Epidemiology and Mental Health

Epidemiology and Mental Health

• Mental health diagnosis differs from physical health diagnosis
• Mental health diagnoses are circular, describing symptoms rather than explaining underlying causes
• Current classification systems (DSM and ICD) provide symptom profiles but lack information about root causes

Prevalence and Impact

• Mental health problems are extremely common; impacts one in two people during their lifetime.
• In the UK, one-third of the disease burden in people in their 20s and 30s results from mental illness
• The economic cost of mental illness in the UK is substantial, totaling an estimated 99 billion pounds annually

Research and Symptom Understanding

• Specific mental health disorders lack unique risk factors or biomarkers
• Symptoms of conditions like depression and anxiety often form a single, interconnected cluster
• Common risk factors include stress and experiences of abuse

Key Challenges in Mental Health

• Current diagnostic systems are relatively new and constantly evolving.
• Research is often siloed and focused on specific disorders
• Mental health receives minimal research investment compared to other health issues
• Social stigma remains a significant barrier to mental health understanding and treatment
• People are less comfortable discussing mental health compared to physical illnesses

Recommended Approaches

• A broader prevention strategy is recommended
• Address common risk factors across mental health conditions.
• Increase research funding and investment.
• Challenge existing stigmas and diagnostic frameworks

Preparatory Lecture Outline

• Outline included Prevalence, Developmental Patterns, and Inequalities
• Time Trends, Perspectives, Risk and Protective Factors are also included in outline

Disease Burden on Mental Health

• Disease Burden = Impact of a health problem, as measured by factors such as financial cost, mortality, morbidity, or other indicators related to life quality.
• Burden is usually measured by two indicators: number of years of life lost to disease AND number of years lived with disability, as a result of the disease
• Higher disease burden indicates a larger impact compared to other health factors for that age group
• Graph shows that mental health disease is high in proportion for younger people
• Almost a third of disease burden in people in their 20s is mental health related
• Older individuals are more likely to experience multiple health issues, which dilutes the burden of mental health
• Younger people are generally healthier, which might inflate the perceived burden of mental health.

Mental Health Through the Life-Course

• 80% of mental health disorders onset in adolescence
• Consequences of mental health disorders are felt through adulthood and mid-life
• Consequences felt throughout adulthood, leading to potential comorbidities

Prevalence of Mental Health Disorders

• Disorders/symptoms are usually grouped into broader categories: Emotional / behavioural / hyperactivity / other
• Externalising = largely but not exclusively ‘behavioural' or ‘hyperactivity'
• Internalising = largely but not exclusively ‘emotional'
• 5% of people experience more than one disorder
• 12.8% experience a single disorder
• 82.2% experience no disorder
• Emotional disorders are most common, followed by behavioural disorders
• There is a significant number of ASD, tics, and eating disorders

Emotional vs Behavioural Disorders

• Young people are more likely to have an emotional disorder than a behavioural disorder
• Tend to occur in later childhood
• Emotional disorders often occur in later childhood, but are difficult for parents or carers to recognise because children haven't developed the vocabulary or comprehension to express their emotions.
• Clinicians and carers also find it difficult to distinguish between developmentally normal emotions, such as fears and crying, from severe and prolonged emotional stresses, i.e disorders.
• Behavioural disorders can be diagnosed earlier than emotional disorders, which helps disorders to be treated early and effectively – also contributing to the drop off in adulthood.
• Low intensity, defiant and impulsive behaviour once in a while in very young children, can be regarded as normal (losing your temper or minor destruction of property)
• Extremely difficult and challenging behaviours outside the norm for age and development at the time, should be recognised as behavioural disorders

Sex Differences in Prevalence

• Survey-based, measuring sub-clinical symptoms - e.g PHQ
• Measuring sub-clinical symptoms - e.g. PHQ
• MCS = Birth Cohort Study (children born between 2000 & 2001) follows the lives of children from birth until death or dropout.
• 2:20 or 10% of boys scored above threshold for depression
• 4:20 or 25% of girls scored above threshold for depression
• Depressed girls more commonly report feelings of sadness, guilt, punishment, worthlessness, low energy and fatigue
• Depressed boys commonly have symptoms of irritability, suicidal thoughts or desire to reduce pressure
• Higher prevalence of emotional disorders in females than males
• Also more dramatic increase due to presenting later in childhood
• Higher prevalence of behavioural disorders in males than females
• Differences often attributed to gender differences include acquisition of expectations associated with traditional gender roles, help seeking, coping, and socioeconomic status.
• Potential measurement bias is a factor, due to questions over the effectiveness of surveys measuring specifically mental health experiences of men

Socio-Economic Context

• In adulthood, those in managerials jobs residing in rural areas are more likely to have better mental health
• White British young people have the highest prevalence of mental health disorders at young ages, while Asian have the lowest
• People who identify as LGBT have much higher prevalence of mental health difficulties, especially in childhood and adolescence

Time-Trends: Adolescent Mental Health and Other Health Outcomes

• Mental health difficulty changes over 10 years
• For all measures, the mental health prevalence was higher for young people in 2015 than 2005 over generations in most cases
• Substance use/abuse substance changes over 10 years
• Important due to bi-directional relationship between substance, making casual inferences difficult
• Antisocial behavior changes over 10 years
• Indicates antisocial behaviors aren't mediating factors in mental health change over generation
• Health factors, commonly related with emotional or internalising disorders, have increased over generations
• Relationship to increasing health indicators

Access to Services

• 25% of young people with mental health difficulties seek treatment
• 25% of young people are referred for treatment
• There are delays of months before most young people are able to actually get treatment after referral
• Less than 10% of UK mental health budget spent on young people

Proxy Reporters

• Proxy reporters for child health are frequently parents and teachers
• Children may be too young to verbalise their mental health concerns
• There is positive self-evaluation
• Self-report can miss certain disorders
• Important to gather information on healthcare utilisation - useful for research
• Use of proxies is more important in life
• Study found concordance = fairly low; community vs. clinical setting: community r = 0.2 - 0.3 vs. clinical r = 0.5 - 0.6
• There is increased likelihood that perceived social-economic status is important over actual
• Age differs with other factors, such as socio-economic status
• For emotional, behavioural, and hyperactivity disorders, children often rate their health more negatively than parents will
• Teachers are somewhere in the middle: Teachers are known to rate the mental health of children from lower income backgrounds as lower, irrespective of the child rating

Risk and Protective Factors for Mental Health in Young People

• Largest risk factors: Problems getting along with peers; Arguing with parents
• Individual risk factors: Communication difficulties; Chronic illness

Protective Factors

• Protective factors: High family income; Engaging with school
• Blue = individual characteristic; Red = family relationships & home life; Green = economic circumstances; Purple = school

Range of Antecedents

• The below predict the severity of mental health disorders
• Family and Environment = Lone parent; Siblings; Maternal distress; Paternal distress; Parent relationship; Parent-child conflict; Parent-child closeness

Differentiation Between Disorder

• Unique environemental and biological risk factos for mental health difficult to identitfy
• The below are more likely to be linked to behavioural disorders: Sex, ethnicity, and maternal age at birth
• Smoking during pregnancy
• Parental conflict
• Apprehension-withdrawal

Thinking about Prevention

• Most mental health intervention is reactive: focuses on treatment after disorder onset
• Early intervention reduces costs
• Lower costs and betters prognosis or individuals
• Can protective factors mitigate the effects of risk factors of symptom development?

Population Cohort Comparison

• Revealing a concerning increase in depressive symptoms, self-harm, and obesity in 2015
• Reveals a concern of increase in substance, antisocial behavior, and sexual activity that either either decreased or remained stable
• Utilising methods such as propensity score matching and entropy balancing, the study adjusted for demographic differences and examined sex differences in behaviors.

Key Insights

• There is a significant increase in depressive symptoms and self-harm among UK adolescents from 2005 to 2015.
• Obesity rates have also risen, indicating a concerning trend in physical health alongside mental health challenges.
• Substance use and antisocial behaviors have either decreased or remained stable, suggesting a shift in some health-related behaviors.
• The study reveals sex differences in certain behaviours, with females showing lower odds in specific areas.
• Adjust for demographic differences between the to cohorts.
• The research found that substance use and antisocial behaviours either decreased or remained unchanged from 2005 to 2015, contrasting with the rise in mental health issues.