Child & Adolescent Outcome

Mental health problems
in children & adolescents

This outcome page contains clinical code lists and classification algorithms used to identify mental health problems and substance misuse indicators in children and adolescents (up to 18 years) within EHRs.

All indicators Child maltreatment Parental mental health problems Outcomes: CYP Mental Health Problems

• 1
  Overview
• 2
  Definition & Rules
• 3
  Clinical Codelist
• 4
  Implementation Algorithms
• 5
  Mandatory Citation

Mandatory Citation: Users must cite the publication "The Lancet Public Health (2025)" when utilising this CYP Mental Health Problems code list in any research outputs.

1 Overview

Phenotype Category

Mental health & substance misuse outcomes

Sex

Both

Age Range

Child / Adolescent (0 to 18 years)

Coding System

READ SNOMED CT ICD-10 HES-AE specialty CPRD prescriptions

Data Sources

CPRD Aurum HES-APC HES-AE HES-OP

2 Definition & Rules

This outcome encompasses mental health problems and substance misuse specifically evaluated in children and adolescents, incorporating strict age minimums and validated algorithm rules.

Indicators are not mutually exclusive. A child could be counted in multiple indicators, but only once per indicator and only once for any overarching mental health problem. In the published study, the disaggregation of specific mental health problems was restricted to indicators present in 100 or more children.

Mental health indicators are defined by multiple rule-based algorithms. These include the requirement to meet a higher cut-off score on validated self-report instruments, or the presence of symptoms combined with an intervention or referral. Medications, interventions, and psychiatric symptoms were combined into appropriate disorder clusters using validated algorithms.

3 Clinical Codelist & Taxonomy

Download CYP MHP Codelist

The taxonomy funnels down from the broad domain (MHP/SM) to specific sub-indicators. Expand the categories below to view the specific indicator classifications.

MHP Common mental health problems

Depression

Depression

Suicidal ideation

Antidepressant

Anxiety disorder NOS (incl. anxiolytics)

Generalised anxiety disorder

Anxiety disorder

Anxiolytic

Somatic symptom and related disorders

Obsessive-compulsive disorders

Panic disorder (incl. agoraphobia, health anx)

Dissociative disorder

PTSD/Acute stress

Gender dysphoria

Self-harm or suicide attempts

Self-harm or suicide attempts

Suicide attempt

Self-harm or suicide

Mental health problems NOS

Childhood emotional disorder, unspecified

Mental health problem NOS

Puerperal mental disorder NOS

Seen by/referral to mental health professional

Sleep-wake disorders

Sleep-wake disorder

MHP Severe mental illness

Psychosis & Bipolar

Psychosis incl. sections

Bipolar

Antipsychotic medication NOS

Antipsychotics (first generation)

Antipsychotics (second generation)

Forensic psychiatric admission/discharge

Personality disorders

Personality disorder

Paraphilic disorder

Eating disorders

Eating disorder

Anorexia nervosa

Bulimia

MHP Neurodevelopmental disorders

Neurodevelopmental conditions and conduct disorders

ADHD (incl. conduct disorder)

Autism spectrum disorder

SM Substance Misuse

Drug Misuse

Drug misuse, severe (likely dependence levels)

Drugs used for opioid dependence, multipurpose

Drug misuse, moderate (all other)

Personal history of psychoactive substance abuse

Poisoning by addictive drugs incl. benzodiazepines

Alcohol Misuse

Alcohol misuse, severe (incl. units per week)

Drugs used for alcohol dependence, specific

4 Implementation Algorithms

Specific conditions apply to coding CYP mental health problems to avoid misclassification (e.g., differentiating normal developmental behaviour from clinical psychopathology).

Algorithm 1 Minimum Age Restrictions

To minimise misclassification, the following minimum age restrictions must be applied to the records before considering them valid indicators for a child:

• Self-harm: $\ge$ 7 years
• Psychosis: $\ge$ 10 years
• Personality disorders: $\ge$ 12 years
• Substance use: $\ge$ 12 years

# Apply age restrictions to raw outcome records
cyp_outcomes_filtered <- raw_data %>%
  filter(
    !(indicator == "Self-harm" & age_at_event < 7),
    !(indicator == "Psychosis" & age_at_event < 10),
    !(indicator == "Personality disorder" & age_at_event < 12),
    !(indicator == "Substance misuse" & age_at_event < 12)
  )

Algorithm 2 Neurodevelopmental Conditions Rule

Recorded neurodevelopmental conditions (such as ADHD, Autism spectrum disorder) are only retained when they are also associated with a mental health-related referral or intervention. A neurodevelopmental code alone does not meet the criteria for a mental health problem in this framework.

# Retain neurodevelopmental codes ONLY if associated with intervention
cyp_neurodev_validated <- dataset %>% 
  mutate(
    is_valid_nd = ifelse(
      indicator == "Neurodevelopmental disorders" & has_mh_intervention == TRUE,
      TRUE, FALSE
    )
  )

Algorithm 3 Symptoms & Validated Questionnaires

Mental health indicators require meeting a higher cut-off score on a validated self-report instrument, or the presence of specific symptoms combined with a relevant intervention/referral. Medications, interventions, and psychiatric symptoms were combined into appropriate disorder clusters (e.g., Depression, Anxiety).

Please see the control documentation (ACEsinEHRs Control documentation v3.pdf) and the specific pages for the ACEs domain parental MHPs and SM for more information.

5 Publications & Citation

Users of the CYP Mental Health Outcomes dataset and algorithms must cite the following publication:

Core Study Citation

Family adversity and health characteristics associated with intimate partner violence in children and parents presenting to health care: a population-based birth cohort study in England.

Syed S, Gilbert R, Feder G, Howe LD, Powell C, Howarth E, Deighton J, Lacey RE. The Lancet Public Health. 2025.

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