Psychiatric assessment

A full psychiatric assessment includes a comprehensive biopsychosocial history and mental state examination as for the general population. Accurate psychiatric diagnosis can be difficult in people with developmental disability—referral to, or liaison with, a specialist should be sought where there is uncertainty or complexity. See also Psychiatric screening tools and diagnostic criteria.

Medical assessment is important to exclude physical contributors to symptoms (eg pain) and assess for comorbidities. Consider adverse effects of medications (including complementary and alternative therapies) that may cause or exacerbate a psychiatric condition.

In a person with developmental disability, deterioration or change in baseline function or behaviour can indicate a psychiatric disorder. Ascertain the premorbid levels of:

  • behaviour, personality style
  • functioning including capacity for self-care, communication, daily living skills, social skills, education and usual activities.
Note: Deterioration or change in function or behaviour can indicate a psychiatric disorder in a person with developmental disability.
Perform physical examination and investigations as indicated. See Investigations to consider in psychiatric assessment of a person with developmental disability for investigations to consider in psychiatric assessment of a person with developmental disability. For advice on facilitating examinations, see Physical examination and investigations and Communicating with people with developmental disability.
Figure 1. Investigations to consider in psychiatric assessment of a person with developmental disability.

[NB1]

Basic screening tests in the psychiatric assessment of a person with developmental disability may include:

  • blood tests—full blood count, urea and electrolyte concentrations, liver biochemistry, thyroid function tests, vitamin B12, folate, iron studies, triglyceride profile, glucose
  • urine microscopy, culture and sensitivity
  • urine drug screen (eg illicit drugs)
  • electrocardiogram (ECG).

Consider genetic testing if the cause of developmental disability is not known (eg chromosome microarray, fragile X).

Depending on presenting signs and symptoms, consider:

  • head scan—computerised tomography (CT) or magnetic resonance imaging (MRI)
  • electroencephalogram (EEG)
  • plain abdominal X-ray—to exclude constipation
  • referral for assessment of adaptive behaviour.
Note: NB1: In children and young people with developmental disability, consider referral or seeking specialist advice (eg developmental paediatrician, paediatric psychiatrist) before performing investigations.

Consider using a disability health assessment template to prompt information gathering; see Comprehensive health assessments. These are specific to people with developmental disability, and help to identify health problems that are often missed in this group. For a list of health problems that are common in people with developmental disability and may manifest atypically (eg with behaviour change), see:

Key questions for a psychiatric history include presence of features outlined in Key questions for a psychiatric history in people with developmental disability, as for the general population.
Figure 2. Key questions for a psychiatric history in people with developmental disability.

[NB1]

Although people with developmental disability have the same symptoms of psychiatric disorders as the general population, psychiatric disorders are often missed or misdiagnosed. It is important to ask about:

  • pervasive mood disturbance
  • neurovegetative symptoms
  • thought content (eg worries, paranoia, obsessions)
  • disorganised thinking or speech
  • hallucinations
  • rituals or compulsions
  • suicidal or aggressive thoughts
  • unusual posturing, movements, grimacing, eye gaze, facial expressions, slowing, agitation.
Note: NB1: In children and young people with developmental disability, consider referral or seeking specialist advice (eg developmental paediatrician, paediatric psychiatrist) on assessment and management.

Psychiatric disorders may present with challenging or changed behaviour. New or worsening challenging behaviour needs careful evaluation for environmental, physical and pharmacological triggers (see Initial assessment and clinical support for challenging behaviour in a person with developmental disability). Changes can include repetitive behaviour, picking, biting, pacing, motor retardation, aggression and self-injurious behaviour.

In addition to assessment of the presenting complaint, obtain a history for the following key areas:

  • developmental disability, including the cause of disability if known; childhood cognitive or developmental assessments
  • presence of underlying intellectual disability and autism spectrum disorder
  • past medical and psychiatric assessments
  • family history of intellectual disability, autism spectrum disorder or psychiatric disorder
  • childhood history (including attachments, losses, abuse, home environment)
  • environmental factors—level and stability of support, activities available, recent changes, losses and separations
  • past and current medications and psychological interventions.

For the assessment of specific psychiatric disorders in people with developmental disability, see: