Non-maleficence

Non-maleficence is the ethical principle requiring psychologists and clinicians to avoid causing harm to clients or research participants, and to prevent harm when possible. In AP Psychology, it shows up in both research ethics and the treatment of psychological disorders (Topic 8.4).

Verified for the 2027 AP Psychology examLast updated June 2026

What is Non-maleficence?

Non-maleficence is the "do no harm" rule of psychology. It means a clinician or researcher must avoid actions that could hurt a client or participant, and must actively work to prevent harm from happening. That includes obvious harms (a treatment that makes symptoms worse) and subtler ones (unnecessary distress, breaking trust, or continuing an intervention that clearly isn't working).

Here's the catch that makes it interesting for AP Psych. Some effective treatments involve short-term discomfort. Exposure-based therapy for anxiety or OCD deliberately puts a client face-to-face with what they fear. Non-maleficence doesn't ban discomfort. It bans unnecessary harm. The clinician has to weigh temporary distress against the long-term benefit of recovery, get informed consent, and stop if the harm outweighs the good. That balancing act between avoiding harm and doing good is exactly where exam questions like to live.

Why Non-maleficence matters in AP Psychology

Non-maleficence connects to Topic 8.4 (Bipolar, Depressive, Anxiety, and Obsessive-Compulsive and Related Disorders) in Unit 8, because diagnosing and treating disorders raises real ethical stakes. Labeling someone with a disorder, choosing a therapy, or running an exposure session can all help or harm. The principle also anchors the research ethics you learn early in the course, since every psychological study must protect participants from harm. On the exam, ethics questions reward you for applying the principle to a scenario, not just defining it. If a question describes a clinician treating OCD with exposure and response prevention, you should be able to explain how the clinician honors non-maleficence by minimizing distress, monitoring the client, and keeping the treatment justified by its benefits.

How Non-maleficence connects across the course

Beneficence (Research Methods & Ethics)

Beneficence and non-maleficence are two sides of one coin. Beneficence says actively do good for the client; non-maleficence says avoid doing harm. A clinician needs both, because a treatment that helps but also recklessly damages the client fails the ethical test.

Informed consent (Research Methods & Ethics)

Informed consent is how non-maleficence gets put into practice. When a client agrees to a treatment after learning its risks, like the temporary anxiety spike in exposure therapy, the clinician has made potential harms transparent instead of hidden.

Anxiety Disorders and OCD treatment (Unit 8)

Treating anxiety disorders and OCD often means exposure and response prevention, which intentionally triggers distress. Non-maleficence forces the clinician to keep that distress proportional, consensual, and therapeutic rather than gratuitous.

Experiment design (Research Methods)

Non-maleficence applies to research, not just therapy. Experimenters can't assign participants to conditions likely to cause lasting harm, which is why IRBs review studies and why classic studies like Milgram's are now taught as ethical cautionary tales.

Is Non-maleficence on the AP Psychology exam?

Expect non-maleficence in application-style multiple-choice questions and in ethics-flavored scenario questions. A typical stem describes a clinician or researcher making a decision, then asks which ethical principle is at stake or how the principle should guide the choice. Practice questions ask things like how non-maleficence applies to a clinician treating obsessive-compulsive disorder. The right move is to name the principle, then connect it to the specifics of the scenario, for example explaining that exposure therapy is ethical only when the temporary distress is consented to and outweighed by the expected benefit. No released FRQ has used the term verbatim, but ethics principles are fair game whenever a free-response scenario involves treatment or research with human participants.

Non-maleficence vs Beneficence

These get mixed up constantly because both are about client welfare. Beneficence is the positive duty to actively promote good (provide effective treatment, advocate for the client). Non-maleficence is the negative duty to avoid causing harm (don't use risky or unjustified interventions). Quick test for an MCQ: if the scenario is about helping, it's beneficence; if it's about not hurting, it's non-maleficence.

Key things to remember about Non-maleficence

  • Non-maleficence is the ethical principle that psychologists must avoid causing harm to clients and research participants, often summarized as "do no harm."

  • It is not the same as beneficence, which is the duty to actively do good; non-maleficence is specifically the duty to avoid and prevent harm.

  • Non-maleficence does not ban all discomfort; exposure therapy for anxiety and OCD is ethical when the short-term distress is consensual and outweighed by long-term benefit.

  • The principle applies to both treatment settings (Topic 8.4 disorders) and research settings, where IRBs review studies to protect participants.

  • On the exam, you apply the principle to a scenario, explaining how a specific clinical or research decision avoids or fails to avoid unnecessary harm.

Frequently asked questions about Non-maleficence

What is non-maleficence in AP Psychology?

Non-maleficence is the ethical principle that psychologists and clinicians must avoid harming clients and research participants, and prevent harm when possible. It's the "do no harm" rule that guides both therapy and research.

What's the difference between non-maleficence and beneficence?

Beneficence is the duty to actively do good for a client; non-maleficence is the duty to avoid causing harm. They work together, but exam questions test whether you can tell "help" apart from "don't hurt."

Does exposure therapy violate non-maleficence since it causes anxiety?

No. Non-maleficence prohibits unnecessary harm, not all discomfort. Exposure therapy's temporary anxiety is ethical when the client gives informed consent and the distress is outweighed by the long-term benefit of recovery.

How does non-maleficence apply to treating OCD or anxiety disorders?

A clinician using exposure and response prevention must keep the client's distress proportional and therapeutic, monitor for worsening symptoms, and stop or adjust treatment if it's causing more harm than benefit. That's non-maleficence in action.

Is non-maleficence only about therapy, or does it apply to research too?

It applies to both. In research, non-maleficence means experimenters can't expose participants to lasting harm, which is why studies need ethics review and why studies like Milgram's obedience experiments are criticized today.