Psychophysiological mechanisms in panic disorder: a correlative analysis of noradrenaline spillover, neuronal noradrenaline reuptake, power spectral analysis of heart rate variability, and psychological variables.

BACKGROUND: The risk of adverse clinical cardiac events is increased in patients with panic disorder (PD). We evaluated possible mechanistic links between PD and heart disease. We estimated cardiac vagal activity from heart rate variability (HRV) measurements and quantified sympathetic nervous system (SNS) activity using plasma noradrenaline tracer kinetics methodology. METHODS: Thirty-nine people with PD and 39 age- and gender-matched healthy volunteers were studied. In 19 participants with PD, both HRV and plasma noradrenaline kinetics were tested; in 20 with PD and 20 healthy volunteers, HRV measurements only were made, whereas in 19 healthy volunteers, noradrenaline kinetics only was tested. All panic disorder participants completed psychological measures of anxiety sensitivity and state and trait anxiety; healthy volunteers in whom HRV was measured also provided psychological measures. RESULTS: Sympathetic nervous tone in the heart, based on rates of cardiac noradrenaline spillover, was normal in PD. Noradrenaline and adrenaline plasma clearance and plasma tritiated noradrenaline and adrenaline extraction in transit through the heart, all dependent on the noradrenaline transporter (NET), were reduced in PD. Psychometric testing linked inhibition of anger to this deficit in NET functioning. Anxiety sensitivity was specifically associated with impaired cardiac NET. High- and low-frequency heart rate spectral power was unrelated to all plasma noradrenaline kinetics measurements. CONCLUSION: Defective neuronal reuptake of noradrenaline, by augmenting the sympathetic neural signal in the heart, might have a dual effect, sensitizing the heart such as to lead to symptom development (and thus perhaps causing panic disorder) and, second, potentially contributing to adverse cardiac events in established PD.

Modification of the Body Sensations Interpretation Questionnaire (BSIQ-M): validity and reliability.

The catastrophic misinterpretation model [Behav. Res. Ther. 24 (1986) 461-470] proposes that panic attacks result from misinterpretation of interoceptive stimuli as precursors to physical or psychological emergency. Inconclusive evidence for the model may be partly explained by limitations of the questionnaires developed to measure catastrophic misinterpretation. For example, the Body Sensations Interpretation Questionnaire (BSIQ) is unable to clarify whether anxiety-related interpretations of ambiguous interoceptive stimuli represent catastrophic misinterpretations or responses masking feared outcomes (e.g., heart failure). Additionally, it lacks items relating to several DSM-IV criteria for panic, thereby limiting content validity. Reliability is also potentially compromised due to experimenter-coding of participant-generated responses. A modified form of the BSIQ was developed to address these limitations and evaluated with non-anxious controls (n=34) and people with panic disorder (n=38). The revised questionnaire demonstrated good to excellent internal consistency, inter-rater reliability, and construct validity and is a useful development of the BSIQ.

Efficacy of internet therapy for panic disorder.

Fifty-five people with panic disorder (PD) were randomised to internet-based cognitive behavioural panic treatment (CBT) (with email contact), therapist-assisted CBT manual or information-only control (both with telephone contact). Both CBT treatments were more effective in reducing PD symptomatology, panic-related cognition, negative affect, and number of GP visits and improving physical health ratings. Internet treatment was more effective than CBT manual in reducing clinician-rated agoraphobia and number of GP visits at post-assessment. At follow-up, these effects were maintained for both CBT groups, with internet CBT better at improving physical health ratings and reducing GP visits. This study provides support for the efficacy of internet-based CBT.

Barriers to the effective management of depression in general practice.

OBJECTIVE: The aim of this study was to investigate the effects of prior general practice training in mental health and practice location on general practitioner (GP) attitudes toward depression, self-confidence in assessing and treating depressed patients, identification of doctor, patient and practice barriers to the effective care of depressed patients in general medical practice and GP-reported current clinical practice. METHOD: Fifty-two (out of 123) Divisions of General Practice that responded to an invitation to participate in the study distributed 608 anonymous surveys to a representative sample of GPs; 420 (69%) were returned. The questionnaire focused on current clinical practice, perceived barriers to care of depressed patients and doctors' self-efficacy for assessing and treating depressed patients. It also consisted of two scales, based upon previous research, designed to assess doctors' attitudes towards depression and depressed patients. RESULTS: General practitioners who had undertaken mental health education and training more often used non-pharmacological treatments (p=0.00), as did female GPs (p=0.00). Male GPs (p=0.00) and those in rural settings (p=0.01) more often prescribed medication for depression. Those without mental health training more often identified incomplete knowledge about depression as a barrier to its effective management (p=0.00). Urban-based GPs (p=0.04) and those with prior mental health training (p=0.00) were more confident in the use of non-pharmacological treatments. Female GPs without mental health training were the least confident in the use of these methods (p=0.01). Overall, GPs with mental health training were more positive in their attitudes toward depression and their treatment of these patients (p=0.00). Female GPs appeared more positive in their attitudes toward depression than male GPs (p=0.01), although the results were not entirely consistent. CONCLUSIONS: Participation in mental health training by GPs appears to be related to their attitudes toward depressed patients and to their confidence and abilities to diagnose and manage the common mental disorders effectively.

Clinical psychology in general practice: a cohort study.

OBJECTIVE: To evaluate whether a collaborative model of mental healthcare involving general practitioners and clinical psychologists benefits patients with common mental disorders in primary care. DESIGN AND PARTICIPANTS: Cohort study of 276 general practice patients with mental health problems receiving collaborative treatment from clinical psychologists and GPs compared with a normative sample of 198 patients attending the same general practice surgeries. SETTING: Nine general practices in three regional cities (Bathurst, Armidale and Ballarat) and two single-doctor practices in two rural and remote townships (Rylstone and Trundle). Data were collected in Bathurst, Rylstone and Trundle during 2001 and 2002 and in Ballarat and Armidale in 2002. INTERVENTION: Full assessment, case formulation and "focussed psychological interventions" relevant to the patient's condition. MAIN OUTCOME MEASURES: Level of psychological dysfunction assessed before and after the intervention, using the DASS (Depression, Anxiety and Stress Scales), GHQ (General Health Questionnaire) and GWBI (General Well Being Index) scales. RESULTS: After the intervention, average scores in the treatment group decreased significantly (P < 0.001) on all DASS and GHQ measures and increased on the GWBI, indicating a positive change in the patients' mental health. The follow-up scores of the treatment and normative groups did not differ significantly on any of these measures. CONCLUSION: Preliminary findings suggest that collaborative care involving GPs and clinical psychologists provides significant gains in patients' mental health.

Australian GPs' preferences for education about depression and related disorders.

OBJECTIVE: To investigate Australian general practitioners' experiences of accessing education about depression and their preferences for future education on depression and related disorders. METHOD: Six hundred and eight anonymous surveys were distributed to GPs through 52 rural and urban divisions of general practice; 420 were returned. RESULTS: Educational formats involving direct contact with people having mental health expertise were highly valued. Distance education and web based technologies were least used. In the previous year, women and older GPs had spent more time on education about depression. Most intended to undertake more such education in the future and said that education in psychosocial strategies would be very useful. General practitioners' attitudes to further education about depression were influenced by their gender, practice location, and their previous mental health training. DISCUSSION: More face-to-face training may be desirable to take advantage of GPs' willingness to spend more time on education about depression and related disorders.