A Yellow Pill

About to take Risperdal?

You’re not alone.  This guide will hopefully help you by explaining what it is used for.  Additionally, it provides a list of the rarest side effects that you may not find elsewhere.

First, what is Risperdal?

Risperdal, generic Risperidone, is an atypical antipsychotic.  It’s “atypical” because it is less likely to cause seizures or permanent movement disorders, than meds which used to be considered “typical.”  And it’s an antipsychotic because its primary use was to treat psychosis associated with schizophrenia.

The full list of conditions it is used for?  Risperdal is used for almost every psychiatric ailment.  That includes autism, ADHD, developmental disorders, schizophrenia, bipolar disorder, depression, OCD, anxiety-disorders, and more.

A better question than asking what it is used for is to ask what it isn’t.

How good is it for these uses? And what about its side effects?

What does it do?

Risperdal is an antagonist to dopamine, D2, and serotonin, 5-HT, receptors.  What that means is that the drug goes into your brain and binds to receptors on cells that are specific to dopamine and serotonin.

This may be important in schizophrenia because elevated levels of dopamine are associated with psychosis.  And it may play a role in depression, because serotonin levels are somehow associated with depression.

We don’t know much beyond that.

Uses of Risperdal


Risperdal is an effective and important part of treating schizophrenia.  While the medications we have are not as effective as they should be, they are much better than nothing.  1/4 to 1/3 of people with schizophrenia do not respond to treatment.

Risperdal works in roughly 57% of those who take it, as opposed to 52% of those who take Haloperidol, an older, typical antipsychotic.  Importantly, Risperdal has less chance of causing movement disorders, and slightly more people continue to use it than Haldol.  It may, however, cause more weight gain.

Bipolar Disorder

The evidence for Risperdal in bipolar disorder is not as good as that for schizophrenia, but seems to generally be positive, albeit not decisively convincing.  As a rule, it is used as an augmentation therapy – in addition to other medications.

One study showed that augmentation of therapy for bipolar with Risperdal lead to a 3 point difference in one scale of depression.  Another showed quicker and stronger response to treatment with Risperdal:  more than 50% responded to combination therapy with another similar medication, 40% responded to the antidepressant alone, and roughly 25% responded to placebo.


Risperdal is sometimes considered as an addition to treatment of depression when it does not respond to therapy by antidepressant alone.  Whether or not this is a good idea really depends on who you talk to.

One study showed that dual therapy increased time to relapse from 80 to 100 days.  So if you are very depressed then go into remission, adding Risperdal might give you an additional 20 days until you become very depressed again.

Not very inspiring.

That said, another study showed very positive response to antidepressant combined with risperdal in treatment resistant depression – so positive that it won’t be repeated here as it might be unrealistic.

Side Effects

At least 10% of people who take Risperdal may experience the following:  Exhaustion, vomiting, increase in hunger, upper respiratory tract infection, urinary incontinence, and more.

Other common side effects include: Anxiety, akathesia, sedation, insomnia, dry mouth, low blood pressure, muscle pain, excessive salivation.

Rare side effects:

Diabetes and/or elevated blood sugar.  Permanent muscle twitches and uncontrollable movements.

Neuroleptic Malignant Syndrome.  This is rare and potentially fatal, and causes fever, muscle stifness and confusion.

Breast tenderness, and even milk secretion.

Very Rare Risperdal Side Effects

  • Fainting.  Risperdal has been reported to cause fainting in a child.  It can do this because it slows down the heart and can rarely interfere with cardiac conduction.
  • Bed wetting.  Several children have been reported to start wetting their beds after using Risperdal, which went away when they stopped.
  • Cerebrospinal shunt malfunction.  Risperdal can cause symptoms that appear to be caused by a cerbrospinal shunt malfunction, such as intercranial pressure, headaches and nausea.  As such, its use in patients with hydrocephalus may be an issue.
  • Night terrors.  Several cases of night terrors have been associated with Risperdal.  A night terror is much like what it sounds – in the middle of the night, lying in bed, you have a extreme panic attack.
  • Priaprism.  We have 17 reports of Risperdal causing priaprism, or a protracted and unpleasantly long erection.
  • Hair loss.
  • Swelling.  Risperdal can interact with other medications to cause swelling of body parts.
  • Rabbit syndrome.  The name for a specific type of motor twitch that, to the doctors observing it, seems amusingly like that of a rabbit.  Not so funny for the patient.



All content on this site is strictly for INFORMATION PURPOSES ONLY. Please consult your doctor for any advice regarding your condition.