CHAPTER 4 Organic psychiatry
General medical conditions are associated with psychological disorders in several ways. This chapter is not meant to be comprehensive, but rather aims to bring attention to important links between psychological function and other body functions. The presence of psychological illness does not exclude the presence of general medical illness and vice versa, even if the diagnosis explains all of the symptoms.
The presence of relevant general medical disorders (‘organic disorders’) must be considered with any presentation of psychological illness, particularly when severe or resistant to treatment. The interaction between general medical disorders and psychological disorders is complex and requires careful consideration. This chapter considers a variety of general medical or organic disorders that can cause significant psychological illness. Box 4.1 presents some of the more common associations between psychological symptoms and general medical disorders.
BOX 4.1 Common psychological disorders and potential contributing general medical disorders
Depressive disorders
Psychiatric disorders secondary to medical disorders
Delirium
Delirium is a syndrome characterised by concurrent disturbances of consciousness and attention, perception, thinking, memory, psychomotor behaviour, emotion and the sleep–wake cycle. Typical symptoms are shown in Box 4.2.
BOX 4.2 Typical symptoms of delirium
Management ultimately requires identification and appropriate treatment of the underlying cause. Management of immediate symptoms and reducing distress for the individual encompasses adequate lighting (to minimise misinterpretation of visual information), minimal noise, a calm, positive and reassuring approach, and a secure environment to maintain safety of self and others. Antipsychotic medications (see Box 4.3) can be helpful for the heightened arousal, anxiety and florid psychotic symptoms, but the response to treatment is often disappointing until the basic cause has been relieved.
BOX 4.3 Medications for the management of delirium
Dementia
Dementia is a syndrome secondary to brain disease which is progressive in nature and is accompanied by disorder of multiple higher cortical functions, including memory, thinking, orientation, comprehension, calculation, learning capacity, language and judgment. It is usually accompanied by deterioration in emotional regulation, social behaviour and/or motivation. It may occur at any age, but is most common in later life. Some forms are reversible, but many are not: common reversible and irreversible types of dementia are shown in Box 4.4. For more on dementia, see Chapter 17.
Huntington’s disease
Clinical features
Onset of the clinical syndrome can occur in adolescence, but is most commonly observed in the fifth decade. Cognitive dysfunction occurs early in the progression of the disease and may include impairment of memory (declarative and non-declarative), impairment of executive cognitive functions (e.g. verbal fluency, planning and sequential activities) and visuospatial skills. Abnormal movements are characteristic of the disease and include chorea and choreoathetosis, as well as impaired occulomotor functions, coordination of movement, dysphagia and dysarthria. Rigidity, bradykinesia, myoclonus/epilepsy, bruxism and dystonia may also arise. Apathy, irritability/aggression, dysphoria, generalised anxiety and obsessive-compulsive disorder arise commonly. Major mood disorders (major depressive disorder or bipolar disorder) and schizophreniform psychosis are seen in many patients with Huntington’s disease. The risk of suicide is very high once the diagnosis has been made.
Management
tetrabenazine (25 mg twice daily, increasing to a maximum of 200 mg daily); side effects can include sedation, depression, insomnia, dysphagia and Parkinsonism, or
Psychosis is treated using antipsychotic medications (see Ch 13). Myoclonus and epilepsy can be usefully helped with anticonvulsants, and botulinum toxin has been employed for bruxism and dystonia. Depression and anxiety disorders require antidepressants.
Acquired brain injury
Post-concussional syndrome and mild traumatic brain injury (TBI)
Mild TBI is defined as closed head injury which is associated with brief loss of consciousness (less than 20 minutes) or none, and anterograde amnesia of less than 24 hours. This may be accompanied by a ‘post-concussional syndrome’ (see Box 4.5).
