This patient's clinical presentation is consistent with schizoid personality disorder (SPD), which does not require treatment, unless the patient presents with a co-morbid Axis I disorder, such as depression, psychosis, or anxiety.
SPD is a cluster A personality disorder characterized by social withdrawal and aloofness without bizarre beliefs. Importantly, it differs from avoidant personality disorder (cluster C), in that patients with SPD do not have a desire to be more social. It differs from schizotypal personality disorder, in that patients with SPD do not hold bizarre beliefs. Because patients with this disorder often willfully withdraw from society, they are very likely to go undiagnosed by physicians. Talk therapy can be attempted as a modality of treatment, but it is typically only effective for acute bouts of stress or anxiety. Patients with co-morbid depression or psychosis may benefit from antidepressants.
Ward discusses the management of personality disorders in the primary care setting. He notes that patients with SPD may experience anxiety when visiting physicians due to forced contact with other people. This may result in a delay in seeking care, and in the patient appearing non-appreciative. He suggests that physicians avoid trying to become over-involved with patients with SPD.
Triebwasser et al. review the current data on SPD. They note that some psychiatrists believe that all SPD patients fall under the category of "affect restricted" or "seclusive," and that the correct diagnosis of these patients is actually schizotypal or avoidant personality disorder. They conclude that it would be reasonable to remove schizoid personality disorder from the next Diagnostic and Statistical Manual of Mental Disorders.
Illustration A is a chart depicting the 10 different personality disorders and their symptoms.
Answer 1: Schizotypal, not schizoid, personality disorder is related to schizophrenia.
Answer 2: Since this patient does not present with symptoms of co-morbid depression, he does need to be treated with antidepressants.
Answer 4: Patients with SPD are often indifferent to praise or criticism, and likewise do not offer praise or criticism as readily as non-affected patients.
Answer 5: Patients with antisocial, borderline, or schizotypal personality disorders are likely to have substance use disorders, but not patients with schizoid personality disorder (Hasin et al).
Ward, RK. Assessment and management of personality disorders. Am Fam Physician. 2004 Oct 15;70(8):1505-12.
PMID:15526737 (Link to Abstract)
Triebwasser J, Chemerinski E, Roussos P, Siever LJ. Schizoid Personality Disorder. J Pers Disord. 2012 Dec;26(6):919-26.
PMID:23281676 (Link to Abstract)
Hasin D, Fenton MC, Skodol A, Krueger R, Keyes K, Geier T, Greenstein E, Blanco C, Grant B. Personality disorders and the 3-year course of alcohol, drug, and nicotine use disorders. Arch Gen Psychiatry. 2011 Nov;68(11):1158-67. doi: 10.1001/archgenpsychiatry.2011.78
PMID:22065531 (Link to Abstract)