Individuals with focal brain damage have minimal RA.Isolated RA is associated with a visible thalamic lesion. Consistent with other forms of RA, the isolated form is marked by the inability to recall past information.Pure retrograde amnesia (PRA) refers to the behavioral syndrome that is characterized by the inability to retrieve remote information in the face of a normal ability to learn new information, with no other ecological or psychometric evidence of cognitive impairment. It should not be confused with brief periods of peritraumatic amnesia that are common in mild concussive head traumas. The findings of pure retrograde amnesia have helped form the dissociation between mechanisms for RA and AA. Several studies have found numerous causes for PRA like vascular diseases, head traumas ranging from mild to severe, encephalitis, as well as purely psychological conditions and totally unidentifiable etiologies. Most people who have PRA can function normally and learn new informationA pure form of RA is rare as most cases of RA co-occur with AA. A famous example is that of patient ML. The patients MRI revealed damage to the right ventral frontal cortex and underlying white matter, including the uncinate fasciculus, a band of fibers previously thought to mediate retrieval of specific events from ones personal past.During consolidation, the hippocampus acts as an intermediate tool that quickly stores new information until it is transferred to the neocortex for the long-term. The temporal lobe, which holds the hippocampus, entorhinal, perirhinal and parahippocampal cortices, has a reciprocal connection with the neocortex.
The overall rate and degree of treatment success is somewhat lower than for non-chronic depression, and a combination of psychotherapy and pharmacotherapy shows best results. Therapy
Psychotherapy can be effective in treating dysthymia. In a meta-analytic study from 2010, psychotherapy had a small but significant effect when compared to control groups. However, psychotherapy is significantly less effective than pharmacotherapy in direct comparisons.There are many different types of therapy, and some are more effective than others. The empirically most studied type of treatment is cognitive-behavioral therapy. This type of therapy is very effective for non-chronic depression, and it appears to be also effective for chronic depression. Cognitive behavioral analysis system of psychotherapy (CBASP) has been designed specifically to treat PDD. Empirical results on this form of therapy are inconclusive: While one study showed remarkably high treatment success rates, a later, even larger study showed no significant benefit of adding CBASP to treatment with antidepressants. Schema therapy and psychodynamic psychotherapy have been used for PDD, though good empirical results are lacking. Interpersonal psychotherapy has also been said to be effective in treating the disorder, though it only shows marginal benefit when added to treatment with antidepressants. Medications
In a 2010 meta-analysis, the benefit of pharmacotherapy was limited to selective serotonin reuptake inhibitors (SSRIs) rather than tricyclic antidepressants (TCA). According to a 2014 meta-analysis, antidepressants are at least as effective for persistent depressive disorder as for major depressive disorder.