Changes in cerebral CB1 receptor availability after acute and chronic alcohol abuse and monitored abstinence.

Involvement of the type 1 cannabinoid receptor (CB1R) in the effects of alcohol on the brain is supported by animal experiments, but how in vivo CB1R levels are altered in alcoholic patients is still unclear. To assess the short-time effects of a binge drinking episode on CB1R availability, 20 healthy social drinkers underwent [(18)F]MK-9470-positron emission tomography (PET) at baseline and after intravenous ethanol administration (ALC ACU). Moreover, 26 alcoholic patients underwent sequential CB1R PET after chronic heavy drinking (ALC CHR) and after 1 month of abstinence (ALC ABST). Seventeen healthy subjects served as controls. Compared with baseline, ALC ACU resulted in a global increase of CB1R availability (+15.8%). In contrast, a global decreased CB1R availability was found in ALC CHR patients (-16.1%) compared with controls, which remained unaltered after abstinence (-17.0%). Voxel-based analysis showed that ALC CHR patients had reduced CB1R availability, especially in the cerebellum and parieto-occipital cortex. After abstinence, reduced CB1R availability extended also to other areas such as the ventral striatum and mesotemporal lobe. In conclusion, whereas the acute alcohol effect is an increase in CB1R availability, chronic heavy drinking leads to reduced CB1R availability that is not reversible after 1 month of abstinence. Longer follow-up is required to differentiate whether this is a compensatory effect of repeated endocannabinoid overstimulation or an enduring trait-like feature. An enhanced CB1R signaling may offer a new therapeutic direction for treatment of the negative affective state produced by alcohol withdrawal and abstinence, which is critical for the maintenance of alcohol addiction.

"Caseness" for depression and anxiety in a depressed outpatient population: symptomatic outcome as a function of baseline diagnostic categories.

OBJECTIVE: To examine the diagnostic status of patients enrolled in the Factors Influencing Depression Endpoints Research (FINDER) study and symptomatic outcomes and baseline characteristics associated with remission 6 months after commencing antidepressant therapy. METHOD: Status of clinically diagnosed depressed patients was based on self-rated Hospital Anxiety and Depression Scale (HADS) scores. Five diagnostic categories were defined: noncaseness, mixed anxiety-depression (subthreshold depressive and anxious symptomatology), caseness for depression, caseness for anxiety, and caseness for comorbid anxiety-depression. Assessments included the Somatic Symptom Inventory and health-related quality of life (HRQoL) using the Medical Outcomes Study 36-item Short-Form Health Survey. Remission rates (based on HADS noncaseness for both depression and anxiety) and their associations with baseline characteristics were investigated. Patients were enrolled between May 2004 and September 2005. RESULTS: Of the 3,353 patients enrolled, 66.4% met the HADS criteria for probable depressive disorder and 74.1% met the HADS criteria for probable anxiety disorder. Somatic symptom severity (painful and nonpainful) was highest and HRQoL was lowest in the comorbid anxiety-depression group. After 6 months, remission rates were 50.2% for caseness for depression, 40.4% for caseness for anxiety, and 40.6% for caseness for comorbid anxiety-depression. A lower number of previous depressive episodes, shorter current episode duration, lower painful and nonpainful somatic symptom scores, being married, a higher educational level, and working for pay were most consistently associated with higher remission rates. CONCLUSIONS: Physicians do not always differentiate between anxiety and depressive symptoms when making a clinical diagnosis of depression. At baseline, most enrolled patients had significant emotional depressive and anxious symptoms, as well as significant nonpainful and painful somatic symptomatology, and these factors were associated with outcome.