Meta-analysis topic ideas in psychiatry and mental health

Mental health research has some of the most heavily reviewed topics in medicine, such as antidepressants and cognitive behavioural therapy. It also has fast-growing areas, like digital interventions and treatment for young people, where studies pile up before anyone has pooled them.

Because outcomes are mostly rating scales and control conditions vary, a good review in this field is as much about careful definitions as about the pooled number.

Find a psychiatry and mental health topic that has not been done

SynthGap searches the published literature, checks each candidate against existing systematic reviews, and proposes topics with the primary studies behind them. The free plan includes 3 discovery runs a month.

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Where gaps tend to hide in mental health

Digital and remote interventions

App-based and online therapies change quickly, and reviews are often limited to one condition or one type of delivery.

Children, adolescents and older adults

Adult evidence is often applied to other age groups without direct trials. Pooling the trials that exist for a specific age group can be a clear gap.

Long-term outcomes

Most trials stop at the end of treatment. Reviews of relapse and function at 6 to 12 months or longer are less common.

Harms and discontinuation

Adverse effects and withdrawal are reported inconsistently, and pooling them separately from benefit is a distinct question.

Comorbidity

Depression with a physical illness, or anxiety with substance use, is studied in many small trials that are rarely brought together.

Outcomes and effect measures that pool well in mental health

Symptom scores (for example HAM-D, MADRS, PHQ-9, GAD-7): standardised mean difference when scales differ, mean difference when they are the same.
Response and remission: risk ratios, with the definition (for example a 50 percent score reduction) stated, since it varies between trials.
Dropout for any reason, used as a measure of acceptability: risk ratio.
Relapse over a stated follow-up: risk ratio or hazard ratio.
Suicidal behaviour is rare, so pooled estimates need many participants and often use odds ratios or sparse-data methods.

Common traps in mental health reviews

Placebo and expectation effects are large. Antidepressant trials have also been shown to have selective publication (Turner and colleagues, 2008), so check for missing results.
Psychotherapy trials cannot blind participants, and wait-list controls tend to make the treatment look better than an active comparison would.
Researcher allegiance: the people who developed a treatment tend to report better results for it.
Mixing different rating scales, time points and populations (for example mild and severe depression) in one estimate.

Check before you commit

Before committing months to a topic, check that nobody has beaten you to it. Search PubMed with its systematic review filter, the Cochrane Library, the PROSPERO register (for reviews that are registered but not yet published) and Epistemonikos. Look at how recent the latest review is and whether new trials have appeared since its search date. Step-by-step guide.

Starting points to try in SynthGap

These are areas to explore, not claims that they are open. Some may already be well covered, and finding that out quickly is the point.

Guided digital cognitive behavioural therapy for adolescents with anxiety
Long-term relapse prevention after psychotherapy for depression
Exercise as an add-on treatment for depression in people with a chronic physical illness

Questions

Which mental health topics are probably already saturated?

Broad questions such as antidepressants versus placebo, or cognitive behavioural therapy for depression in adults, have many reviews. Narrow by population, delivery format, comorbidity or outcome to find room.

Should I use standardised mean difference or mean difference?

Use mean difference when every trial uses the same scale, and standardised mean difference when scales differ. Always translate the result back into a clinically meaningful unit where you can.

How should I handle wait-list controls?

Analyse wait-list, treatment-as-usual and active comparators separately. Pooling them together overstates the benefit.

Other specialties

This page is general methodological guidance, not medical advice, and it does not list specific unreviewed topics. SynthGap's suggestions are AI-generated from the published literature, so verify them before registering a protocol.