GLP-1 & Mental Health UK: Suicidal Thoughts — MHRA Investigation

In 2023, the European Medicines Agency (EMA) and Iceland's Medicines Agency began reviewing spontaneous reports — submitted through national pharmacovigilance systems including the UK's MHRA Yellow Card scheme — of suicidal thoughts and self-harm in patients taking GLP-1 receptor agonists, principally semaglutide and liraglutide.

The trigger was an accumulation of Yellow Card and EudraVigilance reports flagging suicidal ideation as a potential adverse event. As GLP-1 prescribing volumes soared following the expansion of Ozempic, Wegovy and Mounjaro use for weight management, the absolute number of such reports increased — prompting the EMA's PRAC (Pharmacovigilance Risk Assessment Committee) to initiate a formal signal assessment.

In the UK, the MHRA was an active participant in the EMA review given the shared scientific data exchange framework that remained in place post-Brexit. The investigation was significant enough to attract mainstream media attention in the UK, particularly given the rapid growth in private GLP-1 prescribing.

It is important to understand from the outset that signal detection in pharmacovigilance does not establish causality — it identifies patterns in adverse event reports that warrant deeper investigation. The crucial question was whether GLP-1 drugs were causing suicidal thoughts, or whether patients taking these drugs had pre-existing mental health vulnerabilities.

After conducting a comprehensive review of available evidence — including clinical trial data, post-marketing surveillance reports, and epidemiological studies — the EMA PRAC published its conclusions in 2024.

Key findings: - A causal relationship between GLP-1 receptor agonists and suicidal or self-harm thoughts could not be established based on the available evidence - Clinical trials of semaglutide (SUSTAIN, STEP, SELECT) and liraglutide (LEADER, SCALE) did not show an increased incidence of suicidal ideation compared to placebo - Post-marketing reports, whilst present, were confounded by high baseline rates of depression and anxiety in populations with obesity — conditions that are independently associated with elevated suicide risk - The PRAC concluded that the benefit-risk balance of GLP-1 agonists remains favourable and no labelling change specifically requiring a suicidal ideation warning was mandated for the general population

However, the investigation produced two practical outcomes: 1. The EMA recommended that prescribers be reminded of the importance of monitoring for mental health changes in GLP-1 users, particularly those with pre-existing psychiatric conditions 2. Enhanced pharmacovigilance — specifically continued monitoring of suicidal ideation signals — was retained in the ongoing safety review requirements for semaglutide and related agents

The MHRA echoed these conclusions in its UK-specific communications and added updates to relevant product information to prompt clinical awareness, without issuing a contraindication.

Beyond the suicidal ideation investigation, the relationship between GLP-1 medications and broader mental health is complex and, in some respects, potentially positive.

Emerging evidence on mood and wellbeing: - Several observational studies and post-hoc analyses from clinical trials suggest that GLP-1 medications may have modest positive effects on mood in patients with depression, potentially mediated through weight loss, reduced inflammation, and direct central nervous system effects (GLP-1 receptors are expressed in the brain, including in areas regulating reward and mood) - Some researchers have proposed that GLP-1 agonists may reduce addictive behaviours including alcohol, nicotine and food addiction, through mechanisms involving dopaminergic pathways — though this remains investigational

Risk factors that warrant monitoring: - Patients with pre-existing severe depression, bipolar disorder, or a history of suicidal ideation represent a population where closer monitoring is appropriate during GLP-1 initiation - Rapid weight loss — which GLP-1 drugs can produce — is associated with psychological adjustment challenges for some patients, including changes in body image and identity - The stimulant effect of markedly reduced appetite can occasionally cause fatigue, mood changes and irritability, particularly during the early titration phase

UK clinical guidance: In UK primary care and private prescribing, best practice includes a brief mental health screening at baseline (using validated tools such as PHQ-9 for depression or GAD-7 for anxiety) for patients initiating GLP-1 therapy, particularly those with a known psychiatric history.

Regardless of the regulatory conclusions about causality, patients and their carers should be aware of the mental health changes that may occur during GLP-1 treatment — whether related to the drug, the weight loss process, or pre-existing conditions.

Signs that warrant prompt contact with your prescriber or GP: - New or worsening feelings of hopelessness, worthlessness or profound sadness lasting more than two weeks - Thoughts of harming yourself or ending your life — seek urgent help immediately if this occurs (call your GP, go to A&E, or call 116 123 / Samaritans) - Significant sleep disturbance (inability to sleep, or sleeping excessively) that is not explained by other factors - Marked mood changes — unusual irritability, emotional flatness, or feeling disconnected - Withdrawal from activities and relationships that were previously enjoyable

Distinguishing drug effects from adjustment challenges: Some GLP-1 users experience a period of psychological adjustment as appetite suppression alters their relationship with food — for those who have used food as emotional comfort, removing that driver can unmask underlying distress. This is not a drug side effect per se, but it is a real phenomenon that clinical teams supporting weight management should address.

Immediate resources in the UK: - Samaritans: 116 123 (24 hours, free) - Crisis text line: Text SHOUT to 85258 - 999 or A&E if there is immediate risk - GP urgent appointment or 111 for non-emergency urgent mental health concerns

The UK pharmacovigilance system depends on reporting of suspected adverse effects to build the evidence base for drug safety — including the investigation that prompted the mental health review. If you experience any mental health changes that you believe may be related to your GLP-1 medication, reporting is valuable.

The Yellow Card scheme: The MHRA Yellow Card is the UK's system for reporting suspected adverse drug reactions. It can be completed by patients, carers, or healthcare professionals. Reports can be submitted: - Online at yellowcard.mhra.gov.uk - Through the Yellow Card app (available on iOS and Android) - By post using a paper Yellow Card form (available from pharmacies)

What to include in a Yellow Card report: - The medication name, dose, and dates of treatment - A description of the reaction, when it started, and how severe it was - Your relevant medical history (you do not need to provide your name) - Whether you stopped the medication and whether the reaction resolved

What happens after you report: Your report is added to the MHRA's database and analysed alongside other reports to identify signals. You may be contacted for additional information. Reports do not result in any regulatory action against you, and submitting a report does not constitute a formal complaint or legal action against the manufacturer.

Reporting is particularly important for serious or unexpected reactions — including mental health changes — because this is precisely how the semaglutide suicidal ideation signal was identified for investigation in the first place. Collective reporting from patients and clinicians across Europe drove the regulatory review that produced clearer guidance for everyone.

*This article is for educational purposes only. If you are experiencing a mental health crisis, please contact emergency services (999), attend A&E, or call Samaritans on 116 123. Do not adjust your medication without speaking to your prescriber.*