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Weight Gain from Antidepressants: Causes and What to Do About It
- Dr Titilayo Akinsola
- Nov 3
- 5 min read
Introduction
Starting antidepressants can bring real relief—but for many people, one of the more frustrating outcomes is unexpected weight gain. It can feel unfair: you’re managing your mood, doing what you need to feel better, yet your body seems to be working against you. At Favor Mental Health we know this is more than “just cosmetic” — weight gain can affect self-esteem, physical health, adherence to treatment, and overall well-being. In this post we’ll dive into why antidepressants can cause weight gain, which medications carry higher risk, how to recognise when it’s happening, and what steps you and your provider can take together.
Why Antidepressants May Cause Weight Gain
There are multiple, overlapping mechanisms. Understanding them helps patients feel less at fault and more empowered to act.
1. Appetite and neurotransmitter effects
Many antidepressants impact neurotransmitters like serotonin, norepinephrine and dopamine, which also regulate appetite, satiety, food reward and metabolism. (Medical News Today)
For example, increased serotonin activity might restore appetite in someone who was previously depressed and eating very little — which might look like “weight gain” but is actually return to normal. (Mayo Clinic)
Some medications have antihistamine or other receptor-blocking effects (for example H1 or 5-HT2C receptors) which can increase hunger and slow metabolism.
2. Metabolic rate, insulin response and energy expenditure
Some antidepressants appear to reduce basal metabolic rate (calories burned at rest), alter insulin sensitivity, and increase fat-storage predisposition — essentially shifting metabolism. (outro.com)
A review found that antidepressant-induced weight gain is associated with insulin resistance, altered leptin/ghrelin signalling, and other metabolic changes.
3. Lifestyle and functional changes
When depression improves, physical activity may still lag (you’re now more mobile, but habits take time). Nutritional habits may shift. Less fatigue may lead to more eating. (Medical News Today)
Some antidepressants cause sedation or fatigue-related side-effects, which could reduce spontaneous movement, further contributing to weight gain.
4. Differential risk by medication class and individual factors
Older drug classes (tricyclics, MAOIs) carry higher weight gain risk than many newer ones.
Some medications appear to have lower risk or even weight-neutral/weight-loss profiles (for example Bupropion) in some individuals.
Personal variables like baseline body mass index, metabolism, diet, physical activity, genetics, and how long you’ve been on medication all influence risk.
Part II. Which Antidepressants Are Higher or Lower Risk?
Higher-risk examples
Some tricyclic antidepressants (TCAs) such as Amitriptyline, Nortriptyline are among the highest risk for weight gain.
Some MAOIs also carry weight gain risk.
Among more commonly prescribed newer drugs, certain SSRIs like Paroxetine appear more likely to lead to weight gain with long-term use. (Medical News Today)
The atypical antidepressant Mirtazapine is noted for increased appetite and weight gain.
Lower-risk or more weight-neutral options
Some SSRIs such as Sertraline or Escitalopram may have less weight gain risk (though not zero).
Bupropion (Wellbutrin) is frequently cited as having a more favourable weight profile (sometimes weight-loss). (Healthline)
Recognising and Tracking Weight Gain — What to Monitor
You and your provider should treat weight changes as a meaningful part of your mental-health plan, not incidental.
Baseline: When starting an antidepressant, record your body weight, waist measurement, appetite, physical activity level, diet pattern and mood symptoms.
Six- to twelve-week check-in: Monitor changes in weight, appetite, hunger levels, changes in clothes/waist size, energy/activity level.
Long-term monitoring: Beyond early weeks, some weight gain emerges gradually over months; a study found that antidepressant users were more likely to gain ≥ 5% body weight over 10 years compared to non-users.
Ask these questions:
Has my appetite increased significantly since starting or changing medication?
Am I eating more, snacking more, or making higher-calorie choices?
Has my activity level dropped or am I more fatigued?
Is the medication causing sedation or sleep disturbance that affects metabolism or movement?
Should we consider switching medication or integrating weight-management strategies?
What to Do About It — Actionable Steps
Here’s how Favor Mental Health recommends managing antidepressant-associated weight gain, in partnership with your clinician.
1. Review medication options
If you are gaining weight and it’s affecting your quality of life or health, it’s valid to talk with your provider about switching to a different antidepressant with lower weight-gain risk, if clinically appropriate.
Never stop or switch medication abruptly without supervision — mood relapse risk and withdrawal risk are real.
Your clinician may consider adding or adjusting adjuncts (though medication changes should always be carefully weighed).
2. Lifestyle interventions (early and ongoing)
Nutrition: Focus on whole foods, fibre, lean protein, low-glycaemic carbs, reduce high-sugar snacks that trigger appetite/insulin spikes.
Physical activity: Regular moderate-to-vigorous exercise (aerobic + resistance) supports metabolism and helps offset weight gain.
Sleep hygiene: Poor sleep disrupts appetite/hormone regulation (leptin/ghrelin) and increases weight-gain risk.
Monitor and adapt: Use a food/exercise/weight journal to spot patterns. For example, if you notice you’re hungrier in evenings, adjust meal timing or protein content.
At Favor we incorporate a metabolic-aware component into the mental-health treatment plan — because mood + body = recovery.
3. Supportive measures & accountability
Regular follow-ups: We schedule reviews specifically around weight/physical health as well as mood.
Collaborate with other providers: If weight gain is significant, a referral to nutritionist, endocrinologist or other specialist may be appropriate.
Be kind to yourself: Weight gain on medication is not a moral failing. Recognising it early and acting reduces the risk of resentment, non-adherence, and feeling “this isn’t working”.
4. When to escalate intervention
If you're gaining > 5 % of body weight in a relatively short period (months), especially if metabolic markers (blood sugar, lipids) are changing.
If weight gain undermines your mood improvement (e.g., increased self-criticism, body-image distress, social withdrawal).
If you have compounding risk factors (family history of diabetes, metabolic syndrome, sedentary lifestyle) thus weight gain may impact physical health long term.
Why This Matters for Your Recovery
Weight gain can reduce self-esteem, increase shame or guilt, and ironically undermine the mood improvement the antidepressant brought.
It can contribute to physical-health complications (metabolic syndrome, type 2 diabetes, cardiovascular risk).
If weight gain becomes intolerable, some people stop their antidepressant prematurely — risking relapse of depression. Addressing this proactively protects both your mental and physical health.
At Favor Mental Health, we believe your treatment plan must honour your whole self: mind, body, movement, metabolism, and life purpose. Weight gain is not just a side-effect — it’s a signal we need to adapt the plan.
How Favor Mental Health Can Help You
If you recognise any of the following, it’s a good moment to take action:
You’ve started an antidepressant (or been on one for a while) and have noticed unexpected weight gain, increased appetite/cravings or reduced activity.
You’re worried about body-image, physical-health or feel the weight gain is undermining your recovery.
You’d like a holistic review that includes both your mental-health medication plan and metabolic/physical-health strategy.
Schedule a paid consultation with Favor Mental Health today. We will:
Review your medication, mood symptoms, lifestyle, weight/health history and appetite/activity patterns
Map a dual-track plan: preserving your mental-health gains while addressing weight/physical health through medication review + lifestyle intervention
Provide ongoing monitoring and support — you’re not alone in this.
Your health is multidimensional. Your recovery should reflect that. Let’s design a treatment map that honours both your mind and your body.
Closing
Weight gain from antidepressants is not uncommon — but it doesn’t have to derail your recovery or sense of self. With awareness, timing, and a collaborative plan, you can manage it proactively. At Favor Mental Health we believe in nuanced care: you are more than your medication, your weight, or your mood. You are a person with a life, values and purpose. Let’s move forward intentionally — with respect for your mental-health journey and your physical-health goals.