What the Evidence Really Says
When it comes to treating depression, one of the most common questions clients ask is: “Do I need medication, therapy, or both?” It is a fair question — and the answer is more nuanced than a simple yes or no. Decades of research now offer us genuine clarity on which approach works best, for whom, and under what circumstances. This article explores the role of antidepressants in supporting mental health treatment, how they work in plain language, and what the science tells us about the best path forward for lasting recovery.
Understanding Depression as a Brain-Body Experience
Before exploring treatment options, it helps to understand that depression is not simply “feeling sad” or a sign of personal weakness. Depression is a complex condition involving changes in brain chemistry, neural circuitry, and how different regions of the brain communicate with one another. It affects sleep, appetite, energy, concentration, and the capacity for joy — and it is one of the most treatable conditions in mental health.
When we understand depression as something that affects both the brain and behaviour, it becomes easier to see why different treatments — or combinations of them — can work in different ways.
How Do Antidepressants Work? A Plain-Language Explanation
The most commonly prescribed antidepressants today are a class of medications called SSRIs — Selective Serotonin Reuptake Inhibitors. Common examples include fluoxetine (Prozac), sertraline (Zoloft), and escitalopram (Lexapro).
Think of your brain as a vast messaging network. Billions of nerve cells (neurons) communicate with each other by releasing chemical messengers called neurotransmitters into tiny gaps between cells, called synapses. One key neurotransmitter involved in mood, motivation, and emotional regulation is serotonin.
In a healthy brain, serotonin is released into the synapse, delivers its message to the receiving neuron, and is then “vacuumed back up” into the original cell for reuse — a process called reuptake. In depression, this communication system can become dysregulated, with insufficient serotonin activity at the synapse.
SSRIs work by blocking that vacuum (the reuptake transporter), allowing serotonin to remain in the synapse longer and keep delivering its message. More serotonin activity in the right places supports improved mood, emotional steadiness, and motivation.
It is important to note that this is a simplified explanation. Scientists now understand the brain is far more complex — antidepressants appear to trigger cascading changes in gene expression and brain plasticity over weeks. This is why most people do not feel the full effect for four to six weeks after starting medication.
Antidepressants are not “happy pills.” They do not create artificial euphoria. Rather, they tend to lift the floor — reducing the heaviness and restoring enough neurological stability that a person can begin to engage meaningfully with their life and, crucially, with therapy
What Does the Research Tell Us?
Antidepressants Alone
Antidepressants are clinically effective, particularly for moderate-to-severe depression. A landmark meta-analysis of 54 double-blind, placebo-controlled studies (9,268 patients) found continuation antidepressant treatment produced a robust reduction in relapse — with an odds ratio of 0.35, meaning the risk of relapse was dramatically lower for those who remained on medication compared to those who stopped.
Pooled data from 31 randomized trials found that continuing antidepressants reduced the odds of relapse by approximately 70%, with an average relapse rate of 41% on placebo compared to just 18% for those on active treatment. Over a one-year maintenance period, active drug treatment showed a relapse rate of 23% versus 51% for placebo.
However, antidepressants alone carry a significant limitation: they treat symptoms but do not teach new ways of thinking, processing emotions, or coping with life’s challenges. When medication is eventually discontinued without accompanying skills, relapse risk rises considerably.
Therapy Alone
Psychotherapy — particularly Cognitive Behavioural Therapy (CBT) and Interpersonal Therapy (IPT) — has strong evidence as a standalone treatment, especially for mild-to-moderate depression. The American College of Physicians’ 2023 clinical guidelines recommend CBT monotherapy as the preferred initial treatment for mild major depressive disorder.
Psychotherapy alone builds durable cognitive and emotional skills that belong to the client long after treatment ends. A compelling 2024 meta-analysis found that psychotherapy-only treatment was actually stronger than combined treatment in decreasing the likelihood of serious adverse events, particularly for children and adolescents.
For mild depression, research consistently shows an excellent chance of meaningful recovery with therapy alone. However, for moderate-to-severe presentations, therapy without medication may be slower to take effect — particularly when a client lacks the neurological or motivational capacity to fully engage in the work.
The Combination Approach: Strongest Evidence
When it comes to moderate-to-severe depression, the research overwhelmingly supports combining antidepressants with psychotherapy as the most effective approach.
A comprehensive network meta-analysis of 101 randomised controlled trials involving 11,910 patients found that combined treatment was significantly more effective than either psychotherapy alone (RR=1.27) or pharmacotherapy alone (RR=1.25). Importantly, no significant difference was found between psychotherapy alone and pharmacotherapy alone when compared head-to-head — suggesting both are valid, but neither is optimal on its own for more complex presentations.
A separate meta-analysis of 52 randomized trials (3,623 patients) found the effect of combined treatment over medication alone was a Hedges’ g of 0.43 — a clinically meaningful difference — corresponding to a number needed to treat (NNT) of just 4.20. For every four people treated with combination therapy instead of medication alone, one additional person achieves recovery who would not have otherwise.
Long-term outcomes are particularly striking. A classic three-year study found that 80% of those receiving both monthly interpersonal therapy and antidepressant medication avoided recurrence of major depression, compared to 57% for medication alone, 36% for therapy alone, and 10% for placebo.
Matching Treatment to the Individual
Evidence-based treatment is not one-size-fits-all. The best approach depends on several factors:
- Severity: Mild depression may respond well to therapy alone. Moderate-to-severe depression is best approached with combination treatment, or with medication to stabilise the person enough to engage in therapy.
- History: Individuals with recurrent depression (two or more prior episodes) benefit significantly from longer-term maintenance strategies, often including continued medication.
- Preference: Mismatched treatment preferences are associated with higher dropout, poorer therapeutic alliance, and worse outcomes. Honouring client preferences is clinically important.
- Access: Where psychotherapy is not immediately accessible, antidepressants provide a meaningful bridge and should be paired with therapy as soon as possible.
- Age: Psychotherapy should be prioritised for children and adolescents at high risk, while combined treatment is preferred for high-risk adults.
Antidepressants as a Bridge, Not a Destination
One of the most useful ways to think about antidepressants in a therapy context is as a bridge rather than a destination. For many clients, depression strips away the very energy, motivation, and cognitive clarity needed to benefit from psychological work. Concentration fades. Sleep is disrupted. The capacity to identify patterns in thinking, or to practice new skills, diminishes.
Antidepressants, when effective, can restore enough neurological stability that the client can show up — mentally and emotionally — to do the deeper work of therapy.
Just as a person with a broken leg might need a cast before they can engage in physiotherapy, some individuals need neurochemical stabilisation before cognitive and emotional restructuring becomes accessible. This is not dependency — it is intelligent, evidence-informed staging of treatment.
A Note on Starting and Stopping Medication
Decisions about whether to start, continue, or taper antidepressants should always be made collaboratively with a prescribing doctor. Abrupt discontinuation can trigger withdrawal-like effects and significantly increases relapse risk. Research consistently recommends maintaining effective antidepressant doses for at least six to twelve months after recovery from an acute episode, with longer maintenance for those with recurrent presentations.
Tapering antidepressants gradually while concurrently engaging in CBT has been shown to reduce the risk of relapse during medication discontinuation — another compelling reason to combine both modalities.
The Feel Good Psychology Perspective
At Feel Good Psychology & Counselling, we believe in meeting each client where they are, and supporting evidence-informed decisions that honour both the science and the individual. Antidepressants are not the enemy of good therapy — for many clients, they are the foundation that makes meaningful therapeutic progress possible.
The research is clear: for mild depression, therapy alone is often sufficient and highly effective. For moderate-to-severe depression, combination treatment produces the strongest outcomes, the lowest relapse rates, and the most durable recovery. And for those for whom therapy is not yet accessible, antidepressants offer a vital and clinically meaningful intervention in their own right.
Whatever path is right for you, the most important first step is reaching out. Recovery is possible — and you do not have to navigate it alone.