Mental Health Medications: Side Effects Your Prescriber Should Have Explained

Therapy & Treatment · 3 · March 25, 2026

About 50% of people prescribed antidepressants stop taking them within the first year — and the number one reason isn't that the medication doesn't work. It's side effects that weren't adequately explained upfront. A 2023 study in the British Journal of Psychiatry found that only 37% of patients felt their prescriber had thoroughly discussed potential side effects before starting treatment.

Sexual Dysfunction: The Elephant in the Room

SSRIs cause some degree of sexual dysfunction in 40-65% of users, per a 2022 systematic review in the Journal of Clinical Psychiatry. Reduced libido, difficulty achieving orgasm, and erectile dysfunction are all common. Many prescribers minimize this: "it might affect your sex life a little." A more honest conversation would be: "there's roughly a 50/50 chance this will significantly affect your sexual function, and we have strategies if it does." Strategies include dose reduction, switching to bupropion (which has minimal sexual side effects), adding bupropion to the SSRI, or trying mirtazapine. The problem isn't that solutions don't exist — it's that patients give up before asking.

Weight Gain: Varies Dramatically by Medication

Not all psych medications cause weight gain, but some cause a lot. Mirtazapine averages 2-4 kg in the first year. Paroxetine averages 3-4 kg. Olanzapine (used as augmentation) averages 5-7 kg. Meanwhile, bupropion is weight-neutral or slightly weight-reducing, and fluoxetine tends to be weight-neutral long-term. If weight management is important to you, discuss specific medication options upfront. The data on individual drugs is very clear — there's no reason to be surprised by weight gain when the prescriber could predict it.

Emotional Blunting

About 40-60% of SSRI users report "emotional blunting" — difficulty feeling strong emotions of any kind, positive or negative. A 2023 study in Neuropsychopharmacology confirmed this using behavioral testing, showing that SSRIs reduce emotional reactivity across the spectrum. For severe depression, blunting the worst lows is welcome. But for milder cases, trading depression for feeling "flat" or "numb" isn't always an acceptable trade. This side effect is dose-dependent — reducing the dose often restores emotional range while maintaining antidepressant benefit.

Discontinuation Syndrome

Stopping SSRIs abruptly causes withdrawal-like symptoms in about 56% of patients: dizziness, brain zaps (electric shock sensations), nausea, irritability, and flu-like feelings. Paroxetine and venlafaxine have the highest discontinuation rates. The symptoms are not dangerous but can be extremely unpleasant. Tapering over 4-8 weeks (or longer for paroxetine/venlafaxine) prevents most symptoms. This information should be provided when starting a medication, not discovered when trying to stop.

Key Takeaways

- Sexual dysfunction affects 40-65% of SSRI users — bupropion is an alternative with minimal effects

- Weight gain varies dramatically by medication — ask about specific drugs

- Emotional blunting affects 40-60% of users and is dose-dependent

- Never stop SSRIs abruptly — taper over 4-8 weeks to avoid discontinuation syndrome

Find medication-savvy prescribers through our Smart Flow pathway.