AQA Clinical Psychology and Mental Health: Must Know, Should Know and Could Know Research Studies

The new Clinical Psychology and Mental Health topic is part of Paper 1 in the updated AQA A-level Psychology specification, with first A-level assessment in 2027. Students must understand definitions of mental health and the characteristics, explanations and treatments of phobias, depression and obsessive-compulsive disorder (OCD).

However, knowing the theories is only part of the challenge. To produce effective AO3, students also need research evidence that can support or challenge those theories and treatments.

This guide organises 13 useful pieces of research into three levels:

• Must Know – the most useful evidence to learn first.

• Should Know – additional research that can strengthen evaluation.

• Could Know – evidence that can add depth, sophistication or a counterargument.

These categories are revision priorities rather than official AQA categories. AQA does not prescribe this list of studies. Students could use other relevant and accurately described research. The topic content itself is set out in the updated AQA specification.

It is also important to remember that Beck’s negative triad and Ellis’s ABC model are named cognitive explanations, not individual research studies. Students must learn both as AO1, but they have not been included in this research-study list.

Must Know studies

1. Watson and Rayner (1920): Little Albert

Watson and Rayner investigated whether an emotional response could be learned through classical conditioning. A young child known as Little Albert was initially unafraid of a white rat. The researchers repeatedly presented the rat alongside a frightening loud noise. Albert subsequently showed fear when the rat was presented without the noise, and his fear appeared to generalise to some other furry objects.

This study can be used to support the acquisition stage of the two-process model, because it demonstrates how a previously neutral stimulus may become associated with fear. However, it was a study of one child, the procedure was not standardised to modern research standards, and there are serious ethical concerns. It therefore provides vivid but limited evidence for explaining the development of phobias. The original study was published as Conditioned Emotional Reactions in 1920. (Watson and Rayner publication record)

Exam use: The study supports classical conditioning as a possible explanation for the acquisition of a phobia, but the case-study evidence cannot establish that all phobias develop in this way.

2. Gilroy et al. (2003): graded exposure for spider phobia

Gilroy and colleagues followed people who had received three 45-minute sessions of either live graded exposure, computer-aided vicarious exposure or progressive muscle relaxation for spider phobia. Forty-two of the original 45 participants were assessed at an average follow-up of 33 months. Improvements were found across several measures, although the interaction between treatment group and time was not statistically significant. (Gilroy et al., 2003)

The study is relevant to systematic desensitisation because live graded exposure is a central element of that treatment. However, it should not be described as a straightforward test of the complete systematic-desensitisation procedure: the live-exposure condition was compared with other interventions, and the long-term differences between groups were not clear.

Exam use: The findings suggest that exposure-based treatments can produce lasting improvements, but they do not isolate precisely which component caused the improvement.

3. March et al. (2007): CBT and fluoxetine for depression

The Treatment for Adolescents with Depression Study compared cognitive behavioural therapy (CBT), the antidepressant fluoxetine, and a combination of the two. At 18 weeks, the combined treatment had an 85% response rate, compared with 69% for fluoxetine and 65% for CBT. By 36 weeks, response rates were 86% for combined treatment and 81% for each treatment used alone. (March et al., 2007)

This provides evidence that CBT is an effective treatment for depression and that combining psychological and biological treatments may produce faster improvement. The study focused on adolescents, however, so its findings cannot automatically be generalised to all adults with depression.

Exam use: March et al. support the effectiveness of CBT, particularly when it is combined with antidepressant medication.

4. Nestadt et al. (2000): a family study of OCD

Nestadt and colleagues compared 80 people with OCD and their first-degree relatives with 73 community controls and their relatives. In total, 343 relatives of the OCD group and 300 relatives of the control group were assessed using structured procedures. The researchers found familial aggregation of OCD: the disorder was more common among the first-degree relatives of people with OCD. (Nestadt et al., 2000)

This supports a genetic contribution to OCD. Nevertheless, family members share environments as well as genes, so a family study cannot by itself show that the association is entirely genetic.

Exam use: The increased risk among first-degree relatives supports a genetic explanation, but shared family experiences provide an alternative explanation.

5. Soomro et al. (2008): SSRIs for OCD

Soomro and colleagues reviewed 17 studies involving 3,097 adults with OCD. Across the studies, selective serotonin reuptake inhibitors (SSRIs) reduced OCD symptoms more effectively than placebos over six to 13 weeks. In the studies measuring clinical response, people receiving SSRIs were almost twice as likely to respond as those receiving a placebo. Adverse effects were generally more common with SSRIs, and the review could not establish their longer-term effectiveness. (Soomro et al., 2008)

The findings support the effectiveness of drug therapy for OCD and are consistent with serotonin being involved in the disorder. However, successful treatment does not necessarily prove that low serotonin caused OCD in the first place.

Exam use: SSRIs appear more effective than placebo in the short term, although side effects and uncertainty about long-term outcomes must be considered.

Should Know studies

6. Öst (1989): one-session exposure treatment

Öst reported the outcomes of an intensive one-session treatment for 20 people with specific phobias. Treatment lasted an average of 2.1 hours and combined prolonged in-vivo exposure with modelling. At a follow-up averaging four years, 90% of the participants were described as much improved or completely recovered. (Öst, 1989)

This is often used as evidence for the effectiveness of intensive exposure or flooding. It is important to describe it accurately: the treatment combined exposure with modelling, so the results cannot be attributed to flooding alone. The series also had only 20 patients and did not use a randomised control group.

Exam use: The study suggests that intensive exposure can be rapid and long-lasting, but the mixed treatment and limited design make it difficult to establish cause and effect.

7. David et al. (2008): psychological therapy and medication for depression

David and colleagues randomly allocated 170 outpatients with major depressive disorder to 14 weeks of rational emotive behaviour therapy (REBT), cognitive therapy or fluoxetine. Immediately after treatment, there were no significant differences between the three conditions. At the six-month follow-up, REBT showed a significantly larger effect than medication on one measure, while the advantage for cognitive therapy was not statistically significant. (David et al., 2008)

The study supports the view that psychological therapies can be at least as effective as medication and may have lasting benefits. However, it would be inaccurate to claim simply that CBT was definitively superior to medication in every analysis.

Exam use: Psychological and drug treatments produced similar immediate outcomes, with some evidence of a longer-term advantage for REBT.

8. Lewis (1936): family patterns in obsessional illness

Lewis’s early clinical work, Problems of Obsessional Illness, described patterns within families of people experiencing obsessional symptoms. It is often used as early support for the claim that OCD runs in families. (Lewis, 1936)

The evidence has historical value, but diagnostic criteria, research methods and standards of reporting have changed considerably since 1936. It should therefore be used cautiously and alongside more systematic evidence such as Nestadt et al.

Exam use: Lewis provides early support for familial transmission, but the age and limited methodological detail of the evidence reduce the strength of any genetic conclusion.

9. Menzies et al. (2007): neural evidence for OCD

Menzies and colleagues reviewed neuroimaging and neuropsychological research into OCD and also conducted a quantitative meta-analysis of functional MRI findings. They reported consistent abnormalities involving orbitofronto-striatal circuits, while noting that findings across studies were not entirely consistent and that other brain areas may also be involved. (Menzies et al., 2007)

This supports a neural explanation of OCD, particularly the involvement of the orbitofrontal cortex and connected circuits. However, brain-imaging evidence is usually correlational. Neural differences could contribute to OCD, result from the disorder, or reflect another variable.

Exam use: The review supports orbitofronto-striatal involvement but does not prove that neural abnormalities cause OCD.

Could Know studies

10. Choy et al. (2007): review of treatments for specific phobias

Choy, Fyer and Lipsitz reviewed research published between 1960 and 2005 on treatments for specific phobias, including in-vivo exposure, virtual-reality treatment and cognitive therapy. The review concluded that exposure-based approaches had the strongest evidence base. (Choy et al., 2007)

This strengthens the argument that behavioural treatments can be effective. Because it was a review of different studies, treatments and phobia types, variation between the included research makes a single simple conclusion more difficult.

Exam use: The wider evidence base supports exposure treatments, although effectiveness may vary according to the procedure and the type of phobia.

11. Cuijpers et al. (2013): meta-analysis of CBT for depression

Cuijpers and colleagues combined 115 studies of CBT for adult depression. CBT produced a substantial overall effect, but the estimated effect became smaller when publication bias was taken into account. Higher-quality studies also reported smaller effects than lower-quality studies. (Cuijpers et al., 2013)

This provides both support and a useful counterargument. CBT is effective, but its benefits may have been exaggerated if unsuccessful or less impressive studies were less likely to be published.

Exam use: The large evidence base supports CBT, while evidence of publication bias encourages a more cautious conclusion about the size of its effect.

12. Taylor (2013): candidate genes for OCD

Taylor conducted a meta-analysis of genetic-association research into OCD. The review identified 230 polymorphisms across 113 studies and found associations with several serotonin-related and other genetic variants. Most individual associations were small, supporting the view that OCD is polygenic rather than being caused by one particular gene. (Taylor, 2013)

The findings strengthen the genetic explanation while also showing why searches for a single “OCD gene” are unlikely to succeed. The modest and sometimes inconsistent associations suggest that genes probably interact with one another and with environmental influences.

Exam use: Taylor supports a polygenic explanation in which several genes each make a small contribution to vulnerability.

13. Cromer et al. (2007): traumatic life events and OCD

Cromer, Schmidt and Murphy studied 265 people diagnosed with OCD. Fifty-four per cent reported at least one traumatic life event, and experiencing one or more such events was associated with more severe OCD symptoms, even after several relevant variables were controlled. (Cromer et al., 2007)

This challenges a purely biological account by showing that environmental experiences are associated with the severity of OCD. The study was correlational, however, so it cannot establish that trauma caused the OCD symptoms. Recall of past events may also have been affected by participants’ current symptoms.

Exam use: The findings support a diathesis-stress account in which biological vulnerability may interact with traumatic or stressful experiences.

How many studies should an AQA Psychology student learn?

Students do not need to memorise every detail of all 13 studies. A more effective approach is to learn a small number very securely and then add further evidence when the core material is confident.

For each study, aim to remember:

1. Who conducted it and when.

2. What the researchers did.

3. The key finding.

4. Which explanation or treatment it supports or challenges.

5. One limitation or alternative interpretation.

A study should never be dropped into an essay without explanation. The student must make the link back to the question clear. For example:

Research support for drug therapy comes from Soomro et al. (2008), who found that SSRIs reduced OCD symptoms more effectively than placebos. This suggests that SSRIs are an effective treatment. However, treatment effectiveness does not demonstrate that low serotonin originally caused OCD, so the evidence supports the therapy more directly than the biological explanation.

That final sentence is what turns remembered research into developed AO3.

Final revision advice

Start with the five Must Know studies and practise applying each one to an exam question. Once those are secure, use the Should Know and Could Know evidence to introduce greater range, methodological analysis and counterarguments.

Above all, prioritise accurate explanation over the number of researchers named. One well-developed and correctly linked study is more valuable than several names listed without analysis.

The Biggest Mistake A Level Psychology Students Make in Obedience Questions (And How to Avoid It)

If you're studying A Level Psychology, there's one topic that many students find difficult: obedience.

After more than 25 years of teaching Psychology and working as an AQA examiner, I've noticed the same pattern year after year. Students often know Milgram's study in great detail, yet still fail to achieve the marks they deserve.

The reason usually isn't a lack of knowledge. It's because they don't know how to use that knowledge effectively in the exam.

Mistake 1: Writing Everything You Know About Milgram

Many students believe that the more they write about Milgram's original experiment, the better their answer will be.

Unfortunately, that isn't how A Level Psychology is assessed.

Examiners reward students who answer the specific question that has been asked. A concise, well-focused answer that directly addresses the question will always score more highly than pages of irrelevant detail.

Before you begin writing, ask yourself:

What is this question actually asking me to explain or evaluate?

Mistake 2: Confusing Explanation with Evaluation

This is probably the biggest mistake I see as an examiner.

Many students think they are evaluating when they are actually explaining.

For example, a student might write:

"Participants were less likely to obey when they were closer to the learner because they felt more responsible for the consequences of their actions."

This is a good explanation of why obedience fell, but it is not evaluation. It demonstrates knowledge of the theory.

Evaluation goes one step further. It asks whether the evidence is convincing, whether there are limitations, or what the findings tell us about obedience.

For example:

"Although proximity reduced obedience from 65% to 40%, a substantial proportion of participants still administered the maximum 450-volt shock. This suggests that proximity alone cannot explain obedience and that other situational factors, such as the legitimacy of the authority figure, also influence whether people obey."

Notice the difference. Rather than simply explaining the findings, this paragraph considers what they mean.

The Three Situational Variables Every Student Must Know

Milgram investigated several situational variables that influenced obedience. These appear regularly in short-answer, application and essay questions.

Proximity

When the teacher and learner were placed in the same room, obedience fell from 65% to 40%. Although this reduction was substantial, many participants still obeyed to the maximum 450-volt shock. This suggests that being physically closer to the victim increases feelings of personal responsibility, making obedience less likely, but it does not eliminate obedience altogether.

Location

When Milgram moved the experiment from the prestigious surroundings of Yale University to a run-down office building, obedience fell to 47.5%. This suggests that people are more likely to obey when authority is associated with a respected institution, increasing its perceived legitimacy.

Uniform

When the experimenter was replaced by an ordinary member of the public rather than someone wearing a laboratory coat, obedience dropped to 20%. This demonstrates the powerful influence of symbols of legitimate authority on obedient behaviour.

Looking for the Pattern

One of the best ways to impress an examiner is to look beyond individual findings and identify the overall pattern.

Although proximity, location and uniform all reduced obedience, none of these situational variables eliminated obedience completely. Many participants still obeyed to the maximum 450-volt shock.

However, two of Milgram's variations produced a striking result.

When participants were allowed to choose the shock level themselves, none administered the maximum 450-volt shock. Likewise, when two experimenters gave conflicting instructions, obedience to the maximum shock also fell to 0%.

What do these two variations have in common?

In both cases, participants could no longer simply follow the instructions of a clear, legitimate authority figure. They had to make their own decision, or they were faced with conflicting commands. As a result, they could no longer displace responsibility onto the experimenter.

This pattern provides strong support for Milgram's agentic state explanation. People are most likely to obey when they perceive that responsibility lies with a legitimate authority figure. When personal responsibility increases, or when authority becomes unclear, obedience is much less likely.

Examiner's Tip

One of the easiest ways to improve your marks is to ask yourself one simple question every time you write an evaluation point:

"So what?"

What does this evidence actually tell us?

Does it support the explanation?

Does it challenge it?

Does it suggest the explanation only works under certain conditions?

Adding just one sentence that explains the significance of the evidence can often move an answer into a higher mark band.

Remember:

• AO1 explains what happened and why.

• AO3 judges the quality, importance or implications of the evidence.

Knowing the difference between these assessment objectives is one of the fastest ways to improve your exam performance.

Try This Exam Question

A manager in a large company instructs an employee to work unpaid overtime. Although the employee believes this is unfair, they agree because the manager is wearing company uniform and is known to hold a senior position.

Using your knowledge of situational variables affecting obedience, explain the employee's behaviour. (8 marks)

Before writing your answer, underline the clues in the scenario.

In this example, the references to the manager's uniform and senior position should immediately make you think about legitimate authority and the situational variables that influence obedience.

The strongest answers don't simply describe Milgram's research—they apply it directly to the scenario.

Final Thoughts

Success in A Level Psychology isn't about memorising more information than everyone else.

It's about understanding how psychological research fits together, applying evidence to unfamiliar scenarios and knowing when the examiner expects explanation rather than evaluation.

As an experienced AQA examiner and Psychology teacher, I help students develop these skills through personalised one-to-one tuition. Lessons focus not only on learning the content, but also on mastering AO1, AO2 and AO3 so students can approach their exams with confidence.

If you're looking for support with A Level Psychology or would like to find out more about one-to-one tuition, I'd be delighted to help.

Different Types of Validity (AQA A-Level Psychology 2027)

What is validity?

Validity refers to whether a test, measure or investigation measures what it is intended to measure.

Face validity

Definition
Face validity is the extent to which a questionnaire, test or measure appears (on the face of it) to be measuring what it claims to measure.

Example
A psychologist develops a questionnaire to measure social anxiety. A panel of experienced psychologists reviews the questions and agrees that they appear to measure social anxiety. The questionnaire therefore has good face validity.

How is it assessed?
By asking experts or members of the target population whether the measure appears to assess the intended behaviour.

How can it be improved?

• Pilot the questionnaire.

• Ask experts to review the items.

• Rewrite or remove ambiguous questions.

Concurrent validity

Definition
Concurrent validity is the extent to which a psychological measure relates to an existing similar measure. It is assessed by comparing a new measure with one that has already been shown to be valid.

Example
A psychologist develops a new questionnaire measuring depression. Participants complete both the new questionnaire and the Beck Depression Inventory (BDI). If participants obtain similar scores on both measures, the new questionnaire has good concurrent validity.

How is it assessed?
Compare participants' scores on the new measure with scores on an established, validated measure.

How can it be improved?

• Compare the new measure with a recognised validated test.

• Ensure both tests measure the same psychological construct.

Ecological validity

Definition
Ecological validity is a form of external validity that focuses on the extent to which research findings can be generalised to other settings or everyday life.

Example
Milgram's obedience study has been criticised for having low ecological validity because administering what participants believed were electric shocks in a laboratory does not reflect behaviour in everyday life.

How can it be improved?

• Use tasks that are more representative of everyday behaviour.

• Conduct research in natural settings where appropriate.

(I would avoid saying simply "carry out the study in a natural setting." The current AQA guidance emphasises that ecological validity is mainly about how realistic the task is, not just where it takes place.)

Temporal validity

Definition
Temporal validity is a form of external validity that focuses on the ability to generalise findings beyond the particular historical context of the study.

Examples

• Asch's (1951) conformity study may have lower temporal validity because social attitudes and levels of conformity may have changed since the 1950s.

• Research investigating attitudes towards mental illness conducted several decades ago may also have lower temporal validity because public understanding and acceptance of mental illness have changed over time.

How can it be improved?

• Replicate studies with contemporary participants.

• Repeat research at different points in time to determine whether the findings remain applicable.

Does Your First Attachment Shape Your Adult Relationships?

When we think about our relationships as adults, we often focus on our current experiences. But psychologists have long asked a fascinating question:

Can the bond we form with our first caregiver influence the relationships we have later in life?

According to attachment theory, the answer may be yes—but it's more complex than many people realise.

What is attachment?

Attachment is the emotional bond that develops between an infant and their primary caregiver. According to psychologist John Bowlby, this early relationship provides children with security, comfort and protection during the most important stages of development.

Bowlby believed that these first experiences create an Internal Working Model—a mental blueprint that helps us understand ourselves, other people and relationships.

If a child experiences a secure attachment, they may grow up believing that others are trustworthy and that they themselves are worthy of love. In contrast, inconsistent or insecure attachments may make later relationships more challenging.

The research

One of the best-known studies into adult relationships was carried out by psychologists Hazan and Shaver.

They placed a questionnaire, known as the "Love Quiz," in an American newspaper and asked adults about both their childhood attachment experiences and their romantic relationships.

The researchers found that adults who reported secure childhood attachments were more likely to have happy, trusting and long-lasting romantic relationships. Those who reported insecure attachments were more likely to experience jealousy, fear of intimacy or difficulties maintaining relationships.

These findings appeared to support Bowlby's idea that early attachment can influence later relationships.

Is childhood destiny?

Not necessarily.

Although early experiences are important, psychologists now recognise that people continue to develop throughout their lives.

Positive friendships, supportive partners, therapy, education and other life experiences can all influence the way we see ourselves and other people. Research has shown that attachment patterns are not fixed and can change over time.

This is encouraging because it reminds us that our past does not have to determine our future.

What does this mean for psychology students?

If you're studying AQA A Level Psychology, this debate is central to the Attachment topic.

When evaluating Bowlby's theory, it's important to consider both sides:

• Research supports the idea that early attachment can influence adult relationships.

• However, later experiences also play an important role, suggesting that attachment is not entirely fixed or deterministic.

Strong exam answers explain both perspectives before reaching a balanced conclusion.

Final thoughts

Our earliest relationships may leave a lasting impression, but they do not define who we become.

Psychology shows us that people are capable of growth, resilience and change throughout life. Understanding attachment theory helps us appreciate both the importance of childhood and the remarkable ability of human beings to adapt.

Looking for AQA Psychology tuition?

I have over 25 years' experience teaching Psychology, including as a Head of Department and AQA Examiner. My online lessons are tailored to each student's needs, focusing on subject knowledge, exam technique and building confidence.

If you're preparing for GCSE or A Level Psychology, I'd be delighted to help you achieve your goals.