e special issues associated with IDD. Fortunately the Diagnostic Manual-Intellectual Disability and Diagnostic Criteria-Learning Disability are now available to assist clinicians in negotiating a clinical diagnosis.
The diagnosis and treatment of mental disorders in adults with IDD requires that the clinician is able to negotiate two worlds. As a team member, the psychiatrist often plays the role of translator between the world of the neurosciences and biomedicine and the team. As we have seen, the differential diagnosis can present some of our greatest challenges. For example, schizophrenia is frequently diagnosed and treated based on the presence of hallucinations or delusions without a comprehensive exploration of psychosis; psychotic forms of major depressive, bipolar disorder, PTSD, delirium, dissociative states and intoxication can occur (3). A parallel problem arises when clinicians prescribe psychopharmacological treatment for aggression, self-injury, agitation and disruptive/destructive behaviors without thorough reviews of environmental factors (social ecology), review of neurobiological setting events and functional behavioral analyses. In either of these scenarios the rush to treat can result in the long-term exposure but often ineffective treatment regimens that all too often result in unnecessary polypharmacy (30, 44).
Traditionally, most mental health clinicians accept the view that mental disorders arise from the interaction between psychosocial stresses and biological/genetic risks for a particular mental disorder (“two hit theories”). Some colleagues take a different approach, viewing challenging behaviors as learned phenomena. These behavioral specialists tend to focus less on accurate diagnosis and biogenetic etiology (8). Yet in light of our current knowledge, neither approach provides the ultimate solution. As clinicians we need to consider both challenging behaviors and mental disorders as lying on a continuum. From this perspective, challenging behaviors are attributed to environmental stressors and patterns of reinforcement or consequences; mental disorders, consequences of complex gene-environmental interactions. On closer analysis, gene-environmental interactions also bias the individual toward specific behavioral reactions to specific circumstances and the risk for psychiatric disorders. Sorting out these complex relationships and matching them with current evidence-based treatment or best practices are some of our greatest challenges.
Mental health professionals entering the world of IDD and dual diagnosis must be open to learning from other disciplines while thinking through problems both systemically and systematically. The time-consuming, multidisciplinary nature of assessment, diagnosis and treatment planning requires understanding of many bodies of knowledge. For psychiatrists, the challenge is to view psychopharmacological interventions as but one component of a complex toolkit (Table 1).
Table 1.Psychopharmacology Pearls for Patients with IDD
| Add to My POL
|1. Most consultation patients present with multiple psychiatric diagnoses. Occam’s Razor should be applied prior to prescribing. Syndrome diagnoses are not based on single symptoms.|
|2. Challenging behaviors are heterogeneous states, before prescribing carefully review the functional behavioral analysis, previous diagnoses, previous behavioral and medication treatments and your differential diagnosis. The idea of single drug/ neurotransmitter per challenging behavior can get you into trouble.|
|3. Keep up with what is on the Internet. Families do and some are trying things and may not tell you. The National Institutes of Health has a website on Complementary and Alternative Medicine that can help you keep current. Have caregivers bring all medications, especially OTC or alternative meds.|
|4. Evidenced based treatments for neurotypical patients are essential BUT these studies may not have included patients with IDD or Autism Spectrum Disorders. Pharmacokinetic and pharmacodynamic differences can have a significant impact. The old