Response selection deficits in melancholic but not nonmelancholic unipolar major depression.

One consistent functional imaging finding from patients with major depression has been abnormality of the anterior cingulate cortex (ACC). Hypoperfusion has been most commonly reported, but some studies suggest relative hyperperfusion is associated with response to somatic treatments. Despite these indications of the possible importance of the ACC in depression there have been relatively few cognitive studies ACC function in patients with major depression. The present study employed a series of reaction time (RT) tasks involving selection with melancholic and nonmelancholic depressed patients, as well as age-matched controls. Fifteen patients with unipolar major depression (7 melancholic, 8 nonmelancholic) and 8 healthy age-matched controls performed a series of response selection tasks (choice RT, spatial Stroop, spatial stimulus-response compatibility (SRC), and a combined Stroop + SRC condition). Reaction time and error data were collected. Melancholic patients were significantly slower than controls on all tasks but were slower than nonmelancholic patients only on the Stroop and Stroop + SRC conditions. Nonmelancholic patients did not differ from the control group on any task. The Stroop task seems crucial in differentiating the two depressive groups, they did not differ on the choice RT or SRC tasks. This may reflect differential task demands, the SRC involved symbolic manipulation that might engage the dorsal ACC and dorsolateral prefrontal cortex (DLPFC) to a greater extent than the, primarily inhibitory, Stroop task which may engage the ventral ACC and orbitofrontal cortex (OFC). This might suggest the melancholic group showed a greater ventral ACC-OFC deficit than the nonmelancholic group, while both groups showed similar dorsal ACC-DLPFC deficit.

Mental rotation in unipolar major depression.

Mental rotation (MR) performance may be used as an index of mental slowing or bradyphrenia, and may reflect, in particular, speed of motor preparation. MR was employed with a sample of both melancholic (n=8) and non-melancholic (n=9) unipolar depressed patients and healthy controls (n=10) to determine if motor slowing associated with depression might be reflected in slowed motor preparation (as reflected in slope of the MR function) independent of actual motor slowing (overall response time). Both melancholic and non-melancholic patients showed a generalised slowing relative to controls, perhaps reflecting bradykinesia and akinesia. This effect was significantly greater in the melancholic group than in the non-melancholic group. Relative to both the controls and the non-melancholic groups, the melancholic patients showed a progressive slowing with increasing angle of orientation indicating a specific slowing of MR. This deficit suggests a role of slowed motor planning in the psychomotor retardation of patients with melancholic depression.

Better mental health services for young people: responsibility, partnerships and projects.

OBJECTIVE: This paper argues that adolescent psychiatry is best linked with child psychiatry and opposes separate youth mental health programmes for 12-25-year-olds. It reports on the current status of services and considers how adult mental health services (AMHS) can improve services for young adults (18-25-year-olds). METHOD: Factors in development, psychopathology, prevention, training and service systems are reviewed to suggest that current child and adolescent mental health service systems (CAMHS) are appropriate for 0-17-year-olds. Improvements in CAMHS are described from a Victorian perspective, including the model of specialist clinical programmes or teams for specific patient populations. Mechanisms are outlined for AMHS to better assist young adults from 18 to 25 years of age. RESULTS: The model of clinical projects or clinical programme teams, developed in partnership with primary health and others, is a suitable vehicle to help AMHS to improve clinical services to their young adult populations. These may be funded from a variety of sources, including re-engineering existing service resources. CONCLUSIONS: Such developments complement the work of specialist research units and build local competencies. More programme development and evaluation is needed, which will require the support of the College and State and Commonwealth Mental Health Branches.

Parkinsonian motor characteristics in unipolar major depression.

Clinical observation points to similarities between psychomotor retardation in major depression and bradykinesia in Parkinson's disease (PD). While common elements of neuropathology have been proposed to account for this, experimental investigations of this possible link have been few and inconclusive. The present study attempts to determine whether patients with depression display the characteristically Parkinsonian reliance on external cues; and if so, whether this is common to both melancholic and non-melancholic patients. Twenty three patients with unipolar major depression (11 melancholic and 12 non-melancholic) and 24 age-matched healthy controls performed a serial choice reaction time task known to be sensitive to Parkinsonian movement deficits. The melancholic patients showed a Parkinsonian pattern of impairment on the task, exhibiting a particular difficulty when initiating movements in the absence of external cues. This was largely alleviated when a moderate amount of external cueing was provided. At a high level of advance information, melancholic patients were again slow relative to controls. A base-line measure of bradykinesia and a derived measure of dependence upon external cues both correlated significantly with CORE (measure of psychomotor disturbance) ratings. The non-melancholic patients did not show any measurable motor impairment. This cue-dependent deficit may be due to an underlying basal ganglia dysfunction similar to that involved in PD, i.e. a failure of internal cueing. Difficulty with a high level of external cueing might reflect bradyphrenia or a prefrontal motor deficit of ability to plan multiple upcoming movements simultaneously. The results suggest that depression subtypes involve differing patterns of fronto-striatal impairment.