Believing in a “chemical imbalance” might keep patients on antidepressants longer

People who view their depression or anxiety as the result of a chemical imbalance tend to use antidepressants for much longer periods than those who see their condition as a reaction to life events. These individuals are also less likely to attempt coming off their medication, even when their ongoing symptoms are mild. The research detailing these patterns was published in the Journal of Affective Disorders.

Since the 1990s, pharmaceutical marketing and educational campaigns have heavily promoted the idea that depression is a biological disease. Many of these campaigns specifically claimed that emotional distress originates from a lack of serotonin in the brain. This medical explanation was originally intended to reduce social stigma and encourage people to seek professional help. Over the past few decades, prescriptions for depression and anxiety have surged in both the United States and the United Kingdom.

Today, long-term prescribing is a primary driver behind the massive increase in continual antidepressant use. In the UK, millions of people take these drugs, and at any given time, half of them have been taking their medication for more than two years. In the US, nearly half of all patients on antidepressants have been taking them for more than five years. While medical guidelines do recommend ongoing treatment for some individuals, health experts estimate that a large portion of long-term users might be taking the medication unnecessarily.

A growing body of modern research has failed to support the original biological theories of depression. Recent systematic reviews of the scientific literature have found no consistent evidence linking depression to abnormal serotonin levels. Despite this shift in scientific understanding, public perception remains heavily influenced by older marketing messages. Survey data from recent years shows that up to 80 percent of the population in Western countries holds onto the chemical imbalance theory.

Mollie Griffin Williams, a researcher at University College London, alongside psychiatrist Joanna Moncrieff and their colleagues, wanted to investigate how these lingering biological beliefs affect modern patients. The researchers suspected that believing a mental illness is a physical brain defect might change how an individual approaches their recovery. They specifically wanted to know if this perspective makes patients more hesitant to stop taking their medication.

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To explore this question, the research team designed a cross-sectional survey for adults attending a public psychological therapy service in the UK. This national program provides free counseling and support for people experiencing common mental health problems like depression, generalized anxiety, and post-traumatic stress disorder. The team contacted patients who had consented to be approached for research and verified their eligibility. A total of 497 people who were either currently taking or had previously taken antidepressants completed the online questionnaire.

The survey asked participants to select the statements that best described their understanding of their original condition. Options included biological explanations, such as a brain illness or a chemical imbalance, as well as environmental explanations, such as a response to life issues. Another set of questions asked participants how they viewed the action of their medication. Here, they could indicate whether they believed the drugs corrected low serotonin, acted as a temporary aid, or served as a bridge to make therapy easier.

The researchers also extracted data from the patients’ medical records to gather an objective measure of their mental health. They looked at the participants’ starting scores on standard clinical questionnaires used to evaluate depression and anxiety. These tools, known as the Patient Health Questionnaire and the Generalized Anxiety Disorder assessment, provide a numerical rating of symptom distress. By comparing these scores, the team could check if differing beliefs were simply a byproduct of how sick the patients actually were.

The survey responses revealed a blend of patient perspectives. About 57 percent of the respondents endorsed at least one statement attributing their condition or their need for medication to a biological cause. At the same time, roughly 66 percent of the participants thought their mental health struggles were a response to difficult life events. This overlap suggests that many people hold mixed views, accepting both medical and environmental explanations for their emotional distress.

When the researchers looked at medication habits, a distinct behavioral pattern emerged. People who held biological beliefs about their mental health had used antidepressants for a median duration of 12 months. In contrast, patients who did not endorse biological explanations had used the drugs for a median of only six months.

The views patients held also corresponded to differing attitudes about the medication’s effectiveness. Individuals in the biological belief group were more likely to report that the drugs had improved their symptoms. They were also much more likely to express that they could not cope with daily life without their antidepressants.

This psychological reliance translated into a lower willingness to stop treatment. Among those with biological beliefs, only about 58 percent had ever attempted to stop taking their medication. In the group lacking these beliefs, nearly 68 percent of patients had tried to come off their antidepressants.

The team checked the clinical assessment scores to ensure these differences were not driven by underlying illness severity. They found no differences in the initial depression or anxiety scores between the two belief groups. The patients holding biological views were not objectively more unwell than the others, meaning their prolonged duration of use was tied to their perspective rather than their pathology.

The researchers also evaluated how these beliefs interacted with drug withdrawal. Patients who attempt to stop taking antidepressants often experience a discontinuation syndrome, which can include dizziness, electric shock sensations in the brain, and emotional swings. In this study, among the people who had tried to quit, holding a biological belief was not associated with experiencing more severe withdrawal symptoms. However, using the medication for a longer period of time was linked to much worse withdrawal effects down the line.

The research team acknowledged several limitations to their methodology. Because the study was a cross-sectional survey, it only captured a snapshot of the participants at a single moment in time. This design cannot prove that biological beliefs directly cause patients to take medication for longer periods. It remains entirely possible that the daily routine of taking a pill gradually shapes a person’s mindset, reinforcing the idea that they suffer from a permanent chemical deficit.

The patient sample also presents a limitation regarding how universally these findings apply. The participants were recruited from a public psychotherapy service, indicating that they were already open to non-medical forms of mental health intervention. This specific demographic might naturally lean more toward treating their condition as a reaction to personal stress compared to the broader population of drug users. Additionally, the evaluations of withdrawal symptoms were based on retrospective self-reports, which can contain memory inaccuracies.

Moving forward, the researchers suggest that reshaping how medical professionals talk about mental health might improve patient outcomes. Because longer drug usage leads to worse withdrawal symptoms, preventing unnecessary long-term reliance is a major public health priority. Future studies will need to test whether explicitly educating patients about the lack of evidence for chemical imbalances helps them safely discontinue their medication. If doctors avoid framing depression as a permanent biological defect, their patients might find it easier to leave their prescriptions behind once they recover from a difficult period in life.

The study, “Beliefs about the biological nature of mental disorders and how they affect antidepressant use and withdrawal,” was authored by Mollie Griffin Williams, Mark Horowitz, James Davies, and Joanna Moncrieff.