A Clinical Trial of Adjunctive Thyroxine for Avolition in Schizophrenia

The goal of this clinical trial is to investigate whether adjunctive thyroxine treatment can ameliorate motivation deficits in adults with schizophrenia experiencing predominant avolition (core negative symptom).

The main questions it aims to answer are:

* Does adjunctive thyroxine reduce avolition symptoms compared to placebo? * Does adjunctive thyroxine normalize cortico-striatal circuit activity during reward processing?

Researchers will compare the treatment group (adjunctive sodium tablets, 50μg/day) with the control group (dose-equivalent placebo starch tablet) to see if thyroid hormone:

1. Significantly improves clinical scores of avolition 2. Modulates neural activation in motivation-processing brain circuits

Participants will:

* Maintain stable antipsychotic therapy for 8 weeks * Receive daily levothyroxine/placebo tablets * Complete the following assessments pre-/post-treatment: * Clinical evaluations (PANSS, NSA, PSP) * MRI scans (resting-state, structural, fMRI during reward tasks) * Blood tests * Behavioral motivation tasks

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Key information

Conditions

Schizophrenia Avolition Mental Disorders Schizophrenia Spectrum and Other Psychotic Disorders

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Meet the diagnostic criteria for schizophrenia according to the International Classification of Diseases, 10th Revision (ICD-10) (World Health Organization, 1993);
Aged between 18 and 45 years, right-handed;
Currently clinically stable, with the primary antipsychotic medication formulation and dosage unchanged for at least 4 weeks, and a total PANSS score ≤ 60;
Predominant avolition symptoms, defined as a score ≥ 16 on the Motivation subscale of the Negative Symptom Assessment (NSA-15) (Zhou et al., 2023), with fewer than 3 items scoring ≥ 4 and fewer than 2 items scoring ≥ 5 on the PANSS positive subscale (Rabinowitz et al., 2013);
Receiving one or two second-generation antipsychotics (SGAs), with stable medication doses for at least 1 month;
Willingness and ability to maintain stable medication doses throughout the trial period;
Capacity to understand study procedures, cooperate with all testing requirements, and provide written informed consent.

Exclusion criteria

Current treatment with clozapine or first-generation antipsychotics;
Current use of thyroid hormone medications or presence of thyroid dysfunction;
Hypersensitivity to levothyroxine sodium; or history of non-hypothyroid-related heart failure, tachyarrhythmias, or recent myocardial infarction;
Current use of medications known to interact with levothyroxine sodium that may affect its efficacy or safety (e.g., antidiabetic drugs, coumarin derivatives);
History of endocrinological or cardiovascular/cerebrovascular diseases;
IQ < 80 assessed by the Chinese short-form Wechsler Adult Intelligence Scale (Gong, 1981);
History of substance abuse or drug addiction;
History of traumatic brain injury or neurological disorders;
Receiving electroconvulsive therapy (ECT) within the last 3 months;
Pregnancy, lactation, or planning pregnancy within the next 2 months (for female participants);
Claustrophobia; implanted metal devices (e.g., prosthetic implants, pacemakers); or other contraindications to MRI scanning.

Treatment and study plan

Antipsychotics plus Levothyroxine Sodium

Drug

Maintain the original antipsychotic regimen combined with levothyroxine sodium tablets (Euthyrox), 50 μg/day for 8 weeks. Manufacturer: Merck Serono Ltd. Levothyroxine Sodium Tablets should be administered as a single daily dose on an empty stomach, 30 minutes before breakfast, with sufficient liquid (e.g., half a glass of water).

Antipsychotics plus Placebo

Drug

All participants maintain pre-study antipsychotic medication at stable doses. ADDITIONALLY, they receive a visually identical placebo tablet.

Placebo characteristics & Blinding guaranteet: Matches levothyroxine in appearance (size/color/coating), taste, and packaging.

Active ingredien : starch tablet with no biological activity. Administration: Once daily in the morning under identical fasting conditions.

Primary outcomes

the score of Motivation subscale of the Negative Symptom Assessment (NSA-15)

Time frame: Baseline, 2-week follow-up, 4-week follow-up, 6-week follow-up, 8-week follow-up

Secondary outcomes

Motivational deficits(avolition) measured by N2 (Emotional Withdrawal) and N4 (Passive/Apathetic, Social Withdrawal) items in the Positive and Negative Syndrome Scale (PANSS).

Time frame: Baseline, 2-week follow-up, 4-week follow-up, 6-week follow-up, 8-week follow-up
Performance of the monetary incentive delay task (MID)

Time frame: baseline, 8-week follow-up
Performance of the Effort-Expenditure for Rewards Task (EEfRT)

Time frame: baseline, 8-week follow-up

Sponsors and collaborators

Lead sponsor

Peking University

Other

Registry information

Important dates

Study start: 2025
Primary completion: 2027
Study completion: 2027
First posted: Jun 10, 2025
Registry last updated: Jun 10, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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Completed