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Digital archive of theses discussed at the University of Pisa


Thesis etd-12102014-223733

Thesis type
Tesi di dottorato di ricerca
Thesis title
Impulsivity in Anxiety Disorders
Academic discipline
Course of study
tutor Dott. Perugi, Giulio
  • Affective Temperaments
  • Anxiety Disorders
  • BIS
  • Cyclothymia
  • Impulsivity
Graduation session start date
Impulsivity is "a predisposition to react in a sudden and unplanned way to internal or external stimuli without regard to the possible negative consequences of these in relation to themselves or others". In the International Diagnostic System, as the DSM-V and ICD-10, impulsivity is mentioned among the operative criteria for many mental disorders and for some of them (impulse control disorders, personality disorders, substance abuse, bipolar disorders) represents a central aspect. The relationship between anxiety and impulsivity is controversial and has received little attention in the scientific literature. Historically, the two dimensions were considered orthogonal, although there are clinical evidences about their coexistence in some psychopathological conditions. Studies on impulsivity are also burdened with several methodological questions: impulsivity is a complex dimension (for example state/trait aspects) and researchers have debated its main constituents to improve the validity of the construct and to provide instrument for a correct evaluation.
The purpose of this research is to assess impulsivity in patients with primary anxiety disorders, using both state and trait measures, and to assess any differences from a control group matched for demographic characteristics. Furthermore, it explores the role of comorbidity with Cyclothymic Disorder (CD) and the relationships with affective temperaments. In particular, our hypotheses are: (a) impulsivity may be greater in patients with anxiety disorders compared to non-psychiatric controls; (b) impulsivity may not be related to the diagnosis of anxiety disorders in itself, but may be mediated by the presence of comorbidity with cyclothymic disorder; (c) there may be a variability in the levels of impulsivity in relation to specific affective temperaments or to affective symptoms; (d) we tried to prove the preceding hypotheses, other than in a mixed case sample of subjects belonging to different diagnostic subtypes, in specific anxiety disorders, beginning with panic disorder.
For this purpose, we evaluated a sample of subjects suffering from anxiety disorders (panic disorder, social phobia, obsessive-compulsive disorder, generalized anxiety disorder) and a sample of control subjects, paired with demographic characteristics, education and occupation. All subjects were exposed to a diagnostic assessment using the Mini Neuropsychiary Interview (MINI); to a symptomatological assessment by the Bach Raephelsen Depression and Mania Scale (BRDMS), the State-Trait Anxiety Inventory (STAI-Y), the Hypomania Checklist (HCL-32) and the Clinical Global Impression (CGI); to a temperamental and personality assessment by the Questionnaire for the Affective and Anxious Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Modified (TEMPS-M), the Separation Anxiety Sensitivity Index (SASI), the Interpersonal Sensitivity Symptoms Inventory (ISSI) and, finally, to a psychometric assessment of trait impulsivity using the Barratt Impulsiveness Scale (BIS) and a neurocognitive evaluation of state impulsivity, using the computerized test Immediate and Delayed Memory Task (IMT/DMT).
For testing hypothesis (a) we enrolled a sample of 47 subjects with different anxiety disorders and 45 matched controls in a period of about 1 year. The case-control comparison showed that subjects suffering from anxiety disorders resulted more impulsive than controls in all the explored measures (i.e. both trait and state components of impulsivity), and reached higher scores on symptomatological and temperamental scales. Thus, patients with anxiety disorders but without a lifetime history of comorbid major mood episodes resulted to have greater trait and state impulsivity than controls.
For testing hypothesis (b) the initial sample of 47 patients has been divided into two subgroups (Cyclo+, n=26 and Cyclo-, n=21) according to the presence, or absence, of comorbidity for cyclothymic disorder. For the diagnosis of cyclothymic disorder, we used both the DSM-IV-TR criteria and also a modified threshold for hypomania with a duration of 2 days. Then we compared symptomatological, temperamental and impulsivity measures in Cyclo+, Cyclo− and controls. The comparisons showed that Cyclo+ are the most impulsive subjects in both trait and state measure and are characterized by greatest symptomatological impairment, highest scores in temperamental scales, and highest levels of interpersonal sensitivity and separation anxiety. Cyclo− subjects resulted to be more impulsive compared to controls concerning the retrospective trait measures, but not in the neuro-cognitive test, a measure of state impulsivity.
For testing hypothesis (c) we enrolled a larger case series of 78 outpatients suffering from anxiety disorders in a period of 2 years. We then correlate BIS and IMT/DMT scores with Brief-TEMPS-35 subscales and BRDMS scores. Correlational analyses showed that cyclothymic and irritable temperaments were significantly related to measure of trait impulsivity, while severity of hypomanic symptomatology to state impulsivity.
Finally, for testing hypothesis (d) we selected, from the previous case series, 64 outpatients who met the DSM-IV-TR criteria for Panic Disorder (PD) with or without Agoraphobia and 44 healthy subjects matched for demographic features. Compared to healthy controls subjects with PD resulted more impulsive in all the explored measures (i.e. both trait and state components of impulsivity), also reporting higher scores in symptomatological and temperamental scales. The comparison between PD patients with (Cyclo+, n=20) and without (Cyclo−, n=44) comorbid cyclothymic disorder and controls (n=44) showed that Cyclo+ were the most impulsive subjects in all the investigated measures and were characterized by the greatest symptomatological impairment, the highest scores in temperamental scales, and the highest levels of interpersonal sensitivity and separation anxiety.
In conclusion, in our clinical records, as hypothesized, trait and state impulsivity resulted greater in patients with primary anxiety disorders than in matched controls. Moreover, impulsivity seemed not to be connected to the Anxiety Disorder diagnosis in itself, but it seemed to be mediated by comorbidity with cyclothymic disorder. Moreover, trait and/or state impulsivity levels resulted variable and seem to be associated with specific affective temperamental traits or with affective symptoms. In particular, trait impulsivity could be attributed to the temperament disposition, while state impulsivity to current hypomanic symptomatology. It was finally possible to replicate the results, previously obtained in a the mixed case sample of subjects belonging to different diagnostic disorder subtypes, in a sample of patients with panic disorder.