Selecting Antipsychotic Therapies for Psychotic Disorders

Antipsychotics should be started as soon as the signs of psychosis are observed in a patient, so that a full-blown psychotic episode may be avoided.

Psychotic disorders are a group of illnesses that affect an individual’s mind, altering his or her ability to think clearly, make rational judgments or decisions, communicate effectively, understand reality from imagination, and behave appropriately in public.1

About 1% of the world's population has a psychotic disorder.2 The symptoms significantly impair the ability to engage in normal functioning, so affected individuals cannot meet the demands or obligations of everyday life. However, even the most severe psychotic disorders can be treated.

The 3 major types of major psychotic disorders are mood disorders, psychosis associated with neurological conditions, and schizophrenia and schizophrenia-like disorders, which are the most debilitating and costly of all.

Schizophrenia is characterized by a mixture of symptoms impacting perception, cognition, emotions, behavior, attention, concentration, motivation, and judgment.3 The negative or deficit symptoms of schizophrenia can include social withdrawal and psychomotor retardation,4 whereas the positive symptoms can include delusions, hallucinations, agitation, or disorganized speech. While the pathophysiology of schizophrenia's negative symptoms remains unknown, the positive symptoms are thought to be related to a hyperactive dopamine system.5

For the most part, the symptoms of psychotic disorders can differ from 1 individual to another, but the most commonly observed ones are delusions and hallucinations. The exact causes of psychotic disorders remain unknown, but they are believed to be related to a variety of genetic, medical, and environmental factors.5 While these origins are still elusive, researchers and scientists have been able to develop pharmacotherapies that have been instrumental in targeting the core symptoms of specific psychotic disorders, whether they are predominately negative, positive, cognitive, or mood symptoms.

Antipsychotics should be started as soon as the signs of psychosis are observed in a patient, so that a full-blown psychotic episode may be avoided through early intervention.5 Biomedically, antipsychotics are thought to reduce dopamine transmission centrally, which is related to the blockage of postsynaptic D2 receptors in the mesoblimic and possibly mesocortical areas of the brain.3

When choosing antipsychotic therapy, consideration must be given to the drug's side effect profile and the neurotransmiters that will be specificially targeted by either a typical (first-generation) or atypical (second-generation) antipsychotic. Chlorpromazine was the first typical antipsychotic to be used, though haloperidol, thiordazine, and perphenazine followed suit. Then came the atypical antipsychotics, which have a greater serotonin-dopamine ratio than the typical antipsychotics.4

Typical antipsychotics are categorized by low, medium, or high potency based on their affinity for dopamine receptors. All antipsychotics generally have 5 side effect profiles that clinicians need to be aware of when selecting such a medication.5 These are:

  • Sedation
  • Anticholinergic side effects
  • Extrapyramidal side effects
  • Weight gain
  • Metabolic side effects

Typical antipsychotics are more likely to cause extrapyrmidal side effects, whereas weight gain and metabolic side effects are more likely to be observed with atypical antipsychotic use. Before an antipsychotic is administered, clinicians must assess the patient’s mood state to identify any marked agitation, which may require the use of an antipsychotic with a greater sedation property. If psychomotor retardation and withdrawal are present, an antipsychotic with fewer sedation properties may be needed.5

The use of antipsychotics has served as a breakthrough for the treatment of psychotic disorders because these drugs can reduce the risk of relapse with continuation of therapy and allow patients to possess some level of appropriate functioning despite the presence of a chronic disease state. The advent of antipsychotics has restored some level of functionality in the thought process, behavioral patterns, and interactions of those with psychotic disorders. Rather than spending the rest of their lives in institutions, affected patients have the opportunity to live in communities and lead active lives.

References

1. Hersen M, Turner S. Beidel D. (Eds.). (2007). Adult psychopathology and diagnosis. (5th ed.). Hoboken, NJ: John Wiley & Sons.

2. Hahn RK, Albers, LJ, Reist C. (2008). Psychiatry. Blue Jay, California: Current Clinical Strategies Publishing.

3. Dipiro et al. (2005). Pharmacotherapy: A Pathophysiologic Approach. (5th ed.). New York: The McGraw-Hill Companies, Inc.

4. Schatzberg AF, Cole JO, DeBattista C. (2010). Manual of clinical

psychopharmacology (7th ed.). Washington, DC: American Psychiatric Publishing, Inc.

5. Preston J, Johnson J. (2011). Clinical Psychopharmacology (6th ed.). Miami, FL: MedMaster Inc.