How Do Antidepressants Work? Helping Loved Ones with Treatments for Depression
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Antidepressants are among the most commonly prescribed medicines in Australia, and many of the people taking them depend on someone at home to help keep things on track. Handling antidepressant medication comes with questions a product information leaflet does not cover: how these medicines settle into the body, what to expect across the first few weeks, which reactions to flag with the GP, and which ones mean a trip to hospital.
What Are Antidepressants?
Antidepressants are medicines used to treat depression and anxiety disorders including persistent low mood, panic disorder, obsessive compulsive disorder, post-traumatic stress, chronic nerve pain, migraine prevention, and insomnia. They gradually adjust brain chemistry over weeks.
Different antidepressants suit different people. Two people with the same diagnosis may land on very different prescriptions. A doctor’s choice for depression takes into account other health conditions, other medicines already being taken, family history, past responses to medication, pregnancy or breastfeeding, and the person’s own preferences.
Types of Antidepressants
Antidepressants are grouped based on how they adjust brain chemistry. This tells you what to expect for side effects, how strict the rules are around other medicines, and how withdrawal might feel.
Selective serotonin reuptake inhibitors, or SSRIs, are the most commonly prescribed class in Australia. Common generic names include sertraline, escitalopram, fluoxetine, paroxetine, citalopram, and fluvoxamine.
Serotonin and noradrenaline reuptake inhibitors, or SNRIs, include venlafaxine, desvenlafaxine, and duloxetine. Doctors tend to recommend these when depression is more severe or when an SSRI has not helped enough.
Tricyclic antidepressants, or TCAs, include amitriptyline, nortriptyline, clomipramine, imipramine, and doxepin. These are older medicines with a more side effects and a higher risk of overdose.
Atypical antidepressants block brain cells from cleaning up mood chemicals like serotonin. Mirtazapine is sedating and tends to be used when sleep or appetite have been affected. Agomelatine acts on melatonin receptors and helps reset the body clock. Vortioxetine is used for depression in adults where thinking and concentration have been affected.
Monoamine oxidase inhibitors, or MAOIs, such as phenelzine and tranylcypromine, are rarely prescribed among newer antidepressants because of strict food restrictions and the risk of dangerous reactions with other medicines.
How Do Antidepressants Work?
Nerve cells in the brain talk to each other using chemical messengers called neurotransmitters. Three of these messengers, serotonin, noradrenaline, and dopamine, carry signals linked to mood, sleep, attention, appetite, and motivation. In depression and many anxiety disorders not enough of the message gets through.
Most antidepressants step in at the junction between two nerve cells. When a nerve cell releases serotonin or noradrenaline, the same cell usually sweeps the chemical back up a few seconds later so the signal ends. An antidepressant blocks that sweeping-up step, called reuptake, which leaves more of the messenger in the gap between cells and keeps the signal going a little longer.
Brain chemistry is altered within the first few hours after a dose, but relief from the symptoms of depression tends to take two to six weeks. Longer-term adjustments follow the change in chemical levels, such as new connections forming between cells, and it is those adjustments that appear to lift mood.
Common Side Effects of Antidepressants
Most people starting antidepressant drugs notice some side effects. Some fade as the body adjusts; others settle in for the longer haul and may eventually prompt a change of medicine. Possible side effects include:
- Nausea, diarrhoea, and appetite loss.
- Headaches, dry mouth, and mild tremors.
- Sleep can shift towards both insomnia or oversleeping,
- Weight gain
- Reduced interest in sex, trouble reaching orgasm, and trouble with erections or natural lubrication.
- Dizziness , sweating, and a faster heart rate can show up.
Adverse Effects
Some reactions to prescribed antidepressants need more than a note for the next appointment. Quick recognition of the serious ones is the single most useful skill a support person brings to the job.
Serotonin syndrome, or serotonin toxicity, is when serotonin levels climb too high. It is triggered by a dose increase, by starting antidepressants on top of another serotonin-raising medicine, or by an overdose. Warning signs appear within hours and include agitation and confusion, heavy sweating, shivering or muscle twitching, fast heart rate, high temperature, diarrhoea, and rhythmic jerking in the legs. Severe cases can cause seizures and are life-threatening.
Suicidal thoughts can appear or worsen in the first few weeks after starting a new treatment of depression, particularly in people under 25. Anyone starting or switching antidepressants needs close contact in the early weeks.
SSRIs and SNRIs can raise the risk of bleeding, especially when taken with aspirin, ibuprofen, or blood thinners. Easy bruising, nosebleeds, blood in stool, or unusually heavy periods after starting antidepressants are worth raising with the GP.
Falls and low sodium levels are more common in older people with depression, which can cause headaches, nausea, confusion, unsteadiness, and seizures. Allergic reactions to antidepressants are rare but do happen.
Helping Someone Take Antidepressants to Treat Depression and Anxiety
The practical side of helping someone take an antidepressant breaks down into four jobs: getting the dose in, watching for changes, keeping the paperwork straight, and holding the conversation.
Most antidepressants are taken once a day at the same time. A dosage aid, such as a weekly pill organiser or a pharmacist-packed blister pack (Webster-pak), removes the daily guesswork about whether the dose has been taken. Phone alarms, a tick sheet on the fridge, or pairing the dose with an anchor activity such as brushing their teeth all help. A dose missed by a few hours can usually be taken as soon as it is remembered; if it is closer to the next dose, the missed one should be skipped and the schedule resumed, never doubled up.
Track sleep, appetite, energy, mood, and anything new since the last dose in a diary. An up-to-date list of every medicine the person takes, prescription and otherwise, should be brought to every appointment and pharmacy visit. This include vitamins, herbal supplements, and over-the-counter medicines.
Not everyone wants to talk about how the medicine is affecting them, particularly around sex, mood, and suicidal thoughts, but a supportive person can open space for the topic without pushing. Short, direct conversaations tend to do better than long ones, something like “I noticed you seem flatter this week, anything worth mentioning to the GP?”
These hard rules around antidepressants are:
- Never adjust the dose or stop the medicine without the GP’s say-so.
- Never share the medicine with another person, even if they’re on the same one.
- Lock the medication away if anyone in the house is at risk of harming themselves.
- Record every dose change, side effect, and GP conversation.
Your Role Alongside the Medicine
Helping someone take start a course of antidepressants comes with a lot of concerns, but they are easily managed by understanding the medication. It takes time for them to work, and you can be the biggest support of someone you love during those weeks. An accredited medication administration course puts anyone on the same footing as trained carers working in aged care, disability support, and community services, even if they’re just taking care of a loved one at home. Your attention already carries someone through the hardest stretch of antidepressants, and enrolling in medication administration training locks that attention into a framework you can rely on when a bad day turns into a serious one.
FAQs
What Do I Need To Know About Stopping Antidepressants?
Antidepressants need to be tapered over weeks under GP guidance. Stopping them suddenly can bring on withdrawal effects such as dizziness, electric-shock sensations in the head, nausea, insomnia, and a fresh wave of anxiety or low mood. Current Australian guidance is to keep taking antidepressants for at least six months after depression symptoms have settled, and for people with recurrent episodes that period can run to years.
Should You Avoid Alcohol When Using Antidepressants?
Alcohol dampens the effect of antidepressants and can make depression and anxiety harder to lift. Light social drinking is usually tolerated once the person has settled on the medicine.
What Happens If the Antidepressant Does Not Help?
About one in three people do not respond fully to the first antidepressant they are prescribed, and switching to a different medicine is the next step. When depression has not responded to at least two different antidepressants at full dose and full duration, a psychiatrist usually gets involved to recommend newer treatments.
