schene, A., Thornicroft, G., & Tansella, M. (2006). Adherence therapy for people with schizophrenia: European multicentre randomised controlled trial. British Journal of Psychiatry, 189(6), 508–514. https://doi.org/10.1192/bjp.bp.105.019489

Haddad, P. M., Brain, C., & Scott, J. (2014). Nonadherence with antipsychotic medication in schizophrenia: Challenges and management strategies. Patient Related Outcome Measures, 5, 43–62. https://doi.org/10.2147/PROM.S42735

Lacro, J. P., Dunn, L. B., Dolder, C. R., Leckband, S. G., & Jeste, D. V. (2002). Prevalence of and risk factors for medication nonadherence in patients with schizophrenia: A comprehensive review of recent literature. Journal of Clinical Psychiatry, 63(10), 892–909. https://doi.org/10.4088/JCP.v63n1007

Leucht, S., Tardy, M., Komossa, K., Heres, S., Kissling, W., & Davis, J. M. (2012). Maintenance treatment with antipsychotic drugs for schizophrenia. Cochrane Database of Systematic Reviews, (5), CD008016. https://doi.org/10.1002/14651858.CD008016.pub2

National Institute for Health and Care Excellence. (2014). Psychosis and schizophrenia in adults: Prevention and management (Clinical guideline CG178). https://www.nice.org.uk/guidance/cg178

World Health Organization. (2026). Schizophrenia [Fact sheet]. https://www.who.int/news-room/fact-sheets/detail/schizophrenia