I want to start with the two most damaging myths about mental health medication.
The first: that antidepressants are "happy pills" that make you artificially cheerful, numb your emotions, and change your personality. This is not how they work.
The second: that taking medication for mental health is a sign of weakness, an easy way out, or evidence that your faith is insufficient. This view causes genuine suffering. It keeps people in pain when effective treatment is available.
The reality is more nuanced than either myth. Mental health medications are useful tools with real effects, real limitations, and real side effects — all of which you deserve to understand clearly before you decide whether to take them.
SSRIs — the most commonly prescribed antidepressants
SSRIs (Selective Serotonin Reuptake Inhibitors) are the first-line medication for depression and most anxiety disorders. Common SSRIs prescribed in the UK:
- Sertraline (Zoloft) — most commonly prescribed, good evidence in pregnancy
- Fluoxetine (Prozac) — longer-acting, useful if adherence is variable
- Citalopram and escitalopram — clean side effect profiles
- Paroxetine — effective but more discontinuation effects
What they actually do: SSRIs prevent the reabsorption (reuptake) of serotonin in the synapse between neurons, increasing the availability of serotonin. However — and this is important — the "chemical imbalance" theory of depression (that depression is simply caused by low serotonin) is an oversimplification that has been significantly challenged by recent research. SSRIs work for many people, but exactly why they work is more complex than the serotonin story suggests.
What they do not do: They do not make you happy. They do not numb emotions. They do not cause personality changes in most people. What most people describe is that the medication reduces the intensity and frequency of depressive episodes — the floor comes up, not a false ceiling that prevents genuine emotion.
The 4–6 week delay: This is the most important practical point about SSRIs. They do not work immediately. The therapeutic effect builds over 4–6 weeks. Many people stop the medication in the first 2 weeks because they feel it is not working — and miss the therapeutic window entirely.
Side effects in the first 2 weeks: Nausea, headache, increased anxiety, disturbed sleep, and sexual dysfunction are common early side effects. Most resolve after 2 weeks. The sexual dysfunction (reduced libido, delayed orgasm) can persist — this is the most common reason for discontinuing SSRIs and should be discussed with your prescriber, as alternatives exist.
Discontinuation: SSRIs should not be stopped abruptly. Stopping suddenly can cause discontinuation syndrome — flu-like symptoms, dizziness, sensory disturbances ("brain zaps"), irritability. Always taper under medical guidance.
SNRIs — the close relatives
SNRIs (Serotonin-Noradrenaline Reuptake Inhibitors) work on both serotonin and noradrenaline. Common examples: venlafaxine (Effexor), duloxetine (Cymbalta).
They have similar effectiveness to SSRIs for depression and anxiety but can have more pronounced discontinuation effects (venlafaxine in particular). Duloxetine has good evidence for both depression and chronic pain — making it a consideration when both are present.
Case study: Adaeze's SSRI experience
Adaeze, 31, came to see me with moderate depression following a difficult year — job loss, relationship breakdown, and the death of her father in Nigeria which she could not travel for. She was reluctant to try medication — her church community had expressed the view that depression was a spiritual problem.
I explained what sertraline actually does and does not do. I explained the 4–6 week timeline. I told her the most common side effects. I also told her that medication was not a substitute for addressing grief and circumstance — but that it could lift the floor enough for her to engage with those things.
She started 50mg sertraline. Week 1: nausea, poor sleep, increased anxiety — she called me worried. I reassured her this was expected and temporary. Week 3: nausea resolved. Week 6: "I feel like I can think again. The sadness is still there but it's not crushing."
She used the medication as a bridge — 8 months of sertraline, concurrent CBT, and gradual life rebuilding. She tapered off sertraline at month 9.
"I still had all the same problems when I started the medication," she told me. "But I had enough brain capacity back to start dealing with them."
Antipsychotics — widely misunderstood
Antipsychotics are prescribed for schizophrenia, bipolar disorder, severe depression with psychotic features, and increasingly as augmentation for treatment-resistant depression and anxiety. They are also used off-label for insomnia and agitation.
First-generation (typical) antipsychotics: Haloperidol, chlorpromazine. Effective but significant side effects including extrapyramidal effects (movement disorders, tardive dyskinesia with long-term use).
Second-generation (atypical) antipsychotics: Olanzapine, quetiapine, risperidone, aripiprazole, clozapine. Generally better tolerated for movement side effects but significant metabolic side effects — weight gain, raised blood sugar, raised cholesterol — are common and clinically important.
What antipsychotics actually do: They primarily block dopamine receptors (D2 receptors). In psychosis, this reduces the intensity of positive symptoms — hallucinations and delusions. They do not cure schizophrenia but they significantly reduce the frequency and severity of psychotic episodes in most people.
The weight gain issue: Olanzapine and clozapine in particular cause significant weight gain in many people — sometimes 10–20kg. This is not a lifestyle failure. It is a pharmacological effect on appetite regulation and metabolism. If you are on an antipsychotic and gaining weight despite reasonable diet, tell your prescriber. Switching to aripiprazole or another metabolically neutral agent may be appropriate.
Mood stabilisers
Used primarily in bipolar disorder. Lithium is the gold standard with the strongest evidence for preventing both manic and depressive episodes. It also has significant evidence for reducing suicide risk — uniquely among psychiatric medications.
Lithium has a narrow therapeutic window — the difference between a therapeutic and toxic dose is small. Regular blood tests (lithium levels, kidney function, thyroid function) are essential and non-negotiable.
Valproate (sodium valproate) is also used as a mood stabiliser but is absolutely contraindicated in pregnancy and in women who could become pregnant due to severe teratogenic risk. If you are a woman of childbearing potential on valproate, discuss this with your doctor.
Benzodiazepines — the short-term solution that becomes a long-term problem
Diazepam (Valium), lorazepam, clonazepam. Effective for acute anxiety within minutes — genuinely useful for short-term crisis management. However:
- Tolerance develops within weeks
- Dependency is common with regular use beyond 2–4 weeks
- Withdrawal can be medically dangerous (unlike alcohol, benzodiazepine withdrawal can cause seizures)
- Not appropriate for chronic anxiety — CBT and SSRIs have superior long-term evidence
If you have been on benzodiazepines for more than a few weeks and want to stop, do not stop abruptly. A gradual taper under medical supervision is essential.
Questions to ask your prescriber
Before starting any mental health medication:
- What is this medication for and how does it work?
- When will I start to feel the effects?
- What are the most common side effects and how long do they last?
- What should I do if I experience [specific side effect]?
- How long will I need to take this medication?
- How do I stop it when the time comes?
You are entitled to these answers. A 10-minute GP appointment is not enough time to have this conversation properly — ask for a longer appointment if needed.
Sources: NICE Clinical Guideline CG90 — Depression in Adults (2009, updated 2022); NICE Clinical Guideline CG185 — Bipolar Disorder (2014, updated 2023); Cipriani A et al, The Lancet 2018 (antidepressant comparative effectiveness); Moncrieff J et al, Molecular Psychiatry 2022 (serotonin hypothesis review); Taylor D et al, The Maudsley Prescribing Guidelines in Psychiatry, 14th edition.
