Diagnosis and Medication Treatment of Schizophrenia in Adolescents

Abstract

Schizophrenia is a chronic mental health condition that most commonly develops in the third decade of life, but may emerge during adolescence, although in rare cases it can also present in childhood. Pre-adult onset is associated with substantial morbidity, functional impairment, and long-term disability. Accurately diagnosing schizophrenia in youth is particularly challenging, as its symptoms frequently overlap with or are misattributed to other psychiatric or developmental conditions. Conversely, misdiagnosis can also occur when psychotic symptoms are present in patients suffering from other conditions. Establishing an accurate and timely diagnosis is therefore critical to prevent errors in treatment and to optimize prognosis and functional outcomes. Antipsychotic medications are first-line interventions for schizophrenia in youth, with second-generation antipsychotics (SGAs) having the strongest evidence base in this population. Randomized controlled trials and open-label studies support the efficacy of risperidone, aripiprazole, olanzapine, quetiapine, paliperidone, lurasidone, and brexpiprazole in reducing psychotic symptoms in adolescents. In contrast, ziprasidone and asenapine have not demonstrated clear benefit in treatment of schizophrenia in youth. Similar to studies in adults, evidence from pediatric clinical trials suggests that clozapine remains the most effective option for treatment-resistant adolescent schizophrenia, although its use requires close monitoring for hematologic and other adverse effects. While SGAs are generally favored over first-generation antipsychotics (FGAs) in youth because of their reduced propensity for causing extrapyramidal side effects as well as a stronger evidence base to support their use, their safety profiles require careful consideration. Weight gain, metabolic syndrome, sedation, extrapyramidal symptoms, and endocrine effects have been reported in youth with schizophrenia. Such side effects can significantly impact adherence and long-term physical health, necessitating the need for ongoing monitoring and thoughtful agent selection tailored to each patient’s individual clinical profile and risk factors. Overall, current evidence supports SGAs as the foundation of psychopharmacologic treatment for schizophrenia in pediatric-aged patients, with clozapine reserved for refractory cases. However, the relative paucity of pediatric-specific data compared with adult populations underscores the importance of continued research to guide clinical practice. In the meantime, accurate diagnosis, early intervention, and vigilant monitoring of both therapeutic response and side effects remain essential to optimizing outcomes for youth with schizophrenia.

Key Points

This review synthesizes current evidence on the diagnosis and pharmacologic treatment of schizophrenia in children and adolescents, emphasizing the importance of accurate diagnosis to guide clinical care.

We summarize clinical trial data on antipsychotics, highlighting agents with demonstrated efficacy (risperidone, aripiprazole, quetiapine, paliperidone, and lurasidone) as well as those without clear benefit (ziprasidone and asenapine) for treatment of youth with schizophrenia, and discuss the role of clozapine in treatment-resistant cases.

Particular attention is given to differences in side-effect profiles, including metabolic risks, highlighting the need for careful risk–benefit analysis, individualized treatment planning, and ongoing monitoring.

Introduction

Historical and Conceptual Foundations of Schizophrenia Diagnosis

Schizophrenia is a chronic psychiatric disorder marked by impaired reality testing, typically emerging in adolescence or early adulthood [1]. Although one of the earliest mental illnesses to be described, its diagnostic criteria have evolved significantly over time [2, 3]. Kraepelin initially described schizophrenia in 1899 as dementia praecox, emphasizing early cognitive decline [4]. Bleuler later introduced the term schizophrenia and differentiated between “basic” symptoms, such as affective disturbances, ambivalence, autistic thinking, and loosening of associations, and “accessory” symptoms, such as hallucinations and delusions [5]. Schneider subsequently introduced so-called first-rank positive symptoms [4]. The lack of alignment between these frameworks may reflect limited consistency in the diagnostic criteria of schizophrenia at that time.

With the introduction of schizophrenia in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III), the criteria were refined to prioritize observable features such as delusions, hallucinations, and functional decline [6]. Later revisions incorporated additional negative symptoms [7]. Current DSM criteria are the same for both adult and pediatric populations and require a mix of positive and negative symptoms, with evidence of functional impairment and a duration of at least 6 months to meet diagnostic symptom criteria [1].

Prevalence

While the diagnostic framework is consistent across age groups, the epidemiologic patterns appear to differ across developmental stages. The prevalence of schizophrenia is significantly lower in pre-adolescent children than in adults. Childhood-onset schizophrenia (COS), defined as onset before age 13 years, affects approximately 0.05% of the general population [8]. Early onset schizophrenia (EOS), occurring between ages 13 and 17 years, is diagnosed in about 0.25% of youth [8]. In comparison, the lifetime prevalence in adults approaches 1% [9, 10]. Approximately 3% of patients with schizophrenia develop the disorder before age 14 years and 12.3% before age 18 years [11].

Gender differences in prevalence have also been observed, though findings are less consistent in pediatric populations. Among adults, male individuals are approximately 1.4 times more likely to be diagnosed with schizophrenia than female individuals [12]. In youth, however, the data are mixed, with some studies reporting higher rates in male and others in female individuals [8, 10, 13, 14]. These discrepancies may be explained, at least in part, by sex-related differences in age of onset. Schizophrenia tends to emerge earlier in male than in female individuals [12], with approximately one-third of males developing the illness during adolescence, compared with about 18% of females. Consequently, male individuals are more likely than female individuals to develop schizophrenia during adolescence [15].

Long-Term Outcomes and Prognosis

Beyond prevalence, EOS is associated with substantial long-term morbidity and functional burden. Historically, outcomes in EOS were thought to be worse than those in adult-onset schizophrenia (AOS), with greater cognitive impairment, lower educational attainment, and higher rates of residual symptoms and disability [16, 17]. For example, a meta-analysis found that younger age of onset was associated with more frequent hospitalizations, greater severity of negative symptoms, higher relapse rates, and poorer social and occupational functioning [18].

However, emerging data challenge the notion of uniformly worse outcomes in EOS. A comprehensive Danish registry study involving over 16,000 individuals found that, although patients with EOS experienced longer initial hospitalizations, there were no significant differences in long-term readmission rates or annual inpatient days compared with patients with AOS [3]. Similarly, a 10-year follow-up study failed to find a correlation between age of onset of schizophrenia and functional outcomes in adulthood [19]. These findings indicate that certain aspects of EOS may present greater challenges, but not all long-term outcomes are necessarily worse than those observed in AOS. These results need to be interpreted with caution in light of the comparatively lower level of evidence relative to the earlier referenced meta-analysis.

One important factor influencing prognosis is the duration of untreated psychosis (DUP), which is approximately 3.5 times longer in youth than in adults [13, 20]. Longer DUP has been consistently associated with poorer outcomes, including lower cognitive functioning, impaired social development, and increased rates of comorbid mood and anxiety disorders in more than a third of individuals [9, 10, 21]. These findings underscore the importance of early detection and timely intervention in pediatric populations.

Diagnostic Challenges

Despite the availability of standardized diagnostic criteria, accurately identifying EOS remains a significant clinical challenge. Misdiagnosis—both over- and underdiagnosis—can lead to prolonged DUP and inappropriate treatment strategies.

Overdiagnosis is not uncommon and may stem partially from the high prevalence of psychotic-like experiences in youth. Studies indicate that up to 17% of children and 7.5% of adolescents report such symptoms [22–24]. However, these experiences are often transient and do not necessarily progress to schizophrenia. For instance, approximately 30–50% of youth referred with schizophrenia were ultimately not diagnosed with COS after comprehensive assessment [10].

Complicating the diagnostic process further, various psychiatric and medical conditions can present with psychotic features [25]. Mood disorders, schizoaffective disorder, substance use, post-traumatic stress disorder, developmental disabilities, and certain medical conditions can all manifest symptoms resembling those of COS [25]. Consequently, misdiagnosis may result in inappropriate pharmacological interventions, unnecessary side effects, and delays in addressing the underlying primary condition.

Conversely, underidentification poses its own risks. The prodromal phase of schizophrenia often includes negative symptoms and cognitive deficits, which can be mistaken for depression or attention deficit hyperactivity disorder [10, 26]. Substance use and existing medical conditions may also obscure the emerging psychotic pathology [13, 27]. Additionally, psychotic symptoms in children may be misinterpreted as imaginative play, obsessive–compulsive behaviors, or features of autism spectrum disorder [25]. Such misattributions can delay appropriate treatment, potentially leading to poorer outcomes [28].

Premorbid Symptoms and Prodrome

Given these diagnostic complexities, a longitudinal perspective during evaluation is essential. Predicting which youths with subthreshold symptoms will develop schizophrenia remains challenging [29]. The concept of “At Risk Mental States” (ARMS) was introduced and describes individuals who are more vulnerable to developing psychosis. This group includes those with attenuated psychotic symptoms, brief psychotic episodes, or a family history of psychosis accompanied by a decline in functioning [20]. While most individuals with ARMS do not progress to schizophrenia, they often exhibit deficits in verbal learning, sustained attention, and executive functioning compared with healthy controls [30]. Transition rates to psychosis among this group vary, with studies reporting 9.5–20% at 1 year, 12.1–23% at 2 years, and up to 16.1–23.3% at 3–5 years [21, 31].

Children who later develop schizophrenia often show impairments several years before the onset of psychotic symptoms [32]. These early, nonspecific signs may include speech delays, motor abnormalities, social skill deficits, and even intellectual impairments [33] (Table 1). Such premorbid features are more common in childhood-onset schizophrenia than in adolescent-onset cases [34]. For example, more than half of individuals who develop schizophrenia show early signs such as language delays, motor coordination issues, and social withdrawal [35]. Approximately 25% have symptoms of autism spectrum disorder prior to developing psychosis [36].

Table 1.

Developmental course of schizophrenia

Phase of illness	Characteristic symptoms	Other considerations
Premorbid phase	Speech and language delays Social skills deficits Motor coordination difficulties Cognitive or intellectual impairments	These symptoms are often nonspecific and may overlap with symptoms of neurodevelopmental disorders (e.g., autism or attention deficit hyperactivity disorder)
Prodromal phase	Social withdrawal Reduced engagement in activities of daily living Decline in academic performance Mood and affective changes Subtle unusual thoughts or behaviors Mild disorganization	In this phase, symptoms can often be subthreshold and variable, they may resemble depression or anxiety. This phase remains an important window for early diagnosis and intervention
Active illness phase	Positive symptoms (delusions, hallucinations) Negative symptoms (apathy, anhedonia, social withdrawal) Disorganized thoughts and behavior	Consider longitudinal course of illness, family history, as well as level of impairment

The prodromal phase of schizophrenia is typically marked by worsening across multiple domains of functioning, including social withdrawal, diminished self-care and hygiene, declining academic performance, and the emergence of bizarre or disorganized behaviors that may be subtle enough to escape notice by family or school personnel. Affective changes are also common, ranging from flat affect to increased irritability or anger [32].

Considering a diagnosis of schizophrenia during the prodromal phase is particularly challenging because early symptoms are often nonspecific. Nevertheless, many youths show impairments before the onset of overt psychosis. Careful attention to these subtle changes is important, as recognizing them can improve the diagnostic accuracy and allow for earlier intervention.

Diagnostic Distinctiveness of Schizophrenia

Schizophrenia can pose profound diagnostic challenges, as patients may present with a mixture of psychotic, mood, anxiety, and other psychiatric symptoms. Yet, when considered in its entirety, the constellation of symptoms that defines schizophrenia is truly distinctive—no other disorder replicates its breadth of positive and negative features combined with its characteristic longitudinal course (Table 1).

Schizophrenia is a polythetic disorder, lacking a single pathognomonic feature, and presentations can vary widely depending on the specific combination of expressed symptoms [37]. Accurate diagnosis therefore requires synthesizing findings across multiple clinical domains. Beyond prominent positive symptoms (delusions, hallucinations, or disorganization), careful evaluation of negative symptoms (e.g., affective flattening or avolition) is essential, as these features may be subtle yet diagnostically informative. Equally important is a longitudinal perspective: Distinguishing acute versus insidious onset, identifying precipitating factors, and tracking the evolution of symptoms over time can clarify diagnostic boundaries. Finally, given the substantial heritability of schizophrenia, systematic assessment of family psychiatric history should be incorporated into the diagnostic formulation.

Treatment Considerations

Accurate diagnosis of schizophrenia prior to initiating treatment is essential, as its early presentations can mimic other psychiatric conditions, such as mood, anxiety, or neurodevelopmental disorders. False-positive diagnosis of schizophrenia not only exposes youth to inappropriate treatments and unnecessary side effects but also delays the implementation of effective interventions. Without diagnostic precision, treatment is unlikely to be effective. Conversely, establishing accurate diagnosis allows for targeted interventions that improve symptom reduction, functional recovery, and long-term outcomes.

While accurate diagnosis of schizophrenia is a critical and oftentimes challenging first step, the subsequent implementation of appropriate treatment strategies is essential to address the multifaceted needs of children with schizophrenia and to improve their long-term outcomes. Treatment interventions for EOS encompass psychosocial, educational, supportive psychotherapeutic, and pharmacological approaches [38, 39]. Psychological interventions should be developmentally appropriate and consistently integrated across all phases of care, from acute episodes to recovery, with a strong emphasis on collaborative decision-making that actively involves young people and their families. Clinical guidelines, including those from the National Institute for Health and Care Excellence (NICE), as well as the guidelines from the American Academy of Child and Adolescent Psychiatry (AACAP), recommend combining antipsychotic medications with individual cognitive behavioral therapy and family-based interventions [38, 40]. Pharmacologic treatment should be initiated only after a thorough assessment and should be administered with caution owing to the elevated risk of adverse effects.

Treating schizophrenia in pediatric-aged patients poses significant clinical challenges, given the limited evidence base, the need to consider developmental factors, and the substantial burden of side effects associated with currently available pharmacological treatments [41]. Consequently, there is a critical need for safer and more effective therapeutic strategies for management of schizophrenia in youth [16]. Research priorities include evaluating the efficacy of psychosocial treatments, assessing the long-term efficacy and safety of antipsychotic medications, developing age-appropriate therapeutic frameworks, and implementing interventions to reduce antipsychotic-induced metabolic side effects.

To address unique needs of patients with schizophrenia and their families, specialized first-episode psychosis programs have been created. They emphasize timely access to comprehensive, evidence-based care, including optimized psychotherapy, coordinated multidisciplinary services and structured psychosocial intervention. They focus on family involvement, psychoeducation, and care coordination across clinical, school, and community settings. Some of these programs have been shown to both increase the quality of life of individuals with schizophrenia, as well as decrease the symptom burden [42, 43].

This review aims to synthesize the available evidence on the treatment of schizophrenia in children and adolescents in a manner that may be clinically useful. Specifically, it summarizes data on the efficacy and adverse event profiles of antipsychotic medications reported in clinical trials. For clarity and accessibility, the manuscript is organized by first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs). The literature search was conducted using multiple databases, including PubMed, MEDLINE, Embase, PsycINFO, the Cochrane Library, and ClinicalTrials.gov for studies published from database inception through February 2026. Studies were selected with a focus on findings most relevant to clinical practice.

Psychopharmacology of Schizophrenia

Psychopharmacologic Treatment Guidelines

When evaluating youth for schizophrenia, clinicians should conduct a thorough assessment of the child’s symptoms, obtain collateral information from caregivers, and consider using validated rating scales to assess psychotic symptoms [16]. The child’s age and cognitive functioning should be taken into account, with questions adjusted to ensure comprehension. Medical and other potential causes of psychosis must be ruled out prior to confirming a diagnosis of schizophrenia.

Several guidelines support the use of antipsychotic medications as the first-line treatment for youth with schizophrenia [16]. SGAs are generally preferred and most commonly prescribed; however, FGAs may be equally effective, though most head-to-head efficacy trials have been conducted in adults. Antipsychotics that are approved by the Food and Drug Administration (FDA) for adolescents with schizophrenia include aripiprazole, risperidone, paliperidone, quetiapine, olanzapine, lurasidone, and brexpiprazole.

First-Generation Antipsychotics (FGAs)

FGAs, as the earliest available antipsychotic medications, were also the first to be studied in youth for treatment of schizophrenia. Unfortunately, the evidence on their use in this population is limited, and many studies do not have consistent methodology, including variability in diagnostic criteria and symptom severity, and lack of standardized measures of treatment response. Despite these limitations, the studies offer valuable insight into the use of FGAs in youth with schizophrenia [44]. Overall, available trials demonstrated the benefit of FGAs in reducing symptoms of schizophrenia in youth.

For example, Pool et al. [45] compared haloperidol, loxapine, and placebo in adolescents, finding that youth with more severe symptoms showed greater improvement with both FGAs compared with placebo (Table 2). Similarly, Spencer et al. reported that haloperidol was significantly more effective than placebo in improving positive psychotic symptoms [46].

Table 2.

Select randomized trials of antipsychotics in youth with early onset schizophrenia

Study	Medication	Daily dose	N	Age, years	Study design	Duration	Outcome measure	Results
Kumra, 1996 [53]	Clozapine Haloperidol	Max 525 mg Max 27 mg	10 11	6–18	Randomized, double-blind	6 weeks	SANS	Clozapine was superior to haloperidol (p = 0.04–0.002)
Shaw, 2006 [73]	Clozapine Olanzapine*	Max 900 mg/day Max 30 mg/day	12 13	7–16	Randomized, double blind	8 weeks	CGI-S SANS	Greater improvement on SANS with clozapine, compared with olanzapine
Findling, 2008 [60]	Aripiprazole* high Aripiprazole* low Placebo	30 mg 10 mg	102 100 100	13–17	Randomized, double-blind, placebo controlled	6 weeks	PANSS score change compared with baseline	− 28.6 − 26.7 − 21.2
Kumra, 2008 [72]	Clozapine Olanzapine*	Max 900 mg Max 30 mg	18 21	10–18	Randomized, double blind	12 weeks	> 30% improvement in BPRS score	66% improved 33% improved
Sikich, 2008 [51]	Risperidone* Olanzapine* Molindone	0.5–6 mg 2.5–20 mg 10–140 mg	41 35 40	8–19	Randomized, placebo-controlled	8 weeks	> 20% improvement in PANNS score	46% improved 34% improved 50% improved
Haas, 2009 [54]	Risperidone* Risperidone*	1.5–6.0 mg 0.15–0.6 mg	125 132	13–17	Randomized, double-blind	8 weeks	≥ 20% reduction in PANSS score	73% responded 50% responded
Haas, 2009 [55]	Risperidone*high Risperidone* low Placebo	4–6 mg/day 1–3 mg/day	51 55 54	13–17	Randomized, double-blind, placebo controlled	6 weeks	≥ 20% reduction in PANSS score	72% 65% 35%
Kryzhanovskaya, 2009 [56]	Olanzapine* Placebo	2.5–20 mg	72 35	13–17	Randomized, double-blind, placebo controlled	6 weeks	BPRS total score change	− 19.4 − 9.3
Singh, 2011 [63]	Paliperidone* low Paliperidone* medium Paliperidone* high Placebo	3 mg 6 mg 12 mg	48 54 47 51	12–17	Randomized, double-blind, placebo controlled	6 weeks	PANSS score change compared with baseline	− 19.0 − 13.8 − 16.3 − 7.9
Findling, 2012 [58]	Quetiapine* high dose Quetiapine* low dose Placebo	800 mg 400 mg	74 73	13–17	Randomized, double-blind, placebo controlled	6 weeks	PANSS score change compared with baseline	− 28.44 − 27.31 − 19.5
Savitz, 2015 [64]	Paliperidone* Aripiprazole*	3–9 mg 2–15 mg	113 115	12–17	Randomized, double-blind study	18 weeks	PANNS score change from baseline	− 25.6 − 26.8
Findling, 2015 [65]	Asenapine low Asenapine high Placebo	2.5 mg BID 5 mg BID	98 106 102	12–17	Randomized, double-blind, placebo controlled	8 weeks	PANSS score change compared with placebo	− 4.8 − 5.6
Goldman, 2017 [66]	Lurasidone* low Lurasidone* high Placebo	40 mg 80 mg	108 106 112	13–17	Randomized, double-blind, placebo controlled	6 weeks	PANSS score change compared with baseline	− 18.6 − 18.3 − 10.5
Pagsberg, 2017 [75]	Aripiprazole* Quetiapine* ER	20 mg 600 mg	58 55	12–17	Randomized, double blind	12 weeks	PANSS positive score	− 6.21 − 5.05
Ward, 2025 [77]	Brexpiprazole* Aripiprazole* Placebo	2–4 mg 10–20 mg	110 102 104	13–17	Randomized, placebo controlled	6 weeks	PANNS total score change from baseline	− 22.8 − 24.0 − 17.4

Medications marked by “*” are approved for treatment of schizophrenia in youth by the US Food and Drug Administration (FDA)

BID, twice daily; BPRS, Brief Psychiatric Rating Scale; CGI-S, Clinical Global Improvement, Severity; PANNS, Positive and Negative Syndrome Scale; SANS, Schedule for the Assessment of Negative/Positive Symptoms

Other randomized, double-blind trials directly compared the efficacy of different FGAs. These studies generally found comparable outcomes between fluphenazine and haloperidol [47], loxapine and haloperidol [48], and thiothixene and thioridazine [49].

While these early head-to-head trials focused on comparing different FGAs, subsequent research examined how FGAs perform relative to SGAs. One of the landmark studies in this area is the Treatment of Early-Onset Schizophrenia Study (TEOSS) [50]. In this trial, 116 participants aged 8–19 years were randomly assigned to receive risperidone, olanzapine, or molindone for 8 weeks [51]. Participants who responded to their initial treatment continued on the same medication, in blinded fashion, for an additional 44 weeks [52]. The study did not demonstrate a significant difference in efficacy between the SGAs and molindone (Table 2). Notably, only 12% of participants remained on their originally assigned treatment for the full 52 weeks. Reasons for discontinuation included inadequate efficacy, adverse events, and nonadherence with study procedures. During the 44-week extension, no significant differences in adverse events were reported between the treatment groups [52] (Table 3).

Table 3.

Common adverse events of antipsychotic medications noted in select studies

Study	Medication	Adverse events
Kumra, 1996 [53]	Haloperidol Clozapine	Insomnia Drowsiness, increased salivation, neutropenia, seizures
Shaw, 2006 [73]	Clozapine Olanzapine	Increased incidence of AEs overall Hypertension, tachycardia, enuresis, ECG abnormalities, increased appetite, hypersalivation Increased appetite, hypersalivation somnolence
Kumra, 2008 [72]	Clozapine Olanzapine	Upper bowel obstruction (N = 1), diabetes, weight gain, metabolic abnormalities Weight gain, metabolic abnormalities
Sikich, 2008 (TEOSS) [51]	Olanzapine Risperidone Molindone	Weight gain, increase in appetite, cholesterol, lipoprotein, insulin, and liver transaminase Weight gain, constipation, prolactin elevation Akathisia
Findling, 2008 [60, 73]	Aripiprazole versus placebo	EPS, somnolence, tremor, headache, nausea, dizziness
Haas, 2009 [54]	Risperidone	Dystonia, tremor, akathisia, prolactin elevation, weight gain
Kryzhanovskaya, 2009 [56]	Olanzapine versus placebo	Weight gain, somnolence, headache, increased appetite, sedation, dizziness
Singh, 2011 [63]	Paliperidone versus placebo	Weight gain, akathisia, elevation in prolactin, headache, somnolence, tremor
Findling, 2012 [58]	Quetiapine versus placebo	Weight gain, somnolence, insomnia, headache, increase in total cholesterol and triglycerides, dizziness, EPS
Findling, 2015 [65]	Asenapine versus placebo	Weight gain, somnolence, sedation, hypersomnia, akathisia, EPS, fasting glucose elevation
Goldman, 2017 [66] Correll, 2022 [68]	Lurasidone versus placebo	Nausea, somnolence, akathisia, vomiting, sedation, somnolence, headache
Ward, 2025 [77]	Brexpiprazole	Headache, nausea, somnolence, akathisia, fatigue

AE, adverse events; ECG, electrocardiogram, EPS, extrapyramidal symptoms

Another study compared the efficacy of clozapine and haloperidol in treatment-resistant youth with schizophrenia [53]. This trial included 21 participants aged 6–18 years who had not responded to at least two prior antipsychotic trials. Participants were randomized to receive either clozapine (maximum daily dose 525 mg) or haloperidol (maximum daily dose 27 mg) for 6 weeks; those in the haloperidol group also received adjunctive benztropine. Clozapine demonstrated superiority over haloperidol in reducing both positive and negative symptoms (Table 2). However, participants treated with clozapine were more likely to experience serious adverse events, including seizures and neutropenia (Table 3).

Second-Generation Antipsychotics (SGAs)

SGAs, with the exception of clozapine, are generally used as first-line agents in the treatment of schizophrenia. This preference reflects their lower risk of extrapyramidal symptoms (EPS) and greater efficacy in managing negative symptoms compared with FGAs [32]. In addition, unlike FGAs, the evidence base for SGAs in the treatment of schizophrenia in youth is broader, consisting of a larger number of studies of methodological rigor that include both placebo-controlled trials and head-to-head comparisons among different SGAs.

Dose Comparison Studies and Placebo-Controlled Studies

The efficacy of two risperidone dosing strategies was evaluated in a randomized controlled trial of 257 adolescents aged 13–17 years [54]. The trial compared a higher dose (1.5–6.0 mg/day) with a lower dose (0.15–0.6 mg/day) of risperidone for the treatment of schizophrenia in youth (Table 2). The study showed that adolescents assigned to the higher dose demonstrated greater improvement in symptoms compared with those receiving the lower dose. However, the higher dose was also associated with more adverse events, including dystonia, tremor, akathisia, and somnolence. Participants in the higher-dose risperidone group gained 3.2 kg over the course of the trial, compared with 1.7 kg in the lower-dose group.

Another randomized trial compared two doses of risperidone with placebo in 160 adolescents aged 13–17 years with schizophrenia [55]. Participants were assigned to a higher-dose group (4–6 mg/day), a lower-dose group (1–3 mg/day), or placebo. Both risperidone groups demonstrated significant improvements in psychotic symptoms compared with placebo. However, adolescents in the higher-dose group were more likely to experience EPS, dizziness, and hypertonia than those receiving the lower dose.

The efficacy of olanzapine was evaluated in a 6-week randomized placebo-controlled trial of 107 adolescents aged 13–17 years with schizophrenia [56]. Youth treated with olanzapine showed significantly greater improvement in symptoms compared with placebo (Table 2). A post hoc analysis further demonstrated that early response by week 3 predicted subsequent response or remission at week 6 [57]. Olanzapine was associated with higher rates of adverse events, including substantial weight gain (mean 4.3 kg versus 0.1 kg with placebo), as well as elevations in prolactin and triglycerides [56]. Owing to its association with significant weight gain, olanzapine is not recommended as a first-line treatment for schizophrenia in youth.

Quetiapine was examined in a 6-week randomized placebo-controlled trial of 220 adolescents aged 13–17 years with schizophrenia [58]. Participants were assigned to receive either 400 mg/day, 800 mg/day, or placebo (Table 2). Both quetiapine groups demonstrated significant reductions in psychotic symptoms compared with placebo, with the higher-dose group separating from placebo earlier (day 14 versus day 21). Adverse events in quetiapine groups included weight gain, increases in total cholesterol and triglycerides, as well as somnolence, insomnia, and headache (Table 3).

The efficacy of ziprasidone was evaluated in a randomized, placebo-controlled trial of 283 adolescents aged 13–17 years with schizophrenia [59]. Participants received ziprasidone (40–160 mg/day) or placebo during the 6-week week acute trial, followed by a 26-week open-label extension. Early termination of the study was recommended owing to lack of efficacy, as no significant differences were observed between treatment groups on the primary outcome—change in the Brief Psychiatric Rating Scale-Anchored (BPRS-A) score. Common adverse events included somnolence and EPS. Notably, one participant died by suicide during the open-label extension phase.

Aripiprazole was evaluated in a 6-week randomized, placebo-controlled trial of 302 adolescents aged 13–17 years with schizophrenia [60]. Participants were randomized to receive aripiprazole 10 mg/day, 30 mg/day, or placebo (Table 2). Both active treatment groups demonstrated significant improvements in psychotic symptoms compared with placebo, with the higher-dose group showing earlier separation from placebo. Approximately half of patients receiving aripiprazole achieved remission (54% in the 10 mg/day group and 58% in the 30 mg/day group) versus 36% in the placebo group. Early clinical response within the first 3 weeks predicted higher likelihood of remission by study endpoint [61]. Adverse events associated with aripiprazole included EPS, tremor, and somnolence, with a greater incidence in the higher-dose group. Prolactin levels decreased across both active treatment arms, and mean weight gain was minimal (0.2 kg).

Long-term efficacy of aripiprazole was demonstrated in a 52-week double-blind, placebo-controlled withdrawal trial in adolescents aged 13–17 years [62]. Participants were first stabilized on aripiprazole 10–30 mg/day and then randomized to continue active treatment or switch to placebo. Those maintained on aripiprazole had significantly longer time to relapse compared with placebo. Notably, treatment-emergent adverse events occurred less frequently in the aripiprazole group than in the placebo group.

The efficacy of different doses of paliperidone was evaluated in a 6-week randomized controlled trial of 201 adolescents aged 12–17 years with schizophrenia, compared with placebo [63]. The study demonstrated that paliperidone at doses of 3–12 mg/day significantly reduced psychotic symptoms relative to placebo and suggested that weight-based dosing is not necessary for this medication (Table 2). Adverse events were dose-dependent and included akathisia, tremor, somnolence, and headache (Table 3). Weight gain was greater in participants receiving a higher dose of paliperidone (1.4 kg) compared with placebo (0.3 kg)

Long-term efficacy and safety of paliperidone were assessed in a 2-year open-label extension study involving 400 youth aged 12–17 years [64], using flexible doses of up to 12 mg/day. Overall, 41.7% of participants achieved remission. Common adverse events included weight gain, somnolence, akathisia, tremor, hyperprolactinemia, and, in some cases, worsening of psychotic symptoms.

The short-term safety and efficacy of asenapine were evaluated in an 8-week randomized controlled trial comparing two doses (2.5 mg and 5 mg twice daily) with placebo [65]. Participants who completed the acute phase were eligible for a 26-week open-label extension. In the acute trial, neither dose separated from placebo on the primary outcome measure, Positive and Negative Syndrome Scale (PANSS), although both showed numerical improvements that were maintained during the extension (Table 2). Reported adverse events included weight gain, sedation, and akathisia.

The efficacy of lurasidone for schizophrenia in youth was evaluated in a 6-week, double-blind, placebo-controlled trial comparing two doses (40 and 80 mg/day) with placebo [66]. The study enrolled participants aged 13–17 years with a diagnosis of schizophrenia. Both lurasidone doses produced significant improvement in psychotic symptoms compared with placebo (Table 2). Treatment response, defined as a ≥ 20% reduction in PANSS total score, was achieved in 63.9% of participants on 40 mg/day, 65.1% on 80 mg/day, and 42% on placebo. Notably, youth who do not respond to 80 mg/day may benefit from increasing the dose to 160 mg/day [67]. Common adverse events of lurasidone included nausea, vomiting, somnolence, and akathisia.

Long-term safety and effectiveness of lurasidone were examined in a 2-year open-label extension study [68]. Continued treatment with lurasidone was associated with sustained improvement on the PANSS, with a mean score reduction of 18.4 points at week 104. No significant weight changes were observed. Reported long-term adverse events included headache, anxiety, nausea, and sedation.

Cariprazine was recently approved by the FDA for the treatment of schizophrenia in adolescents aged 13 years and older [69]. This approval was supported by an extrapolation strategy based on efficacy data from adult clinical trials [70]. Extrapolation has been considered appropriate from some regulators when the underlying disease course and treatment response are sufficiently similar between adult and pediatric populations, as is generally regarded to be the case in schizophrenia. In addition, pharmacokinetic studies of cariprazine in adolescents have demonstrated parameters comparable to those observed in adults [71], further supporting dose selection and regulatory approval in this age group.

Comparison Studies of SGAs

Several comparison studies between SGAs have been conducted to evaluate their relative efficacy, speed of response, and side-effect profiles in youth with schizophrenia. These studies are particularly useful for guiding treatment choices, as they help clinicians balance symptom improvement with minimizing adverse effects. The following section summarizes key short- and long-term trials of commonly used SGAs in adolescents, highlighting both efficacy and tolerability.

Extending research on individual SGAs, some trials have directly compared the effectiveness of different antipsychotics in treatment-resistant youth. Kumra et al. [72] conducted a randomized controlled trial in 39 children and adolescents aged 10–18 years with schizophrenia who had not responded to at least two prior antipsychotics (Table 2). Participants were assigned to clozapine (maximum 900 mg/day) or olanzapine (maximum 30 mg/day). A greater proportion of youth on clozapine (66%) responded to treatment compared with those on olanzapine (33%). Both groups experienced weight gain and metabolic abnormalities relative to baseline. The trial included a 12-week open-label extension in which nonresponders to olanzapine were switched to clozapine, with seven of ten participants showing response. Overall, 71% of youth on clozapine developed hypertriglyceridemia, and 29% had fasting glucose above 100 mg/dL.

Similarly, Shaw [73] found that clozapine was superior to olanzapine in reducing negative symptoms during 8 weeks of acute treatment in treatment-resistant youth, with improvements sustained over a 2-year follow-up (Table 2). Together, these studies highlight the enhanced efficacy of clozapine in youth who do not respond to other antipsychotics, alongside notable metabolic risks. The risks and benefits of clozapine need to be discussed with patient and family, when considering initiation of treatment with clozapine. Other than potentially life-threatening neutropenia, bowel obstruction that might lead to paralytic ileus has been reported in adult patients [74].

Another study has compared the efficacy and tolerability of aripiprazole with extended-release quetiapine in adolescents with schizophrenia [75]. Both groups showed improvement in positive symptoms over 12 weeks, with no statistically significant differences between the medications. However, youth treated with quetiapine experienced more rapid and greater weight gain, whereas aripiprazole was more frequently associated with akathisia early in the trial.

Another head-to-head comparison study evaluated efficacy and safety of paliperidone extended release (ER) and aripiprazole in a double-blind trial of adolescents aged 12–17 years with schizophrenia [64]. Flexible dosing was used for both medications (paliperidone 3–9 mg/day; aripiprazole 2–15 mg/day). No significant differences were observed between groups in reducing psychotic symptoms during the 8-week acute phase or the 18-week maintenance phase, as both treatments were associated with improvement. At study endpoint, 76.8% of participants receiving paliperidone and 81.6% receiving aripiprazole met response criteria. Common adverse events with paliperidone included akathisia, headache, somnolence, tremor, and weight gain, while aripiprazole was associated with reports of somnolence and, in some cases, worsening schizophrenia symptoms. EPS were more frequent with paliperidone than with aripiprazole.

A head-to-head, 12-week open-label trial compared risperidone, aripiprazole, and olanzapine in 30 youth aged 10–18 years with schizophrenia spectrum disorders [76]. No significant differences in efficacy were observed between groups on the PANSS.

Efficacy of brexpiprazole was compared with aripiprazole in a randomized controlled trial of adolescents aged 13–17 years with schizophrenia [77]. Participants were assigned to brexpiprazole (2–4 mg/day), aripiprazole (10–20 mg/day), or placebo. Both active treatments significantly reduced psychotic symptoms compared with placebo. Remission rates were 29.1% for brexpiprazole, 35.6% for aripiprazole, and 23.3% for placebo. Brexpiprazole was associated with headache and nausea.

Although antipsychotics are effective in treating psychotic symptoms in youth with schizophrenia, their use is frequently associated with adverse effects, particularly metabolic complications, including weight gain, which may have long-term health consequences. To mitigate antipsychotic-associated weight gain, several studies have examined the role of metformin as a preventive or adjunctive intervention [78–80]. Recent clinical guidelines have been published to assist clinicians in determining when metformin initiation may be appropriate [81].

Conclusions

Accurate diagnosis of schizophrenia in youth remains a critical first step in ensuring appropriate and effective treatment. Among available pharmacologic interventions, the most robust evidence supports the use of SGAs, many of which have demonstrated efficacy in reducing symptom burden in youth with schizophrenia. However, not all SGAs appear equally effective in this population, as studies of ziprasidone and asenapine have not shown clear benefit. While multiple agents have efficacy for this indication, their side-effect profiles differ considerably, with metabolic, neurologic, and sedative complications that can affect both short- and long-term outcomes. In particular, olanzapine is generally not recommended as a first-line treatment given its high risk of significant metabolic side effects. Clozapine remains reserved for treatment-resistant cases and, although highly effective in this context, requires careful monitoring owing to risks such as agranulocytosis and seizures. While long-acting injectable antipsychotics are not well studied in children and adolescents, they have shown to be effective in adults with schizophrenia, and more studies are needed to assess efficacy of these agents in youth. Taken together, these considerations highlight the need for a thoughtful risk–benefit analysis, individualized treatment planning, education of patient and family, and vigilant monitoring to optimize care for youth with schizophrenia.

Funding

None.

Declarations

Conflicts of interest

Dr. Findling receives or has received research support, acted as a consultant and/or has received honoraria from Abbvie, Ajna, Akili, Aluco, American Academy of Child & Adolescent Psychiatry, American Psychiatric Press, Bioprojet, BioXcel, Bristol Myers Squibb, Corium, Elsevier, Intra-Cellular Therapies, Iqvia, Karuna, Lundbeck, Maplight, Merck, MJH Life Sciences, NIH, Novartis, Otsuka, Oxford University Press, PaxMedica, PCORI, Pfizer, Radius, Sage, Signant Health, Sumitomo Pharma, Sunovion, Supernus Pharmaceuticals, Takeda, Tris, Viatris and Xenon. Dr. Stepanova received research support from PaxMedica and honoraria from American Academy of Child and Adolescent Psychiatry and American Psychiatric Press. Dr. Shah, Prajapati, and Cordrey and Mr. Nichols do not have conflicts of interest to report.

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Author contributions

Dr. Findling: conceptualization, supervision, and writing—review and editing; Dr. Shah, Prajapati, Cordrey and Mr. Nichols: writing—review and editing and literature review; Dr. Stepanova: conceptualization, supervision, writing—literature review, editing, and writing. All authors contributed to interpretation of the literature, revised the manuscript for content, and approved the final version for submission. All authors agree to be accountable for all aspects of the work.