Special Interest: Mental health

Co-occurring severe mental illness, usually schizophrenia or bipolar affective disorder, and substance misuse is termed dual diagnosis. Mental illness and its consequences may lead to substance misuse as a coping strategy. Substance misuse can lead to mental health problems, either by triggering a first episode in a susceptible person, or by exacerbating an existing disorder. However, substance misuse itself is unlikely to be the sole cause of a severe and enduring mental illness.

It is estimated that up to 80% of patients with Parkinson’s disease will eventually develop cognitive impairment over the course of their illness. Even at the time of diagnosis, cognitive impairment has been reported in 20-25% of patients. Commonly affected domains are executive function, visuospatial ability and attention control. In addition, patients with Parkinson’s disease dementia may present with deficits in language function and verbal memory.

The diagnosis of post-traumatic stress disorder (PTSD) differs from most psychiatric disorders as it includes an aetiological factor, the traumatic event, as a core criterion. The DSM 5 core symptoms of PTSD are grouped into four key symptom clusters: re-experiencing, avoidance, negative cognitions and mood, and arousal. Symptoms must be present for at least one month and cause functional impairment.

Major (unipolar) depression is one of the most common mental health disorders in children and adolescents, with an estimated one year prevalence of 4-5% in mid-late adolescence. Depression is probably the single most important risk factor for teenage suicide, the second to third leading cause of death in this age group and a forerunner of adult depressive disorder. Half of those with lifelong recurrent depression started to develop their symptoms before the age of 15 years.

Type 2 or complex trauma results from multiple or repeated traumatic events occurring over extended periods. Complex trauma is often associated with other adversity and stressors such as neglect, loss or deprivation. For many individuals these traumas occur at a developmentally vulnerable time with the perpetrator often in a caregiving role. Patients who have experienced complex trauma should be assessed for the core symptoms of PTSD. In addition, patients should be assessed for disturbances in the three domains of emotional dysregulation, negative self-concept and interpersonal disturbances.

The symptoms of depression in adolescents are similar to those in adults. Depression in children of primary school age may be very subtle and symptoms include mood fluctuations, tearfulness, frustration or temper tantrums. If depression is suspected, it is essential to evaluate the degree of risk. Risk has two key aspects: the likelihood of a potentially harmful incident occurring and degree of potential harm.

Anxiety disorders are among the most common mental health disorders of childhood. Three quarters of anxiety disorders have their origins in childhood, with presentation often chronic in nature. Where the child is experiencing significant distress or functional impairment (e.g. missing school, not taking part in age-appropriate activity), then specialist input is likely to be needed.

The postnatal period appears to be associated with higher rates of adjustment disorder, generalised anxiety disorder, and depression. Women who have a history of serious mental illness are at higher risk of developing a postpartum relapse, even if they have been well during pregnancy. Postnatal depression is more severe than baby blues, follows a chronic course and may relapse outside the perinatal period. Bipolar disorder may present as a first depressive episode in pregnancy or the postnatal period. In the postpartum period women have a high risk of severe relapse.

Depression in older adults is common. Depressive symptoms may be part of a recurrent depressive disorder or experienced for the first time in later life as a result of changes in risk and resilience factors. There is an association between cerebrovascular pathology, vascular risk factors and depression. Physical illnesses, particularly those associated with frailty, are also important risk factors for depression. Depression has a distinct presentation in late life and low mood may not be the predominant presenting symptom. Older patients may present with physical symptoms, apathy, cognitive symptoms, agitation, retardation, fatigue or weight loss.

Anxiety disorder in the elderly is twice as common as dementia and four to six times more common than major depression. Anxiety is associated with poorer quality of life, significant distress and contributes to the onset of disability. Mortality risks are also increased, through physical causes, especially cardiovascular disease, and suicide. Diagnosing anxiety disorders in older adults remains a challenge because of the significant overlap in symptoms between physical disorders and depression.

A large Swedish study has suggested that gabapentinoid medications are associated with an increased risk of suicidal behaviour and unintentional overdose in adolescents and young adults.

Intensive blood pressure (BP) control reduces the risk of developing mild cognitive impairment, but not dementia, a US randomised trial has found.

Apathy symptoms may identify older patients who are at increased risk of developing dementia, a Dutch prospective cohort study has found.

Cancer patients are at increased risk of suicide, particularly in the first six months after diagnosis, a national population-based study in England has found. Compared with the general population, cancer patients had a 20% increased risk of suicide; standardised mortality rate (SMR) 1.20. The risk of suicide was highest during the first six months after diagnosis, SMR 2.74 (95% CI: 2.52-2.98), but remained raised for three years.

Antidepressant, urological and anti-parkinsonian drugs with definite anticholinergic effects are associated with an increased risk of incident dementia up to 20 years after exposure, a UK nested case-control study has found. The study authors conclude: 'Clinicians should continue to be vigilant with respect to the use of anticholinergic drugs, and should consider the risk of long-term cognitive effects, as well as short-term effects, associated with specific drug classes when performing their risk-benefit analysis.'

Maternal pre-eclampsia is associated with an increased risk of autism spectrum disorder (ASD) in offspring, a meta-analysis has found. Compared with unexposed offspring, children who were exposed to pre-eclampsia in utero were 32% more likely to develop ASD.

A high sugar intake is associated with an increased incidence of common mental disorders in men, but not in women, a UK prospective cohort study has found. The Whitehall II study recruited a cohort of 10,308 civil servants (6,895 men and 3,413 women) in 1985-88. During the 25-year follow-up period, diet was assessed on four occasions using a food frequency questionnaire. Compared with those in the lowest tertile, men in the highest tertile of sugar intake had significantly increased odds of incident common mental disorder five years later.

Job strain, a combination of high demand and low control, is associated with an increased risk of subsequent clinical depression, a meta-analysis has found. Patients who report stress at work are both more likely to be depressed and more likely to become depressed. In the UK in 2015/16, work-related stress accounted for 37% of work-related ill health and 45% of working days lost. When helping patients get back to work it is important to discuss ways of reducing job strain and the demand control support model provides a helpful framework.